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Southeast Texas Hammered by 15+ Inches of Rain

It doesn’t take a hurricane or tropical storm to dump massive amounts of rain on southeast Texas these days. Just a wave of tropical moisture from an ocean warmed by human-caused climate change.

(Not a hurricane, but southeast Texas may see 20 inches or more of rain this week.)

Over the past few days, a massive surge of moisture has flowed off the warmer than normal waters of the Gulf of Mexico. This moisture has interacted with a trough dipping down over the Central U.S. to produce prodigious amounts of rainfall. And ever since late Sunday powerful thunderstorms have been firing across the Texas coast.

As of this morning, according to reports from The National Weather Service, between 5 and 15 inches of rainfall had inundated a vast swath stretching from the Texas-Mexico border northward to a Houston area still recovering from Hurricane Harvey’s historic floods. These heavy rains, producing amounts typically seen from a substantial tropical cyclone, have generated major flooding and flash flood warnings across the region. As the waters rise, residents have become justifiably concerned about personal safety and damage to property.

NOAA forecasts indicate that storms expected to continue firing through Thursday, with between 2 and 7 inches of additional rainfall possible. It is worth noting that atmospheric moisture levels over the region are very high. So predicted rainfall totals may be exceeded.

(As of 7 AM, more than 15 inches of rain had fallen over parts of southeast Texas in association with a persistent upper level low and related severe thunderstorms. Heavy rains have continued to fall throughout the day and aren’t expected to abate until at least Thursday. Image source: The National Weather Service.)

During recent years, increased global temperatures have generated more extreme rainfall events for places like southeastern Texas. Warmer ocean surfaces — like those in the heating Gulf of Mexico — evaporate more moisture into the atmosphere. And this moisture generates more fuel for storms — greatly increasing the peak rainfall potential of the most intense storms.

Last year, southeast Texas faced inundation from a number of severe events. A sequence that was capped off by the record-shattering Hurricane Harvey — which tied Katrina as the costliest U.S. storm on record and dumped more than 60 inches of rainfall over parts of the state. Though the present storm event is not likely to reach Harvey levels of extremity, it is a stark reminder that we have entered a new climate and extreme weather regime. One that will continue to worsen so long as we keep burning fossil fuels and forcing global temperatures to rise.

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Ellicott City Flood — 1,000 Year Event Looks a Lot Like One of the Rain Bombs of Climate Change

We live in a strange new world, one in which the familiar is all mixed up with the radically altered. Such was the case this weekend when a weather pattern that was pretty normal for summer spawned a single thunderstorm that produced a once-in-a-thousand-years flood event in Ellicott City.

Normal Weekend, Typical Weather Pattern, Abnormal Conditions

On Saturday, my wife and I readied to trek out to Shenandoah National Park for a happily-anticipated summer camping trip. As we headed out the door, the weather pattern looked mostly normal for summer, if a little stormy. A high-pressure system out over the ocean was pulling in moisture off its waters and drawing warm air up from the south. A low over western Pennsylvania and a warm frontal boundary over Maryland created instability in a big zone of convection from Northern Virginia on through to Connecticut. Overall, it was a pretty typical pattern that would probably have produced some moderate-to-strong late-afternoon thunderstorms back in the 20th century. Back then, it was far less likely that a similar pattern would have produced a 1,000 year flood event.

Extreme Ocean Heat 2

(Extremely warm sea surface temperatures on the weekend of July 30-31 helped to fuel the record rainfall event over Elicott City, Maryland. Sea surface temperature anomaly map provided by: Earth Nullschool.)

However, conditions were not normal, not the same as they were back during a time when human fossil-fuel emissions hadn’t forced the world to warm by 1.2 degrees Celsius above 1880s levels. In the new world in 2016, the ocean high-pressure system was circulating over record warm sea surfaces that were 3-5 C hotter than late 20th-century averages. And because of this, the ocean was bleeding off a whole hell of a lot more moisture than it typically would. Any storms that fired in that very wet air mass would, as a result, tend to pump out a lot more rain than is typical.

A Wet Atmosphere Crackling with Unusual Energy

As my wife and I made our way toward the Blue Ridge Mountains and down Interstate 66 and Route 211, large, energetic cumulus clouds sprouted all around us. Wafted in the hot, unstable air, many tops punched up through the troposphere, spreading out into the characteristic anvil shapes of thunderstorms.

Light streamed down between these big, wet beasts. For a while, as we made our way up to the campground, set up our gear, and took a hike along a local rock scramble, we were fortunate — able to enjoy our day despite the loud rumbles and roars of thunder echoing up from the valleys or off the nearby mountainsides in the steamy, moisture-choked air.

Available Rainfall Saturday

(A massive amount of atmospheric moisture fueled powerful thunderstorms on Saturday, July 30 from the Appalachians of northwestern Virginia to the Baltimore City region. One of these storms dumped more than 4.5 inches of rain on Ellicott City, Maryland Saturday in just one hour. Image source: Terp Weather.)

At about 3,000 feet in elevation, these conditions were a bit odd for Shenandoah National Park which typically experiences milder weather. Temperatures were around 80 degrees Fahrenheit (about 5-6 F hotter than average), and the level of atmospheric moisture was amazing. Great, steamy clouds kept rolling up the mountainsides. They made the air heavy and full of shapes dancing with light and shadow, seeming to give it the character of some alive thing sprouting a thousand wet heads and arms.

The big thermals and thunderstorms were supported by hotter temperatures into the 90s (F) down in the valleys. And the storms were taller, bearing more moisture, engorged by a hot atmosphere whose temperatures and water vapor levels are now probably unlike anything seen in at least the past 115,000 years — conditions that would have devastating effect just a couple of hours later and about 100 miles to the east in Ellicott City.

Returning to camp, as we prepared for a hearty dinner of tempeh and veggie pasta, thunder from the southwest grew ever closer and a rolling wave of cloud seemed to spill in through the trees, spreading mist and heavy rain over everything nearby. In just a few minutes, we were scrambling into our vehicle and watching as torrents of rain streamed down, transforming the mountaintop campground into a world of rushing water.

Thunderstorm Dumps More Rain on Ellicott City than Any of the Past Deluges or Hurricanes in its History

At about the same time that my wife and I were scrambling for cover, another massive thunderstorm was bearing down on Ellicott City, Maryland. The storm hