Powerful Irma Threatens to Put South Florida Underwater, Spill Lake Okeechobee

Near category five strength Irma represents a major flood threat from storm surge and rainfall to South Florida. Due to its large size, strong winds, its movement toward shore atop rising seas, and ability to push a tall and wide-ranging surge of water over far-flung coastlines, Irma has the potential to put major cities like Miami under water. In addition, expected 10-15 inch rainfall over Lake Okeechobee threatens the integrity of an aging dike which, if overtopped, could result in severe flooding of inland communities.

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As of the 5 PM advisory from the National Hurricane Center, Irma was a top-strength category 4 hurricane packing 155 mile per hour maximum sustained winds and a minimum central pressure of 925 mb. The storm is presently tracking just north of Cuba along a westerly or west-northwest path. It is expected to turn north by Saturday, ultimately making landfall somewhere in South Florida.

Like Harvey, Irma is very moisture rich. Like Harvey, Irma is set to interact with a deep trough dipping down over the Eastern U.S. Like Harvey, Irma is tapping warmer than normal surface waters off Florida which is helping the storm to maintain a high intensity. And like Harvey we can confidently say that the record-breaking and long-lasting high intensity of Irma has been fueled by human-forced climate change — with some weather models indicating a risk that Irma could restrengthen on approach to Florida as it crosses over the 3.5 degree F warmer than normal waters of the Gulf Stream.

Unlike Harvey, Irma is expected to continue moving after making landfall. And this movement will prevent the kind of prolonged event that occurred during Harvey — with a tropical system raining out over the same region for days and days on end. That said, Irma’s extremely strong winds presently at 155 mph and what is likely to be a very powerful storm surge pose a threat to most locations along the Florida Peninsula — especially South Florida. As with other recent hurricanes like Sandy and Matthew, Irma presents an even greater threat from storm surge flooding due to higher overall ocean levels as a result of melting glaciers in places like Antarctica and Greenland. So Irma’s massive predicted surge is running in on a higher ramp than that of decades past.

(The NAM 3 kilometer model shows a very intense 896 mb storm off South Florida by 10 PM Saturday. This model forecast shows Irma strengthening to a very extreme Category 5 storm over the much warmer than normal waters of the Gulf Stream. Official forecasts from the National Hurricane Center still call for a weaker, but still strong and dangerous, Category 4 or 5 system threatening South Florida at about this time. Image source: Tropical Tidbits.)

According to the National Hurricane Center, preliminary expected storm surges range from 8-12 feet for SW Florida from Captiva to Cape Sable, 5-10 ft from Cape Sable to Boca Rato including the Florida Keys, 5-8 ft from Venice to Captiva, 3 to 6 ft from Boca Raton to the Velusia County line, and 3 to 5 ft from Anclote River to Tampa (note that both Florida coasts expect moderate to severe storm surges and that these totals are increased and expanded from the 2 PM NHC advisory).

To put these numbers in perspective, pretty much all of South Florida, including most of the city of Miami is below 10 feet above sea level. A 10 foot storm surge with breaking, wind-driven waves on top, would therefore have catastrophic impacts for this region (see graphic below). As Irma approaches, these already significant storm surge projections may rise further even as impacts from storm surge are likely to expand up the coast.

(A ten foot rise in base sea levels as could occur during Irma’s storm surge would put most of South Florida under water. Storm surge projections for this region are presently 8-12 feet and 5-10 feet. Note that storm surge impact can vary widely based on location and that changes in Irma’s projected path is likely to alter its storm surge related impacts. Image source: Climate Central.)

Though Irma has been compared with Andrew, we must note that Irma is a significantly larger storm — dwarfing the tiny but intense Andrew. As a result, Irma has the ability to deliver a lot more in the way of a powerful surge of water to both Florida coasts. And where Andrew’s damages were primarily due to extremely high winds, Irma’s damages are likely to come from both wind and water — with the potential for very severe storm surge and flood-based destruction.

In addition to the problem of Irma’s likely large and wide-ranging surge, a second issue is the fact that there’s some concern that an aging dike holding water back from communities near Lake Okeechobee might not withstand projected rainfall totals from Irma of 10-15 inches. Though not Harvey-level rainfall amounts, these rains would come in very intense bands over the course of perhaps one day. Such heavy rainfall could cause the lake to over-top the dike — resulting in severe flooding for downstream communities.

 

(Irma’s heaviest rains are expected to fall over Lake Okeechobee — adding to an already significant flood risk to South Florida. Image source: NOAA.)

The seventy year old dike is presently vulnerable not just due to its age, but also due to the fact that a construction project aimed as shoring up the dike is underway. This rebuild in progress makes the dike even more vulnerable to heavy rains and to large waves that would be stirred up on the lake by hurricane force winds. The Army Corps of Engineers has reassured the public that a dike breach is unlikely — as its most vulnerable section in the southeast has already been strengthened. Concern remains, however, that flooding from the dike could combine with a backing up of canals due to storm surge to swamp communities far inland from the coast.

(UPDATED — UPDATES TO FOLLOW)

RELATED STATEMENTS AND INFORMATION:

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A Visibly Extreme Jet Stream in Advance of Irma

On Tuesday, I wrote this blog about how Jet Stream behavior and related severe weather during summer of 2017 jibed with the findings of recent climate science. About how human-forced polar warming appears to be impacting extreme summer weather patterns by altering the upper level winds — with a particular focus on impacts to North America.

Yesterday, I looked at the upper level wind patterns running over North America in advance of Irma’s approach and saw this:

(Classic ridge-trough pattern like that identified by Dr Jennifer Francis and Dr Michael Mann. One that, according to their related research, increases the likelihood of certain kinds of extreme weather patterns and events. One that these scientists associate with polar warming set off by human-caused climate change. Image capture from 1500 UTC on September 6. Image source: Earth Nullschool.)

It’s a classic high amplitude wave form in the Jet Stream. One that shows an extremely deep trough digging all the way down to the Gulf Coast in the east and arching back up into a pointed ridge north of Alaska and into the Arctic Ocean in the west. This kind of high amplitude wave pattern is not typical. Or if such a pattern did appear in the past, it tended not to stick around for so long. But during this summer, such intense high amplitude ridges have been forming again and again over the west and such deep troughs have been forming again and again in the east.

New Precipitation and Temperature Extremes

The most apparent visible effect of this ridge-west — trough-east pattern has been to produce record heat, drought, and wildfires in the west and record rainfall in conjunction with an extremely stormy weather pattern in the south and east. You can plainly see this dipolar relationship in the precipitation and temperature anomaly maps provided by NOAA below:

These maps cover precipitation and temperature observations for the last 30 days compared to climatological averages. In the west we find that precipitation for large regions has been less than 10 percent of normal (less than 1/10th normal). Meanwhile temperatures in the west have ranged between 1 and 4 C above average. In the south and east, large regions have seen between 200 and 800 percent of typical precipitation amounts (2 to 8 times the norm). Temperatures, meanwhile have ranged between 1 and 3 C below average.

This is the very definition of heightened extremes. Looking at the prevalent upper level air pattern over the U.S. for the summer of 2017, it’s clear that south to north upper level winds pulling air up from the Equatorial zone toward the pole are facilitating one side of the extreme and that a countervailing upper level wind originating near the pole and running south toward the tropics is driving the opposite extreme.

Slowing Upper Level Winds in a North-South Orientation Weakens the Steering Currents

Unfortunately, prevalent and long lasting heat or heavy rainfall isn’t the only apparent impact of this new pattern. Another aspect of this extreme dipole is a weakening of the west to east steering currents that typically begin to pick up in a region between 25 and 30 degrees North Latitude and to intensify further beyond the 30 N line. This effect is due to the fact that upper level wind patterns are oriented more in a north-south (west) or south-north (east) direction and due to the fact that under such large Jet Stream meanders the upper level steering winds tend to slow down.

(It’s not just Harvey and Irma. Weak upper level steering currents are contributing to a long range potential that Jose might loop back to strike South Florida.)

For Hurricanes like Harvey and Irma, stronger west to east steering winds have had two protective effects for the United States. First, they have helped storms to keep moving — working to generally prevent the kind of long duration stall we saw that helped to produce such catastrophic flooding during Harvey. Second, they have tended to deflect storms away from the U.S. East Coast. And for Irma, what this means is that this storm is more likely to strike the U.S. East Coast if the upper level steering winds that would typically turn it to the east are weak.

This is a dynamic upstream aspect of human-forced polar warming. One that produces added extreme weather risks on top of those already generated by warming ocean waters — which increase peak potential storm intensity — and rising atmospheric water vapor — which helps to add latent heat, lift and related convective available potential energy that increases top limits for storm intensity and heavy rainfall.

And as we sit here hoping and praying that Irma will re-curve away from the U.S. east coast, we should consider how polar warming may be helping to make such a terrible strike more likely — increasing risks to so many people and to so much that we all hold dear.

RELATED STATEMENTS AND INFORMATION:

Links:

Dr Jennifer Francis

GFS Model Runs illustrated by Earth Nullschool

Extreme Weather Events Linked to Climate Change’s Impact on Jet Stream

This is the Pattern Climate Scientists Warned us About

NOAA

Hat tip to Scott

Hat tip to Wharf Rat

Models Show Irma Tracking Toward 88 Degree (F) Waters Before Setting Sights on Florida, Georgia and South Carolina

As of yesterday and today, Irma was the strongest storm ever to form in the Central Atlantic. Fueled by record atmospheric and ocean heat and related high atmospheric moisture content, the storm plowed into the Leeward Islands of Barbuda, St. Martin and Anguilla as a top-strength Category 5 monster hurricane.

(Alex Woolfall takes shelter in a concrete stairwell in St. Martin to avoid Irma’s catastrophic winds. It’s worth noting that hurricanes are heat engines. Tapping 87 F sea surface temperatures and producing 100 percent humidity would result in the very hot conditions Alex was experiencing 7 hours ago. We’re all pulling for Alex and those like him who were trapped in the belly of this massive beast. His last report was at 5:45 AM.)

As Irma’s eyewall began to pass over Barbuda, a reporting station recorded a wind gust of 155 mph before it was knocked out. That island of 1,800 people is now completely cut off from the outside world. Having just experienced winds in excess of those hosted by Andrew and Camille, it is likely that catastrophic damage was inflicted.

On St. Martin, which also passed through Irma’s eye and most intense wind bands, initial reports are also showing very considerable damage. Four of the strongest buildings on the island have been destroyed. And it is expected that most structures across this French/Dutch shared island which is home to 75,000 have seen moderate to catastrophic damage.

(Footage this morning, apparently taken from a camera near the airport at Simpson Bay in St. Martin shows debris, flooding, and very strong winds.)

Anguilla, which is north of St. Martin and is home to another 15,000 souls, passed through the northern eye wall. This is typically the most intense part of a hurricane. So far, reports from Anguila are spotty. But the damage there is likewise expected to be catastrophic.

As of the 5 PM advisory, according to the National Hurricane Center, Irma is still a devastatingly powerful Category 5 monster hurricane hosting maximum sustained winds of 185 mph. The storm had seen some weakening due to apparent eyewall replacement and mild wind sheer — which pushed pressures back up to 920 mb from a low of 914 mb last night earlier today. However, this weakening was not significant enough to impact Irma’s amazing wind intensity. Since that time, Irma’s central dense overcast has thickened while pressures have dropped back down to 914 mb as of the 5 PM advisory.

(Irma tracking just slightly north of the officially projected path from the NHC as of early afternoon on Wednesday. Image source: The National Hurricane Center.)

As the storm passes toward the Virgin Islands, roars by Puerto Rico, and howls into the Turks, Caicos and Bahamas, it is likely that some weakening will occur. Despite this fact, the storm is expected to maintain Category 5 intensity through at least the next 48 hours. After 72 hours, the official forecast calls for Irma to drop to strong Category 4 intensity and eventually a strong Category 3 by Monday. However, some models like the GFS show Irma again strengthening as it taps very warm waters off Florida.

(Very hot sea surface temperatures off Florida could provide fuel that allows Irma to strengthen a second time as predicted in forecast models like the GFS. Image source: Earth Nullschool.)

Most models are now starting to settle on a consensus that brings Irma toward Florida and along a course that may threaten Georgia and South Carolina. The GFS model shows Irma tapping extremely hot sea surface temperatures in the range of 88 degrees Fahrenheit (about 3.5 F hotter than average) and pumping up again into very strong Category 5 intensity with an 895 mb minimum central pressure off Florida by Sunday. This would be a stronger intensity than the 914 mb reached last night by measure of pressure alone.

(The GFS, ECMWF and other major models are starting to agree on a consensus track which has Irma raking the Florida coast before threatening Georgia and the Carolinas. Image source: The National Hurricane Center.)

GFS shows the storm raking most of the Florida coast as it bounces from one landfall or near landfall to another across the eastern seaboard before making a final landfall as a 924 mb monster along the Georgia-South Carolina border. Meanwhile, another major model — the Euro (ECMWF) — has the storm following approximately the same path at a lower intensity.

Though the GFS modeled intensity does not jibe with the official forecast — which calls for weakening of Irma to strong Cat 4 and then strong Cat 3 status — we should not completely rule out the GFS prediction due to those very warm ocean surfaces mentioned above. If predicted wind shear does not emerge, then it would allow Irma to more effectively tap those very warm waters off Florida and hit a second peak intensity. And if such a forecast were realized, it would produce a seriously catastrophic disaster for the U.S. East Coast.

(Models are starting to come into consensus on Irma’s track — which is zeroing in on it raking the Florida coast and then slamming into Georgia or South Carolina — but forecast intensity varies widely. GFS shows Irma off Florida at an intensity stronger than her present extreme strength by Sunday. Image source: Tropical Tidbits.)

Of course, the official forecast track and intensity — in which a strong Category 4 storm rakes coastal Florida and then tracks up into Georgia or South Carolina to make final landfall as a strong Cat 3 is bad enough. So in this case, we are looking a present forecast scenarios in which models are starting to come into consensus on track that range from bad (official Cat 4 and then Cat 3 intensity storm impacting Florida, Georgia and the Carolinas) to worse (GFS potential for a very strong cat 5 storm threatening the U.S. Southeast Coast).

(UPDATED — UPDATES TO FOLLOW)

STATEMENTS AND RELATED INFORMATION:

Links:

The National Hurricane Center

Earth Nullschool

Tropical Tidbits

Strongest Central Atlantic Hurricane on Record — Dangerous 185 MPH Irma Defies Intensity Projections

As of the 8 PM advisory from the National Hurricane Center (NHC), Hurricane Irma was located 85 miles east of Antigua moving west at 15 mph. The storm hosted maximum sustained winds of 185 mph and a minimum central pressure of 916 mb.

This is an intensity considerably stronger than that previously projected or even expected as an outlier possibility for today. One that has heightened concern over an already powerful storm. A storm that is drawing extra energy from an atmosphere and ocean warmed by climate change.

Though moving west at this time, Irma is expected to turn toward the west-northwest. On its present and predicted path, the NHC expects severe hurricane conditions including hurricane force winds, very tall and destructive breaking waves, and life-threatening 7-11 foot storm surges to start impacting the extreme northern Leeward Islands by late Tuesday afternoon and early evening.

A Worrisome Set of Forecasts 

The storm is expected to continue on a west and then west-northwest track bringing it close to Puerto Rico and the Dominican Republic and over the Turks and Caicos and southeastern Bahamas by Thursday. After which time, the storm is expected to skirt the northern coast of Cuba before turning toward the Florida Keys on Saturday.

(National Hurricane Center’s official path brings Irma to the Florida Keys by Sunday. Image source: NHC.)

The current official National Hurricane Center forecast has the storm maintaining major hurricane status all along its projected path. Category 5 intensity is expected to be maintained for much of the next three days after which time the NHC projects Irma to weaken a bit — remaining in the very dangerous, strong category 4, range.

Meanwhile, various models, including GFS and SHIPS produce a very severe Category 5 storm featuring intensities from 895 to 910 mb in the vicinity of U.S. southeast by Saturday through Monday. This storm is, therefore, very dangerous and is likely to stay that way for some time — barring a close interaction with the mountains of Puerto Rico or Hispaniola or a prolonged landfall over Cuba.

(The present GFS model run shows a nightmare scenario for the Carolinas with an 890 mb hurricane on approach by Monday. It’s worth noting that the official NHC projected track is more to the south with a weaker — but still very dangerous — category 4 storm in the region of Florida by late Saturday. Image source: Tropical Tidbits.)

Strongest Central Atlantic Storm on Record

The storm’s present intensity is now among the strongest storms ever to form in the Atlantic, Gulf or Caribbean. An earlier report from Weather Underground found that Irma, at 180 mph maximum sustained winds, was already the 5th strongest Atlantic storm as measured by wind speed. Irma has since strengthened to 185 mph —  tying it with Wilma, Gilbert and the Labor Day Hurricane as second strongest Atlantic storm as measured by maximum winds. The strongest was Allen at 190 mph.

It’s worth noting that the Carribean and Gulf of Mexico are included in Atlantic hurricane listings. However, most of the top intensity storms have formed in these typically warmer seas. Irma, on the other hand, has reached such extreme strength over the typically cooler waters of the Central Tropical Atlantic. Though these waters, as with everything else that has been altered by human-caused climate change, are today warmer than they were in the past. As a result, the storm is now the strongest hurricane ever to form in that open water region.

NHC official forecast projections keep the storm quite strong as it moves into the warmer Carribean, though eventually weakening to CAT 4, as it moves west. Meanwhile, some models (GFS and SHIPS) show potential for an even more intense storm as Irma approaches Florida, the Gulf or the SE U.S. (strong CAT 5 that may dip into the 890 mb range).

Evacuation Orders Posted as Storm Defies Intensity Models

Officials appear to be very worried. Already evacuation orders and closings have been listed for Florida as interests across the Southeast take notice. This caution is wise. Irma has the potential to produce worse impacts than Harvey. So all interests should remain vigilant.

Irma is presently exceeding both its predicted and its top predicted storm intensities — defying traditional storm prediction models like SHIPS. This is another concerning development for a powerful storm in a warming climate. That said, if the storm tracks further west (and some models show the storm tilting in this direction), interaction with large Caribbean islands will tend to reduce the storm’s intensity as it approaches the U.S.

This storm appears to be very efficiently tapping warmer than normal sea surfaces and a moister than normal atmosphere in order to spike its peak intensity. Two conditions set in play by human-caused climate change that are now helping to make storms like Irma both more intense and more dangerous. And it’s a condition that we need to take into account as we follow the track of Irma toward U.S. shores.

(UPDATED — UPDATES TO FOLLOW)

RELATED STATEMENTS AND INFORMATION:

Links:

National Hurricane Center

Tropical Tidbits

Irma — 5th Strongest Atlantic Hurricane on Record

Hat tip to eleggua

Hat tip to wili

U.S. Electrical Vehicle Sales Growth Continues Ahead of Model 3 Tsunami

During August of 2017, U.S. electrical vehicle sales continued to increase at a respectable pace year-on-year.

According to Inside EVs, total sales for electric-powered cars in the U.S. totaled 16,624 during August. This represents another record — growing by 2,032 or 12.2 percent above 2016’s previous record August total of 14,592.

The Tesla Model S and Chevy Bolt EV held the first and second rank among individual model sales by sending 2150 and 2107 vehicles out to new owners respectively. The 238 mile range Bolt priced at $36,000 before incentives continued to show strong sales growth as Chevy accelerated expanding offerings to new states across the U.S. Model S sales, while holding top position, were down year-on-year — likely in part due to anticipation of the Model 3 ramp-up.

(Elon Musk recently reassured investors that the Model 3 will achieve its 10,000 per week production target in 2018. Image source: EV Network.)

Inside EVs estimates that 75 of the game-changing Model 3 — with best in class features, a 220 to 310 mile range, and a 126 MPGe fuel efficiency rating — were produced and sent to customers during August. If this number is correct, it would signify a somewhat slower ramp than the expected 100 sales for the month. However, this report is preliminary and may be subject to revision. And there have been more than one or two hints circulating around the web that Tesla is actually ahead of its production goals — hitting 200 vehicles by end August (see tweet below).

Presently ranked 30th on the EV sales chart for all of 2017, the Model 3 (with its approximate half-million reservations) is likely to climb into the top 20 by end September. At that point, Tesla expects about 1,500 Model 3s to be produced monthly. By October, monthly sales of the Model 3 may eclipse all other U.S. EVs as production exceeds 5,000.

At this point, the Model 3 will likely start having a noticeable influence on overall U.S. EV sales — with that impact further dilating during November and December. And if Tesla meets its December sales goal of 20,000 units for the Model 3, then the U.S. overall may see December 2017 total EV sales from all models nearly double December 2016 numbers (of nearly 25,000 units).  Meanwhile, through 2018, the Model 3 could help to drive total U.S. EV sales to around half a million or more.

In other words, the U.S. EV market is about to be hit by a tidal wave of very high quality and relatively low cost Model 3s — with profound and long-lasting results. This is good news for renewable energy and climate change response advocates. For such a large wave of electrical vehicles coming to market provides considerable opportunity for reduced carbon emissions from both vehicle based fossil fuel burning and from the ancillary electrical power market where batteries used for EVs can also replace base load coal and gas fired power stations with energy storage linked to wind and solar.

Links:

Monthly Plug-in Sales Scorecard

Plug In Electric Car Sales for August

Tesla Model 3 Production

Tesla Model 3 Information

This is the Climate Pattern Scientists Warned Us About — Wildfires Approach 8 Million Acres in U.S. During Summer of Extreme Western Heat, Severe Eastern Storms

“If the same weather persists for weeks on end in one region, then sunny days can turn into a serious heat wave and drought, and lasting rains can lead to flooding.” — Dr. Stefan Rahmstorf.

“The warming of the Arctic, the polar amplification of warming, plays a key role here. The surface and lower atmosphere are warming more in the Arctic than anywhere else on the globe. That pattern projects onto the very temperature gradient profile that we identify as supporting atmospheric waveguide conditions.”Dr. Michael Mann.

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To say that, for the U.S., it’s been hot out west and stormy in the east this summer is a bit of an understatement. For while the east has seen numerous storms producing local-to-national record rainfall amounts, the west has been baking under heatwaves that appear to have set off one of the worst years for wildfires nationally on record. This is an extreme summer weather pattern that recent scientific studies have linked to human-caused climate change.

(Severe western wildfires blanket northern U.S. under a massive plume of smoke. Image source: NASA Worldview.)

Last week, extreme heat baked the U.S. west coast. On Friday, San Francisco hit a record high of 106 degrees (F), striking up to 102 (F) on Saturday. Regions further inland near Eureka hit a Death Valley-like 115 F.  36 million Californians fell under a heat advisory as excessive heat warnings ranged on up the west coast through Oregon, Washington, and British Columbia.

The heat wave — which was just the most recent of many for the region this year — baked hills and valleys covered with new vegetation springing up after unusually heavy winter rains. Setting off a spree of wildfires that has seen very severe burn rates throughout summer.

Los Angeles County in Burbank experienced its largest fire on record Saturday as a massive blaze swept through the hills — igniting 7,000 acres before being tamped down by the oddly northward tracking remnants of a tropical storm drifting through the region on Sunday.

The fire spurred the response of 1,000 firefighters, forced 700 people to evacuate, closed route 210 for a time and consumed three homes. Assisted by the rains and moisture flowing off the remnants of Lidia, firefighters have now managed to contain 30 percent of this particular blaze. But with many more fires continuing to burn throughout the west, the region is far from out of the proverbial woods.

According to the National Interagency Fire Center, 70 large fires continue to burn in the western states of Montana, California, Oregon, and Washington. The vast majority of these fires remain uncontained. And at least two exceed 100,000 acres in size. Smoke from these fires has been cycling into the upper level winds for some time now — with most of the northern U.S. falling under a high altitude smoke plume (see top image above).

In total, more than 7,800,000 acres have burned so far in the U.S. this year. This represents the second worst fire year on record so far compared to the last ten years and may ultimately beat out 2006 as the second worst fire year ever recorded. By end 2006, 9 million total acres had burned. During the worst fire year for the U.S. — 2015 — 11 million acres burned in total. By this time during 2015, nearly 9 million acres had been consumed compared to 2017’s present total near 8 million acres.

These fires are occurring primarily in the west where a persistent high amplitude ridge in the Jet Stream has formed. This ridge keeps enabling heatwaves to bake the region and spike fire dangers. And it’s a weather feature that some scientists are saying is linked to human-caused climate change — which is causing the Arctic to warm, while pulling meridional south-to-north upper level winds into the polar zone and producing a wavier jet stream during extreme weather patterns.

(A study produced by a team of scientists including Dr. Michael Mann in March linked extreme summer weather patterns to polar warming and a wavier jet stream.)

The net effect is to create a kind of Halo of Storms and Heatwaves over the middle and upper latitude regions of the world. Earlier this year, The Scientific American noted:

What we think happens is that when there is a ridge forming in a location where Arctic warming can intensify it, that makes the ridge strong and builds it even farther northward. It creates an even bigger wave in the jet stream. You get a stronger ridge over western North America and a stronger southward dip that is farther toward eastern North America.

A subsequent scientific study lead by Dr. Michael Mann and presented in March of this year found that:

… analysis of both historical model simulations and observational surface temperature data, strongly suggests that anthropogenic warming is impacting the zonal mean temperature profile in a manner conducive to wave resonance and a consequent increase in persistent weather extremes in the boreal summer.

And this is exactly what we’ve seen over the U.S. this summer. A stronger than normal ridge in the west fueling record heatwaves and wildfires and a stronger than normal trough in the east fueling more extreme storms. This is a pattern of juxtapposed extremes. One that appears to be fueled by climate change related factors.

Links:

NASA Worldview

National Interagency Fire Center

Largest Wildfire in Los Angeles History Burns Amid Record-Setting Heat

The Arctic is Getting Crazy

Extreme Weather Events Linked to Climate Change’s Influence on the Jet Stream

A Halo of Storms and Heatwaves

878 mb Storm Off North Florida — The Model Forecast for Irma that no one Wants to See Happen

As the United States struggles to recover from severe damage inflicted by one hurricane made far worse by climate change, another powerful storm is brewing over the hotter than normal waters of the tropical North Atlantic.

As of the 5 PM Atlantic Standard Time statement from the National Hurricane Center, Irma was positioned about 1,100 miles east of the Leeward Islands in the central tropical Atlantic. The storm hosted a small circulation, packing 110 mph winds and a minimum central pressure of 973 mb. Over the next few days, according to the Hurricane Center, Irma is presently expected to reach major hurricane status with 130 mph maximum sustained winds.

(Category 2 Irma in the Central Atlantic seems relatively innocuous. But NHC guidance indicates the potential for Irma to develop into a major hurricane over the next five days. Some of the longer range models, however, are producing some rather worrying forecasts. Image source: National Hurricane Center.)

The Hurricane Center is clear to note that it uncertain at this time if Irma will ultimately threaten the Bahamas or the mainland U.S. But the Center cautions that all interests remain watchful and prepared as the storm could pose a risk over the coming days:

It is much too early to determine what direct impacts Irma will have on the Bahamas and the continental United States. Regardless, everyone in hurricane-prone areas should ensure that they have their hurricane plan in place, as we are now near the peak of the season.

Looking beyond the official forecast, some of the our best long range model runs are putting together some seriously scary predictions for Irma. By next week, the Global Forecast System (GFS) model shows Irma as a 878 mb monster hurricane looming about 300 miles off Florida. 878 mb would represent the lowest pressures ever recorded in a hurricane in the Atlantic (The present strongest Atlantic storm was Wilma at 882 mb. The devastating Labor Day Hurricane hit 892 mb.). And it would almost certainly represent the strongest storm in our records ever to venture so far North. 878 mb roughly corresponds with maximum sustained winds in excess of 170 mph and possibly as high as 200 mph or more. And we’ve never seen something like that threatening the Central Atlantic U.S. East Coast in all of the modern era.

(A storm stronger than Wilma and approaching Tip’s record 870 mb intensity off North Florida and not in the Caribbean? GFS says it’s possible. Let’s hope for the sake of much that is precious and dear to us that this model forecast does not emerge. Image source: Tropical Tidbits.)

The model then slams the storm into Cape Hatteras just after midnight on Monday, September 11 as only a slightly weaker Category 5 range storm at 910 mb. The storm proceeds north into the Hampton Roads area early Monday morning retaining approximate Cat 5 status at 919 mb. After roaring over this highly populated low-lying region, the storm enters the Chesapeake Bay at 934 mb by noon on Monday — in the Category 4 range and still stronger than Hurricane Sandy — before crossing up the Bay and over the D.C. region by evening the same day at 958 mb (approx Cat 3).

To say this would be an absolute worst case disaster scenario for the Mid-Atlantic is an understatement. A storm of this intensity would produce 10-20 foot or higher storm surges, devastating winds, and catastrophic rainfall throughout the Outer Banks, Hampton Roads and on up the Chesapeake Bay. But unlike Harvey, it would be a fast-moving event. More like a freight train than a persistently worsening deluge.

This long range model scenario is not, however, an official forecast. It’s just what the GFS atmospheric computer models are presently spitting out. And such long range predictions from a single model, no matter how reliable, should be taken with at least a pinch of salt. That said, we should certainly, as the NHC recommends, keep our eyes on Irma and keep our response plans ready.

(Sea surface temperatures in the North Atlantic off the Southeast Coast are between 1 and 1.8 C above average. Atmospheric moisture levels are quite high as is instability. So as with Harvey, we have quite a lot more fuel than normal available for a hurricane to feed on. Image source: Earth Nullschool.)

We should also note the context in which this present extreme potential emerges. Ocean surfaces in the North Atlantic off Florida are very warm with temperatures around 30.5 degrees Celsius (87 F) near the Bahamas. This is about 1.8 degrees Celsius above the already warmer than normal climatological average. Atmospheric moisture and instability in this region of the North Atlantic are also quite high. These two conditions provide fuel for hurricanes that do enter this region. They are conditions that are linked, at least in part, to human-caused climate change. And they are similar to the conditions that amplified Harvey’s intensity just prior to landfall.

So though the GFS forecast described above is far from certain, we should absolutely listen to the NHC’s urging for us to pay attention to what could be another dangerous developing storm. One that appears to at least be physically capable of defying previous weather and climate expectations. Let’s just hope it doesn’t.

Links:

The National Hurricane Center

Earth Nullschool

Tropical Tidbits

List of Most Intense Tropical Cyclones

Major Environmental Groups Aim for 100 Percent Renewable Energy; Nature Study Shows Solar Alone is on Track Toward 50 Percent

Here we explore how models have consistently underestimated PV deployment and identify the reasons for underlying bias in models… We propose that with coordinated advances in multiple components of the energy system, PV could supply 30–50% of electricity in competitive markets.Nature

It’s the call for the rapid conversion of energy systems around the country to 100% renewable power — a call for running the United States (and the world) on sun, wind and water. What Medicare for All is to the healthcare debate, or Fight for $15 is to the battle against inequality, 100% Renewable is to the struggle for the planet’s future. — Bill McKibben

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Let’s be very clear. The big first step in saving cities like Houston and regions like South Asia from this global warming nightmare we’re creating is to replace the chief cause of the problem with something else. And when the central driver of global warming is fossil fuel burning, then you can’t solve that problem by continuing to dig up fossil carbon and combust it. Full stop.

(The world is heating up, primarily due to fossil fuel burning. Rapidly replacing those fuels with renewables is crucial going forward. Image source: NASA.)

That’s why visionaries like Bill McKibben and agencies like 350.org and the Sierra Club are now engaged in a campaign to promote 100 percent renewable energy policies at every level of government. Under such policies, an increasing number of these governments and institutions commit to using only renewable energy. And they do so within a prescribed timeframe.

It’s a policy aimed at solving the climate crisis while saving the stakeholders themselves. At not continuing along a path toward worse disasters than Harvey and ultimately lethal climates like those of the Permian. At not putting stakeholder cities, states and industries at ever increasing risk. Ultimately, it’s aimed at combating the central cause of global warming — fossil fuels — by leveraging the superior economics of wind and solar to crowd them out. A goal that’s enabled by the fundamental economic superiority of renewables. And the timing couldn’t be better.

For renewable energy, in the form of wind and solar, is now less expensive in most applications than gas and coal. And the price is continuing to drop. This means that the economic argument for fossil fuels has fewer and fewer legs to stand on. Arguments attacking renewables increasingly rely on either baseless and false inflations of environmental damage, or on a downplaying of renewable energy’s economic strength and potential future capacity — attempting to divide and conquer environmentalists by creating inaccurate impressions or to tamp down enthusiasm among renewable energy supporters. Such anti-factual messaging, however, reveals the present economic, political and social vulnerabilities of fossil fuel interests as they are forced more and more to rely on outright deception.

Now, as with climate change, the fossil fuel special interests are facing off against a rising tide of scientific evidence. This time, the science isn’t just revealing the causes of environmental harm in the form of fossil fuel burning — it is showing why renewable energy’s growth rate will be faster and more transformative than expected.

(Environmental organizations like Greenpeace have provided the most optimistic and accurate assessments of solar growth rates — flummoxing most energy industry experts. Image source: Nature.)

A new study in Nature this week found that solar energy alone would represent up to 50 percent of global electricity generation capacity by 2050 on the basis of its economic strength alone. Solar benefits from a simplicity of design, use of common materials, easy scalability, a proven track record of increasing efficiency over time, and the ability to easily loop in technological design breakthroughs. These advantages have allowed solar to reduce its price by 22 percent for each doubling of installed capacity.

Wind benefits from similar economies of scale. And a new study out from the National Renewable Energy Lab found that the price of wind would fall by another 50 percent through 2030. Estimates that are up from 30 percent even earlier this year. A pretty amazing ability considering the fact that wind is already the lowest cost energy source in many applications.

This economic strength really gives environmental advocacy groups an effective tool for achieving goals going forward. Now, a zero emitting technology that produces orders of magnitude less harm than present energy systems is within reach. Now cities, states and nations can change the world for the better. And now they can do it on the cheap. But not only does this thrust jibe with traditional environmental goals — it appeals to the 72 percent of republicans who support renewable energy, regardless of their views on climate change. In this way, the 100 percent renewable campaign is one that appeals to all Americans and can therefore gain ground in pretty much every state and region.

RELATED STATEMENTS AND INFORMATION:

Links:

The Underestimated Potential of Solar Energy to Mitigate Climate Change

Wind Power Costs Could Drop 50 Percent. Solar PV Could Provide up to 50 Percent Global Power. Damn.

Innovation Can Reduce Wind Energy Costs by Another 50 Percent Through 2030

Bill McKibben Kicks Off Keep it 100 Campaign

 

Half a World Away From Harvey, Global Warming Fueled Deluges Now Impact 42 Million People

Rising sea surface temperatures in South Asia led to more moisture in the atmosphere, providing this year’s monsoon with its ammunition for torrential rainfall. — The Pacific Standard

While flooding is common in the region, climate change has spurred dramatic weather patterns, greatly exacerbating the damage. As sea temperatures warm, moisture increases, a dynamic also at play in the record-setting rainfall in Texas. — Think Progress

******

With Harvey delivering its own hammer blow of worst-ever-seen rainfall to Texas, 42 million people are now impacted by record flooding half a world away. The one thing that links these two disparate disasters? Climate Change.

A Worsening Flood Disaster in South Asia

As Harvey was setting its sights on the Texas Coast this time last week, another major rainfall disaster was already ongoing. Thousands of miles away, South Asia was experiencing historic flooding that seven days ago had impacted 24 million people.

At the time, two tropical weather systems were developing over a very warm Pacific. They were angling in toward a considerably pumped up monsoonal moisture flow. And they appeared bound and determined to unleash yet more misery on an already suffering region.

As of Monday, the remnants of tropical cyclone Hato had entered the monsoonal flow and was unleashing its heavy rains upon Nepal. The most recent in a long chain of systems that just keeps looping more storms in over the region to disgorge they water loads on submerged lands.

By Wednesday, the number of people suffering from flooding in India, Bangladesh and Nepal had jumped by 18 million in just one week to more than 42 million. With 32 million impacted in India, 8.6 million in Bangladesh, and 1.7 million in Nepal. More tragically, 1,200 people have perished due to both landslides and floods as thousands of square miles have been submerged and whole regions have been crippled with roads, bridges, and airports washing out. Adding to this harsh toll are an estimated 3.5 million homes that have been damaged or destroyed in Bangladesh alone.

Worst impacts are likely to focus on Bangladesh which is down-stream of flooded regions in Nepal and India. As of last week, 1/3 of this low-lying country had been submerged by rising water. With intense rains persisting during recent days, this coverage is likely to have expanded.

Hundreds of thousands of people have now funneled into the country’s growing disaster shelters. A massive international aid effort is underway as food and water supplies are cut off and fears of disease are growing. The international Red Cross and Red Crescent and other relief agencies have deployed over 2,000 medical teams to the region. Meanwhile, calls for increased assistance are growing.

Warmer Oceans Fuel Tropical Climate Extremes

As with Harvey, this year’s South Asia floods have been fueled by much warmer than normal ocean surface temperatures. These warmer than normal ocean surfaces are evaporating copious amounts of moisture into the tropical atmosphere. This moisture, in turn, is intensifying the monsoonal rains.

(Very warm ocean surface temperatures related to global warming are contributing to catastrophic South Asian flooding in which 42 million people are now impacted. Image source: Earth Nullschool.)

In the Bay of Bengal, ocean surfaces have recently hit about 3 C above the three decade average. But ocean waters have been warming now for more than a Century following the initiation of widespread fossil fuel burning. So even the present baseline is above 20th Century temperature norms. At this point, such high levels of ocean heat are clearly having an impact on tropical weather.

In an interview with CNN, Reaz Ahmed, the director-general of Bangladesh’s Department of Disaster Management noted last week that:

“This is not normal. Floods this year were bigger and more intense than the previous years.”

Further exacerbating the situation is that fact that glaciers are melting and temperatures are rising in the Himalayas. This increases water flow into rivers during monsoon season even as glacial melt flow into rivers is reduced during the dry season. It’s kind of a flood-drought whammy in which the dry season is growing hotter and drier for places like India, but the wet season is conversely getting pushed toward worsening flood extremes.

Links:

The Pacific Standard

Think Progress

Earth Nullschool

Nepal, India, Bangladesh Floods Impact Millions

NASA Worldview

Hat tip to Colorado Bob

So Let’s Talk About the Science of How Climate Change Kicked Harvey into Higher Gear

Harvey is finally on the move.

After making a second landfall early Wednesday, the storm is passing slowly out of the East Texas region that has suffered so much first from Harvey’s initial lashing as a rapidly intensifying category 4 storm, and second from its long-lasting and unprecedented rainfall.

(Harvey rapidly intensifies into a category 4 monster just prior to landfall. This rapid intensification and other climate change related factors helped to make Harvey a more dangerous storm. Image source: NASA.)

At this point we can take a bit of a step back to look at the larger situation. Sure, impacts will probably continue and even worsen for some areas. And due to a historic pulse of water heading downstream, the hammered city of Houston is far from out of the woods.

But as with Sandy and so many other freakish strong storms in a present climate that has warmed by around 1.2 C above pre-industrial values, we would be remiss if we didn’t discuss the climate change related factors that gave Harvey more fuel, that helped it to rapidly intensify, that worsened its flooding — both from rains and from storm surge, and that may have helped to produce a still pocket in the upper level winds that allowed it to stick around for so long.

Warmer Ocean Surfaces Mean More Rapidly Intensifying Storms, Higher Peak Intensity of Worst Storms

Hurricanes like Harvey cannot readily form in cool waters below a range between 70 and 75 degrees Fahrenheit. Ideally, the storms require ocean surface temperatures warmer than 80 degrees (F). And the more heat that’s available at the ocean surface, the more energy that’s available for a storm when it does form.

This energy comes in the form of atmospheric lift. In other words, air rises off the water more vigorously as water temperature rises. This lifting energy is called convection. And the more that’s available, the more powerful storms can ultimately become.

(Sea surface temperatures were between 1 and 2 degrees Celsius above average as Harvey approached Texas. Human-forced climate change is causing the oceans to warm. This, in turn, provides more fuel for hurricanes like Harvey — helping them to rapidly intensify and pushing their peak strength higher. Image source: NOAA.)

According to Dr Michael Mann, Ocean surfaces in the Gulf of Mexico are fully 1 to 1.5 degrees Celsius warmer, on average, than they were just 30 years ago. This warming provides more energy for storms that do form. And this, in turn, raises the top potential intensity of storms.

Some scientists, like Dr. James Hansen, refer to this prevalence of worsening extremity as loading the climate dice. If, in the past, we were rolling with a die six with a 1 representing the lowest storm intensity and a 6 representing the highest, we’re now rolling with something like a die six +1. The result is that the strongest storms are stronger and the absolutely strongest storms have an ability to achieve previously unattainable strengths due to the fact that there’s a lot more energy there to kick them into a higher state.

Increased potential peak storm intensity as a climate change factor does not necessarily result in more tropical storms forming overall. That part of the science on hurricanes is highly uncertain. But that heat engine in the form of warmer surface waters is available for the storms that do form to tap. And that can make them a lot stronger and more damaging than they otherwise would have been.

(Loading the climate dice — changes in frequency of cold and warm temperatures also has an impact on heatwaves, droughts, wildfires, storm intensity, and heavy precipitation events. Image source: NASA.)

As Harvey approached land, it tapped the energy of this much warmer than normal ocean surface. And that energy caused the storm to rapidly strengthen — first from a minimal tropical storm to a Hurricane, and then from a minimal hurricane to a Category 4 monster. Meteorologists tend to call such periods of rapid intensification — bombification. This term comes from minimum pressures that rapidly drop in swiftly strengthening storms — seeming to bomb out. And due to warming, the science indicates that rapid strengthening is also more likely. With some models pointing toward a 10-20 fold increase in the frequency of rapidly intensifying storms by the end of this Century if human forced warming of ocean surfaces continues.

Warmer Atmosphere Means Heavier Rainfall

Related to a warming of the ocean surface (and land surfaces as well) is the basic scientific fact that such warming causes the amount of water vapor in the atmosphere to increase. In total, with each 1 degree Celsius of warming near the Earth’s surface, the atmosphere ends up holding about 6-7 percent more moisture. The properties of this warming-driven increase in atmospheric moisture are described by the scientifically proven Clausius–Clapeyron relation which defines, in meteorology, how atmospheric water vapor content is driven by various factors, including temperature.

If we dig just a little bit further into our understanding of how this scientific driver impacts the atmosphere in a warmer world, we find that not only does the moisture content of a warmer atmosphere increase, but both the rates of evaporation and precipitation increase.

 

(Global warming has brought with it a sharp increase in the number of record-breaking daily rainfall events. This is due to the fact that a warmer world holds more storm-fueling moisture in its atmosphere. This warmer, wetter atmosphere increased the peak potential rainfall from Harvey enabling it to smash records for rainfall rates and precipitation totals. Image source: Increased Record-Breaking Precipitation Events Under Global Warming.)

It is here that we return to the loaded climate dice mentioned above. If, as we find today, the Earth is about 1.2 degrees Celsius warmer than in the past, then the atmosphere holds more moisture. About 7-8 percent more. And since there’s more heat, evaporation is more intense where it does happen. This loads the climate dice for more intense droughts. But since what goes up in the form of evaporation results in a heavier load of moisture in the higher clouds and in the storms that do form, the rains that follow will also tend to be more intense. This loads the dice for more severe rainfall events. And we have a very clear scientific observation that the most extreme rainstorms are becoming much more intense overall (see above graphic).

For Harvey, this meant that more moisture was available to provide the record-setting rainfall amounts coming from that system. Peak rainfall totals from the storm are now at nearly 52 inches. This is the most rainfall ever to occur in Texas from a tropical system in our records. A measure that may also break the all-time U.S. record for rainfall from a tropical storm. And Harvey was enabled to produce such high rainfall amounts by a warmer atmosphere.

Harvey a Brown Ocean Cyclone?

Increasing rates of evaporation and precipitation had one obvious effect in Harvey — they increased the potential severity of rains coming from this kind of storm. But they also increase the ability of storms like Harvey to maintain strength or even intensify over land. If, for example, a storm like Harvey dumps a very heavy load of rainfall over land and if the evaporation from these recent rains has increased in a warming world, then storms like Harvey can tend to draw strength back from what amounts to a small ocean on land.

A recent NASA scientific paper on this issue describes a Brown Ocean effect. The 2013 NASA paper noted:

Before making landfall, tropical storms gather power from the warm waters of the ocean. Storms in the newly defined category derive their energy instead from the evaporation of abundant soil moisture – a phenomenon that Andersen and Shepherd call the “brown ocean.”

…The research also points to possible implications for storms’ response to climate change. “As dry areas get drier and wet areas get wetter, are you priming the soil to get more frequent inland tropical cyclone intensification?” asked Shepherd.

In essence, cyclones are better able to maintain strength or even re-intensify over wet areas of land in a warmer world due to increasing levels of evaporation and it was Harvey’s ability to maintain tropical storm strength over land for up to three days that helped to enable it to keep dropping such heavy volumes of rain.

Higher Seas Mean Worse Storm Surge Flooding

A warmer climate also brings with it the melt of continental glaciers and the thermal expansion of ocean waters. As glaciers flood into the world’s oceans, they rise. And since fossil fuel burning began at the start of the industrial age this related warming of the Earth and melting of glaciers has caused the oceans around the world to rise by more than 20 centimeters globally.

(Global warming increases the base ocean level which, in turn, worsens storm surge flooding. Harvey’s storm surge came in on this higher ramp. Image source: Sea Level Rise Science.)

Such higher seas alone are causing some coastal settlements to flood even on sunny days. But when storms like Harvey come roaring ashore, they do so on a higher overall launching pad. And this produces a multiplier effect for storm surge damages. A multiplier that would not have been there if the world hadn’t warmed.

Polar Warming Contributes to Blocking Patterns That Make Weather Stick Around in One Place Longer

Another climate change related factor that contributed to Harvey’s danger was its persist hovering over the same region. Harvey would not have been as damaging for Texas and the Gulf if it hadn’t hung over East Texas for more than five days. But here, again, we find that climate change related factors appear to be contributing to the increased lingering of various extreme weather producing systems.

To understand how, we need to look at the upper level atmospheric circulation pattern that moves weather systems from place-to-place. In other words — the Jet Stream. Climate change influences the Jet Stream by generating more warming at the poles than near the Equator. This in turn, according to the research of scientists like Dr Jennifer Francis, changes atmospheric slope. Warmer poles, in other words, create a taller atmosphere at the poles relative to the Equator.

(A high amplitude ridge-trough pattern helped to create a stagnant upper air slot in which Harvey stalled. This voiding of upper level steering currents enabled Harvey’s persistence. Some scientists are pointing toward increasing prevalence of these kinds of high amplitude ridges and troughs related to polar warming warming which is an upshot of global warming. Image source: Earth Nullschool.)

Since atmospheric slope and temperature differences between the poles and Equator drive the speed of the Jet Stream, warmer poles cause the Jet Stream to slow down and meander. This generates big ridges and deep troughs. It also appears to assist the generation of large blocking high pressure systems. And all of these features can tend to cause weather patterns to get stuck.

This year, a persistent trough in the Eastern U.S. has generated a consistent stormy pattern and aided in the firing of powerful thunderstorms that produced record rains over places like Kansas City, Missouri. In the West, a persistent ridge has produced record heat and very extreme wildfires while aiding the formation of a very intense flash drought in Montana and the Dakotas. Harvey got stuck in a stagnant pocket between these two relatively fixed weather patterns. A climate change related feature that may have increased the duration of Harvey and facilitated its record rains falling over such a long period.

Other Factors — Interaction With The Eastern Trough

Finally, we can state that Harvey’s interaction with the very deep eastern trough also helped to fuel it. The trough provided a moisture and instability kick to Harvey as it moved over Texas — helping to wring out tropical moisture over the Lone Star State. And if we accept the fact that polar warming contributed to the depth of this eastern trough by slowing down the Jet Stream, then its interaction with Harvey was also a climate change related factor.

Qualifying This Discussion

What can be said with certainty is that climate change did not cause the hurricane. That hurricanes do happen in a normal climate. But this is the same same thing as saying that home runs happen in both middle school and major league baseball. It’s all baseball, but the factors from one to the other have qualitatively changed in an obvious fashion. The same thing happens to weather in a warming world. And it is due to the changes in these underlying factors that we can say without a doubt that climate change made Harvey worse.

What we can also say is that our certainty of all these various climate change related factors involved varies. For example, we can say with very high certainty that global warming is worsening rainfall extremes and that sea level rise is worsening storm surges. We can say with a good level of confidence that the peak intensity of the worst storms is also increasing and that bombification is more likely. And we can say with moderate confidence that climate change is altering atmospheric circulation patterns (an issue that is still under considerable debate).

But the varying degrees of certainty with regards to these aspects do not change basic facts. Your climate is your weather averaged over 30 years. And if the world warms, both your climate and your weather change.

Harvey Intensifies Slightly Just Prior to Second Landfall

Tropical Storm Harvey, which has dumped more than 51 inches of rain over parts of Texas and flooded hundreds of thousands of homes, intensified this afternoon over the Gulf of Mexico as it continued to move to the North-Northeast.

(Visible satellite imagery of Tropical Storm Harvey late afternoon on August 29th shows the storm slightly re-intensifying before a second landfall with strong rain bands again threatening Houston. Image source: The National Hurricane Center.)

As of the 4 PM CDT advisory from the National Hurricane Center, Harvey’s minimum central pressure had dropped to 994 mb even as its maximum sustained winds increased to 50 mph. This made Harvey a still rather weak tropical storm is it continued to lash sections of Eastern Texas and Louisiana with winds and rains.

Now a 5-day long event since threatening the Texas Coast as a category 4 storm on Thursday, Harvey has produced the worst flooding in Texas state history. In Houston, dams designed to contain a 1,000 year flood are overflowing — increasing already catastrophic flooding throughout the beleaguered city.

(After a brief respite, Houston’s eastern suburbs are again seeing heavy rain from Harvey. Image source: National Weather Service.)

Very heavy rains have fallen over Houston since Saturday. But during the early afternoon hours rains had lightened over the city as the heaviest squalls shifted further east over Beaumont. Recent weather radar imagery from the National Weather Service, however, has shown more intense rain bands again back-filling over Eastern Houston in coordination with Harvey’s recent re-intensification.

Tonight, Harvey is expected to track inland before being pulled northward by a trough and finally leaving Southeastern Texas behind. But not before giving the region one last lashing over the next 12-24 hours or so while dumping another 6-12 inches of rain.

RELATED STATEMENTS AND INFORMATION:

Links:

The National Hurricane Center

National Weather Service

Worst Tropical Rainfall Event in Texas History

Worst Tropical Rainfall Event in Texas History Made More Deadly by Climate Change: Harvey Totals Now Top 49 Inches

We can’t say that Hurricane Harvey was caused by climate change. But it was certainly worsened by it. — Dr. Michael Mann

Harvey is already the worst rainstorm in U.S. history and it’s still raining.Meteorologist Eric Holthaus

******

It’s the fifth day of an unprecedented rain event that one of the world’s top scientists is saying was made worse by climate change. Flood totals as of earlier this morning topped a record-smashing 49 inches. Emergency management officials are saying that this is a 1,000 year flood event (and it could get worse). And the rains are still falling as levees in and around the city of Houston over-top or fail.

If peak rainfall was the whole of this story, then things wouldn’t be quite so bad for Houston and other Texas cities. But with this particularly severe storm it’s a combination of size, severity and duration that has produced such terrible floods. Harvey’s persistent stall has brought very severe rains to a large swath running all the way from southeast Texas in an arc through Mississippi. And a huge flood basin from Victoria to Austin to Lufkin to Lake Charles has now received between 8 and nearly 50 inches of rain as of early Tuesday.

Such a large swath has resulted in a more significant pulse of waters flooding into streams, lakes, and reservoirs. This depth of zonal flooding generates more water pile ups as flows move downstream. Resulting in higher peaks at rivers in places like Houston and putting more stress on water management infrastructure. An infrastructure that was designed to handle the 100 to 1,000 year floods of a gentler climate but not the so-called 1,000 year or worse floods of an atmosphere loaded up with a much greater portion of storm-fueling heat and moisture.

That this will be the worst flood in Texas history by a number of measures goes without question. That the flood was made worse by climate change is a scientific fact. That Texas is still getting pummeled by a tragic blow that is costing both lives and tens of billions of dollars in damages is a foregone conclusion.

At this point, the question we need to be asking ourselves is how can we prepare for more of these kinds of extreme rainfall events — which are surely coming. And how can we honestly work together to reduce both their future intensity and damage? How can we ultimately protect lives and property in a world we have made more dangerous by burning fossil fuels and dumping carbon into the atmosphere? And how quickly can we resolve ourselves to stop making the problem worse?

UPDATED (1)

RELATED STATEMENTS AND INFORMATION:

Links:

Hurricane Harvey Made More Deadly by Climate Change

National Weather Service Houston

The Capital Weather Gang

Harvey is Already the Worst Rainstorm in U.S. History and it’s Still Raining

Houston Levee Failures

 

Houston Levee Failures: Reports Indicate that Reservoirs are Being Strained Past the Spillover Point

DEVELOPING STORY:

News reports Monday night from Houston KTRK indicated that water levels at Addicks and Barker Reservoirs were continuing to rise sharply despite controlled releases starting at 1 AM on Monday. According to these reports, the reservoirs had received upwards of 25 inches of rainfall. The National Weather Service indicated that another 25 inches may be on the way in total. And despite the controlled release, reservoir levels were continuing to rise at a rate of 4 inches per hour.

(Addicks and Barker Reservoirs spill into Buffalo Bayou, which then flows into downtown Houston. Earlier today controlled releases were begun in an attempt to slow water rise in the reservoirs. This release is failing to prevent rapid water rise within and around these reservoirs. Movement of flood waters into the reservoirs is pushing waters into subdivisions near the reservoirs even as risk of levee failure is rising. Image source: Harris County Flood Control District and Weather Underground.)

Such unprecedented rainfall totals caused city officials to warn that: “This event has the potential to exceed a 1,000 year flood plain threshold.” It’s worth noting that the Levees in Fort Bend County were designed only to manage a 100 year flood event and that the expected 59 foot crest of the Brazos River represented an 800 year flood event.

But by evening, very heavy thunderstorms were running in to Houston across Galveston Bay. These storms again pummeled the city with extraordinary rainfall amounts — pushing flood thresholds still higher.

As a result, concern about the communities surrounding these reservoirs is hitting a fever pitch. Flooding is now expected in all of the 41 city subdivisions surrounding Barker and also in all of the 52 subdivisions surrounding Addicks. In addition, three other neighborhoods could see flooding if water flanks the Addicks spillway.

More concerning, however, is this statement from KTRK:

In addition to these neighborhoods, officials have called for a mandatory evacuation of Inverness Forest on Cypress Creek and Northwood Pines on Spring Creek as a result of potential levee failures.

Throughout the day, there have been numerous indications that these reservoirs were under serious stress as more and more water rushed downstream. As of late afternoon, water levels had risen to 105 feet in the Addicks reservoir. And observers of various levees at the time had already noted that water was near overtopping in some places. This tweet from Jeff Linder shows water very close to the top of the Inverness Levee.

By evening, Addicks had topped 106 feet and Barker was at 101 feet with the water still rapidly rising. Meanwhile, a dam upstream in Brazos County burst at 9 PM — further adding to the torrent heading toward Houston. With imminent danger of worse floods approaching, the National Weather Service subsequently issued a very clear warning that residents in the impacted neighborhoods should evacuate before 11 PM (CDT) or risk being stranded. Such a clear warning was an indication that disaster officials expected a high risk that at least some of the impacted levees would be breached or spill over.

Uncontrolled Releases and Failures Begin Tuesday Morning

By Tuesday morning, reports were coming in that the Addicks reservoir had topped 108 feet and that parts of the dam section of that reservoir near Buffalo Bayou was flowing out through the emergency spillway. This spillover is adding more water to Buffalo Bayou — a main river running through Houston and a significant source of flooding thus far. The Addicks Dam, as of 11 AM CDT remained structurally sound and the main issue with the levee at that time was due to uncontrolled spill out through the emergency spillway. As of early Tuesday, officials expected levels at Addicks Dam to peak at more than 110 feet this week. Risk of dam breakage at this time, according to officials, is said to remain low.

Officials, as of late Tuesday morning, were increasingly concerned about a Barker Dam overflow due to rising waters in the Barker reservoir as well. Water gauges at Barker had been put out of commission by the rising waters as of last night. So it is difficult to clarify the situation at the Barker Dam at this time. However, Barker is expected to exceed the 101 foot level in which uncontrolled overflow occurs, ultimately peaking at 104 feet. As with Addick, Barker Dam presently remains structurally sound with no major risk of imminent breakage, according to officials.

Meanwhile, a levee failure has been reported Tuesday morning in Brazoria County, south of Houston, at Columbia Lakes. Emergency officials in the area were very concerned about residents sheltering in their homes in this region — urging all Columbia Lakes residents to “get out!”

(UPDATED — UPDATES TO FOLLOW)

RELATED REPORTS AND INFORMATION:

Links:

Addicks Dam Begins Overflowing

KTRK

KBXT

Harris County Flood Control District

Weather Underground

Hat tip to wili

Hat tip to eleggua

Hat tip to Andy in San Diego

With up to 42 Inches of Rain Already Dumped on Texas, Harvey’s Track Over Gulf Means 10-21 More to Come

By mid-afternoon Monday, a still very wet Harvey had back-tracked over the Gulf of Mexico. The storm has now dumped unprecedented, record-setting rains totaling more than 30 inches over a Houston that is being forced to release dam water into already flooded regions in order to prevent over-topping or worse. Meanwhile, nearby Dayton, as of this morning, had received nearly 40 inches since the storm began on Friday. And as of noon, Baytown, TX has seen 41.77 inches over the sixty hour storm period.

Harvey’s circulation is now located along the coast south and west of Galveston and it is edging slowly back over the Gulf of Mexico. The storm is still drawing copious volumes of moisture up from the Gulf. This moisture flood is still fueling a massive shield of rain and thunderstorms stretching over much of Eastern Texas, a good portion of Louisiana and parts of Mississippi. And with its center now moving back over water, this moisture flow and its related thunderstorms are again starting to intensify.

 

(Harvey’s rains shield reinvigorates as the storm once again crosses into the Gulf. Image source: The National Weather Service.)

Presently, the most intense rains from the system are clustered over Houston (still), adjacent portions of the Texas Coast, and Eastern Louisiana.

As of 4 PM CDT, Harvey had re-intensified somewhat to 997 mb with maximum sustained winds near 45 miles per hour. Over the next 24 hours, Harvey is expected to back slowly southward over the Gulf of Mexico, then turn back northward. By late Tuesday, the tropical storm is again expected to be closing in on the Texas Coast for a likely second landfall late Tuesday or early Wednesday.

Present satellite imagery shows Harvey reintensifying somewhat in the infrared — with stronger storms firing near Harvey’s Center and just to the north in the Houston region. A dry slot of air in the storm, however, is likely to limit re-strengthening as the storm passes over water during the next 12-24 hours.

(Harvey appears to restrengthen somewhat in the infrared satellite as it taps Gulf heat and moisture. Image source: The National Hurricane Center.)

As such, Harvey at present is still a rather dangerous rain event. An event that is now re-gathering some of its strength and intensity as it digs more deeply into Gulf moisture.

Earlier today, meteorologists noted an optimistic wedge of dry air moving into the system from Central Texas. Such a wedge would tend to tamp down rainfall rates over Houston and East Texas. And the region did get a bit of a respite from heavy rains earlier in the day. However, with the moisture tap to that abnormally warm Gulf now re-established, heavier rains are again filling in near the storm center and just to the north.

(NOAA is still showing a potential for in excess of 20 inches of rain in the Houston region even following the massive, historic deluge that has already been unleashed by a hurricane fueled by a record warm world. Image source: NOAA.)

As a result, Houston is likely to get socked with a third bout of very heavy rain tonight through tomorrow with a fourth bout likely on tap for late Tuesday night. And, presently, NOAA now predicts that up to another 21 inches of rain is on the way for the Houston region on top of the already historic totals of 20-40 inches that have inundated the city.

(UPDATED 7)

UPDATE (8): The latest advisory from the National Hurricane Center notes that:

Harvey is expected to produce additional rainfall accumulations of 10 to 20 inches through Thursday over parts of the upper Texas coast into southwestern Louisiana. Isolated storm totals may reach 50 inches over the upper Texas coast, including the Houston/Galveston metropolitan area. These rains are currently producing catastrophic and life-threatening flooding over large portions of southeastern Texas. DO NOT ATTEMPT TO TRAVEL IN THE AFFECTED AREA IF YOU ARE IN A SAFE PLACE. DO NOT DRIVE INTO FLOODED ROADWAYS. Please see warnings and products issued by your local National Weather Service office for additional information on this life-threatening situation.

This storm isn’t over folks. Not by a long shot.

RELATED INFORMATION AND STATEMENTS:

Links:

The National Weather Service

The National Hurricane Center

NOAA

Harvey Moves Back Over Water. Historic Rainfall Will Continue.

Hat tip to wili

Hat tip to eleggua

Nearing a Trillion Watts: By End 2017, Global Wind + Solar Capacity Will be 2.4 Times That of Nuclear

In 2017, the world will add about 80 gigawatts of new solar capacity. It will also add another 60 gigawatts of new wind capacity. This combined 140 gigawatts will push wind and solar to 940 gigawatts of global capacity — or nearly one trillion watts. A pace that’s ahead of even recent optimistic projections by about 25 gigawatts:

(Historic and projected global wind and solar capacity. Image source: Forecast International.)

Such a total renewable energy generation capability compares to a global 391.5 gigawatts of nuclear energy now in use around the world. In other words, solar energy by end 2017 will come close to surpassing total global nuclear energy capacity. And wind and solar combined will account for 2.4 times the amount of installed nuclear around the world.

The reason wind and solar are now rapidly eclipsing global nuclear capacity is due to simple economic competitiveness alone. By 2022, wind + solar is now expected to exceed 1,600 gigawatts. Or more than 4 times present nuclear capacity. Such a strong build rate comes on the back of rapidly falling costs for renewable energy systems. With wind and solar’s levelized costs of production now below that of all other new power sources in many places and with prices bound to continue falling through 2030, base economic incentives for adding renewable energy are now quite high. Add in the fact that these systems produce no harmful particulate or greenhouse gas pollution in use, and the appeal of such clean energy systems is difficult to contest.

(In the U.S. unsubsidized levelized costs of energy vastly favor wind and utility scale solar. And indication that other utility sources such as coal and gas are over subsidized by society. Image source: Clean Technica.)

Increasingly, coal and even gas fired power generation relies on subsidies and an uneven playing field to compete with renewable energy systems. With research from John Abraham indicating that from 2013 to 2015, global fossil fuel subsidies rose from a staggering 4.9 trillion dollars to an astounding 5.3 trillion dollars. And backwards-looking political bodies like the Trump Administration are increasing this highly distorting and harmful subsidy allotment still further.

There’s really no excuse for such an unequal and continuously tilting playing field considering the fact that fossil fuels are the main driver of a climate change that is contributing to catastrophic storms like Harvey and a rising ocean that is now threatening hundreds of cities around the globe. Considering the fact that about 7 million people die each year from air pollution primarily related to fossil fuel burning each year alone. With inexpensive and much cleaner alternatives now available, and with these alternatives proving increasingly competitive with the rickety and harmful old energy sources that the world’s tax payers unjustly prop up, there’s really no excuse in creating further delays for the far less dangerous and harmful clean energy systems we all deserve.

Links:

Forecast International

Clean Technica

Global Solar Capacity Set to Surpass Nuclear

Wind Energy Cost Reductions of 50 Percent Possible by 2030

Global Wind Energy Insight

Global Cumulative Installed Wind Capacity

7 Million Premature Deaths Annually Linked to Air Pollution

Trump Moves to Increase Subsidy for Coal on Federal Lands

 

Harvey’s Flooding Already Catastrophic and Another 2-3 Feet of Rainfall is on the Way

For Houston, a city that hosts a massive oil industry, it’s the climate change related flood version of the Fort McMurray fire. And we may well be witnessing, at this time, a tragedy that we could have at least in part prevented, but didn’t.

*****

Last week at this time, meteorologists were tracking a tropical cyclone moving across the Caribbean. 5-7 day models indicated that the system would enter the Gulf of Mexico by late week. This Gulf was hotter than normal. And for the past three months it had been dumping an over-abundance of moisture into an unusually deep summer trough over the Eastern U.S. This interaction between two features related to human-forced climate change was already producing very severe thunderstorms that generated record rainfall over places like Kansas City, Missouri.

Harvey was very moisture rich. It issued from a tropical convergence zone and monsoon cycle that had hit unusually high intensity — due, at least in part, to abnormally warm ocean surface waters injecting much higher than normal moisture loads into the tropical atmosphere. And early last week there was some serious concern that intense tropical moisture in the form of Harvey could combine with a Gulf and Eastern U.S. weather and climate pattern that had already produced unprecedented rains to generate ultimately catastrophic results.

These fears have now been realized.

As of this afternoon,  parts of Houston and Southeast Texas had received more than 30 inches of rainfall — with up to 26 inches falling in just one 24-hour-period. Hourly rainfall rates at times have hit an equally unprecedented rate of up to six inches per hour. For context, one inch per hour rainfall rates in the past have been considered extreme. Six inches per hour is just off the charts. In many places, the most rain ever to fall over a one day time-frame was breached.

As we have seen so often around the world from globally increasing instances of record rainfall, roads flooded, cars were abandoned, and people were forced to climb onto their rooftops to flee the rising waters. In a Houston that is increasingly looking like post-Katrina New Orleans, more than 1,000 emergency calls for water rescues had been received by this morning. And with rivers hitting never-before-seen heights in a flood-prone city that is also facing the effect of rising sea levels, the rains were showing little sign of abating.

(Pivotal weather shows up to 32 inches of additional rainfall for the Houston region through Tuesday. The storm, however, may last through Thursday or later. Image source: Pivotal Weather.)

As much as 1-3 feet of additional rain is still expected from the storm. In the worst case, this would bring ultimate rainfall totals to 50-60+ inches. In a litany that we are hearing practically everywhere now — this would be the worst rainfall event Texas has ever seen in our records. It might, ultimately, be the worst flood from rainfall the U.S. has ever seen.

Moreover, weather models now indicate that Harvey may slowly track back toward the Gulf of Mexico. If this happens, a storm that is already pulling severe volumes of moisture in from the Gulf could be somewhat re-invigorated. Such a result would bring a second pulse of intense rains to parts of Southeast Texas and possibly Louisiana.

(September 1 GFS model shows remnants of Harvey interacting with a tropical cyclone south of Baja to continue to pull rains over Texas and Louisiana. Image source: Earth Nullschool.)

An additional concern is the fact that later this week Harvey shows a possible interaction with another stationary tropical cyclone forming near the southern tip of Baja in the Pacific. The two storms appear to interact to draw still more moisture from the abnormally warm Gulf over Southeast Texas later this week. Of course, this GFS-based forecast is still longer range — and therefore less certain. But the models do seem to continue to indicate a persistent heavy rainfall potential for an already catastrophically flooded region over an unprecedented long time frame.

This is exactly the kind of extreme rainfall event that some of us have feared coming from a warmer, more moisture-rich atmosphere in which weather systems have tended, more and more often, to persist and produce long-lasting effects. For the sake of all involved, we are now reduced to prayers and hopes that the worst case does not continue to be realized.

(UPDATED 9)

RELATED REPORTS AND STATEMENTS:

Links:

The National Weather Service

The National Hurricane Center

Harvey has Unloaded 9 Trillion Gallons of Water

Catastrophic Flooding Beyond Anything Experienced in Houston

Global Number of Record-Breaking Daily Rainfall Events

Harvey’s Approach Brings Potential Severe 5-Day Rainfall Event for Texas and Louisiana

Pivotal Weather

Earth Nullschool

Hat tip to Greg

Hat tip to eleggua

Not time to Let Our Guard Down With Harvey; Rainstorm Expected to Last 5-9 More Days

As of early afternoon on Saturday Harvey was about to be downgraded to a strong tropical storm after slamming into the Texas coast as a Category 4 monster hurricane packing 130 mph sustained winds. Residents along the coast are just now starting to assess the initial damage from this first major blow. However, the big rain event that is Harvey is just now getting started.

(Harvey’s rains expand over Eastern Texas at 245 PM EST. Image source: National Weather Service.)

According to the National Hurricane Center, the storm’s forward speed has now slowed down to about 2 miles per hour in a north-bound direction. Meanwhile, its shield of encircling rains is expanding to cover most of eastern Texas. These rains are very intense — producing accumulations of more than 1 inch per hour in many locations. And with Harvey stalling out, such heavy rains are expected to persist over basically the same region and at a similar high intensity for at least the next four days. After that time, Harvey is expected to persist and rains of lighter, but still flood-producing force, may continue to fall over parts of Texas for up to five more days.

(Harvey has already dumped nearly 15 inches of rain on some locations. Despite this fact, NOAA is still predicting more than 20 inches of additional rain. Some models are indicating that final totals could range from 40-60 inches in some locations after a 6-10 day rain event. Image source: NOAA.)

It’s worth noting that though up to 15 inches of rain have already fallen from Harvey, the longer range models still show in excess of another 20 inches coming from the storm over the next week. Many models indicate that more than 40 inches of rain could fall in total. And some of our best models yesterday indicated a potential for up to 60 inches in some locations by the time all is said and done.

In other words, this storm is far from over. The main event, in which Harvey may ultimately produce historic rainfall totals, is just getting ramped up. So now is not the time to relax our guard.

(UPDATED 1)

Links:

See Notes on Climate Change’s Influence on Harvey Here

The National Hurricane Center

National Weather Service

NOAA

Rainfall Rising Nearing 15 Inches in Some Locations

Global Forecast System Model Reanalysis

Harvey’s Mammoth Deluge Potential: Some Models Are Showing Storm Could Produce Five Feet of Rain

Media, Texas, and Gulf Coast residents take note: the thing to be most concerned about with regards to Harvey is not its admittedly life-threatening storm surge and strong winds, but what is shaping up to be a potentially historic rainfall event.

*****

The latest update from the National Hurricane Center shows that Harvey continues to strengthen and is now a category 4 storm. Packing 130 mph winds and a 941 mb minimum central pressure, the storm is certainly now very powerful. This new intensity is above the NHC’s previously expected peak strength for the storm just prior to landfall late tonight. The situation is thus becoming ever more dangerous.

But with Harvey, the serious concern we are facing is not just the usual and notably very dangerous high winds and storm surge flooding that go along with a category 4 storm. We are also looking at very severe and long lasting flooding rains that will have the potential to cause damage and disruption for not just months but for years to come.

A Devastating Rainfall Potential

(Southeast Texas has never seen 60 inches of rainfall from a tropical system. But that potential exists with Harvey.)

Consensus models now predict that peak rainfall totals will be around 35 inches in association with Harvey. This is due to the dual facts that Harvey is currently a very moisture-rich storm and that the storm is expected to stall for between 5 and 10 days following landfall. The storm is predicted to hover along the coastline, drawing in an unusually intense flow of moisture from a much warmer than normal Gulf, and to generate severe thunderstorms hour after hour, day after day. And this kind of rain event, if it emerges, could produce a disaster of historic proportions for Texas.

It’s worth noting that rainfall totals could also exceed the consensus forecast. Some models are now predicting upwards of 50 or 60 inches of rainfall by the time Harvey leaves the Texas area later next week (see top image above). The highest rainfall amounts ever produced by a tropical cyclone, in our records, for Texas is 48 inches. But there’s at least some possibility, with the perfect rainstorm that appears to be shaping up in Harvey, that these ultimate rainfall totals will be exceeded and a disaster of unprecedented proportions could emerge. But even if this worst-case doesn’t emerge, a 35 inch rainfall event would wreck untold destruction upon Texas’s southeastern cities.

Harvey strengthening as it moves toward shore

( Harvey rapidly strengthening to CAT 4 as it nears landfall. Image source: National Hurricane Center.)

Normally soft-spoken forecasters like Bob Henson and Eric Holthaus are not mincing words over the potential severity of the present situation. Last night, Bob Henson on twitter asked people: “Please don’t fixate on whether Harvey arrives as a Cat 2, 3, or 4. It’s the mammoth rainfall amounts (up to 35″) that will affect millions.” Meanwhile, Eric Holthaus warned: “This is scary. I have never seen a rainfall forecast like this in my entire career. Texas will be recovering from for years.”

Of course, we could dodge a bullet and rainfall totals could be lower for Harvey. It’s just that this event is currently trending toward a near worst case or worst case deluge-type storm that produces very heavy rains over the same region over nearly a week-long period.

Conditions in Context — This is Not Your Father’s Atmosphere

(The number of record rainfall events has increased dramatically during recent years. An observation attributed to human-forced climate change. Image source: Increased Record-Breaking Precipitation Events Under Global Warming.)

During recent years, a warmer than normal atmosphere has been producing more and more intense rain storms. The number of record daily rainfall instances around the world has been rising precipitously (see image above). This increasing severity is, in large part, due to the fact that human-forced warming amps up the hydrological cycle — producing more intense rain storms and more intense droughts. In other words, the climate dice are loaded for extreme rainfall and droughts in the present atmosphere. And it is in this atmosphere that Harvey has emerged. So we shouldn’t at all discount the fact that Harvey’s potential worst impacts from rainfall are now higher than they would have been even just a few decades ago. And this is one of the major reasons why we are seeing such a historic potential out of Harvey.

UPDATED (4)

UPDATE (5): As of 800 PM CDT the eye of Harvey crossed the coastline somewhere between Corpus Christi and Port O’Connor. Unfortunately, this storm is just getting started as a very severe one week long rain event is about to follow.

UPDATE (6): As of 1000 PM CDT and just following landfall, Harvey’s minimum central pressure had fallen to 938 mb. An indication that the storm was still strengthening as it began to cross the coastline. According to these reports (here and here), this is the 4th lowest barometric pressure recorded for a hurricane at landfall on the Texas coast since 1900. Maximum sustained winds remained at 130 mph with gusts to 160 mph.

Links:

National Hurricane Center

National Weather Service

Increased Record-Breaking Precipitation Events Under Global Warming

Greg Carbin

Eric Holthaus

Bob Henson

Hat tip to Greg

Hat tip to Titania

Hat tip to Wili

Hat tip to Andy in San Diego

Hat tip to Wharf Rat

Hurricane as Rain Bomb — Rapidly Intensifying Harvey Threatens to Dump 20-35+ Inches on Texas

A hurricane moving over the much warmer than normal waters of the Northern Gulf of Mexico is expected to rapidly strengthen to major status with 125 mph sustained winds over the next 12 hours before making landfall. Such rapid intensification brings with it the risk of severe storm surge flooding and damaging winds along the U.S. Gulf Coast. However, one of the most worrying features of this system is that it is incredibly moisture rich and new models now show a potential that the storm will dump as much as 20-35+ inches of rain across parts of Texas as the storm stalls over the region for 5-6 days.

(Present model guidance for Hurricane Harvey’s rainfall totals show a significant flooding potential for Texas. Note that maximum rainfall potential in this model is 40.6 inches.)

By late afternoon on Thursday, Harvey was a minor hurricane packing 85 mile per hour winds with a minimum central pressure of 976 mb and moving through the Central Gulf of Mexico on a path toward Texas. The storm was about 305 miles to the southeast of Corpus Christi, Texas and was moving toward the northwest at about 10 miles per hour. A curve toward the north is expected in the next 12-24 hours. Such a track would bring the storm adjacent to the Texas coast by some time late Friday or early Saturday.

As the storm moves north and west, it is expected to tap the warmer than normal waters of the Gulf of Mexico in the range of 87 to 88 degrees Fahrenheit and rapidly intensify into a major hurricane packing 125 mile per hour or higher winds.

(Rapidly intensifying Harvey approaches the Texas coast on Thursday. Image source: The National Hurricane Center.)

This is presently a very dangerous situation with the National Hurricane Center warning, as of the 4 PM CDT advisory that the storm is still expected to ‘rapidly intensify.’ And that peak intensity estimates could be conservative at this time. The storm will then bring 6-12 foot or higher surges to parts of the Texas Coast before moving slowly inland.

We should point out that some of the model guidance from earlier in the day predicted a very intense storm. This morning’s GFS run showed a 938 mb minimum central pressure just before the eye wall landfall late Friday. Such pressures are more consistent with a category four storm with maximum sustained winds in the range of 130 to 156 mph. This afternoon’s intensity guidance from GFS has backed off a little bit to 948 mb — which is more in the range of a strong Category 3 storm which jibes with the most recent NHS predicted intensity of 125 mph.

(Harvey may be stronger than even current NHC guidance indicates. GFS models from earlier this morning showed a 938 mb storm by late Friday. Intensity in the models has subsequently backed off to 948 mb — which is equivalent to the strong category 3 strong that the National Hurricane Center now predicts. Image source: Tropical Tidbits.)

As the eyewall reforms and the storm’s intensification rate varies, we’ll tend to end up with different peak intensity forecasts. In any case, we are looking at a major hurricane producing serious impacts for Texas and the U.S. Gulf Coast over multiple days.

Present model guidance further predicts that Harvey will slow down and then stall over southeastern Texas after making landfall — remaining basically stationary near the coast until Wednesday. As it hovers over this region, the storm will pull warm, moist air in over Eastern Texas while maintaining tropical storm intensity, generating a 5 to 6 day long severe flood event. In some scenarios, the storm may partially re-emerge over the Gulf and restrengthen. By Thursday, Harvey is expected to be picked up by a frontal system dipping in over the Central U.S. Exiting the state as it moves north and east.

(Harvey’s associated thunderstorms boil with hot intensity in this GOES satellite picture. Watch an animation of the massive storms swirling around Harvey here.)

Such a long-term stall is expected to bring significant torrential flooding rains over parts of Southeastern Texas. With averages of 17-32 inches over a wide swath and as much as 35+ inches in isolated locales. It’s worth noting that with Harvey’s top intensity continuing to trend toward major hurricane status, with a human-warmed atmosphere now capable of producing much more intense rainfall events, and with the storm expected to rain out over such a long period, some of the ultimate rainfall totals could be historic.

From the National Hurricane Center:

“The system is likely to slow down once it reaches the coast, increasing the threat of a prolonged period of heavy rain and flooding across portions of Texas, southwest Louisiana, and northeastern Mexico into early next week.”

(UPDATES TO FOLLOW)

Links:

The National Hurricane Center

Tropical Tidbits

Pivotal Weather

The Capital Weather Gang

Hat tip to Bostonblurp

China Builds 24 Billion Watts of Solar in Just Two Months as Trump Attacks Renewables and Defends Coal

Between the present U.S. Executive Branch and China, we can really tell which government is serious about being a moral leader on the critical issue of climate change and which government continues to wallow in the land of backwards thinking and heartless denial. For as the Trump Administration is doing everything it can to defend the coal-fired ‘Satanic mills’ that are so radically transforming the world for the worst while attacking renewable energy, China is continuing to build the solar farms that are capable of replacing them like gangbusters.

More than 10 Billion Watts Per Month

In June, China added a staggering 13.5 billion watts (gigawatts) of solar panels to its present large and growing solar fleet. In July, the country added another 10.5 gigawatts of solar. The two month total of 24 gigawatts is more than half the size of the total U.S. solar fleet of 44.4 gigawatts. In other words, China just added more solar capacity in two months than the U.S. added in all of the past two years.

(New solar market guidance for China shows an expected 180 to 230 GW of solar capacity by 2020. The present build rate indicates that even this range may be conservative. Image source: Renew Economy.)

As a result of this amazing build pace, China has already smashed through its 2020 solar goal of 105 gigawatts. The country now boasts a solar fleet of 112.3 billion watts. Long range forecasters now expect China to approach or exceed 200 gigawatts of solar by 2020 — or more than 20 percent the size of China’s present (and shrinking) coal fleet. And if China somehow maintained its amazing rate of solar installation during June and July, the country would exceed 200 gigawatts of national solar capacity by May of 2018.

No one presently expects that to happen. But China has surprised the world before. This is exactly the kind of surprise that a world wallowing in the ever-worsening impacts of climate change so desperately needs.  And the irony is that this new hope for rapid carbon emissions reductions is coming from China. Not the supposedly enlightened and progressive United States which is presently afflicted by the absolute worst form of backward-looking executive leadership imaginable.

Moral Leadership on Climate Change or Loss Thereof

I’m betting the people of the U.S. don’t want to be led down the path toward a new dark age of every worsening climate change and a fossil fuel resource curse write large by Trump. That we would much rather do our part to save the world from ramping climate destruction while taking leadership roles in the very new industries that U.S. innovation helped to create.

(Whether you’re optimistic or pessimistic about Earth’s climate sensitivity, the pathway toward worst case climate change [otherwise known as business as usual] lies in a world that continues to burn coal. So Trump’s defense of coal and attacks on renewables are, in essence, a defense of the worst case when it comes to climate change related disasters. Image source: The Brookings Institute.)

So what do we do?

We let the world know that Trump’s brand of leadership is not acceptable to Americans. That the true government leaders in the U.S. are those like California and Vermont and New York. That we support the future industries like those being pioneered by Musk and so many others. That we do not fear the future so much as recognize and embrace its mighty and admittedly difficult challenges. That we rise to the occasion by fighting for carbon emissions reductions and we do not falter.

Links:

China Added 10.5 Gigawatts of Solar in July

Trump’s Attack on Renewable Energy

Scott Pruitt’s Big Coal Lie

Renew Economy

The Brookings Institute

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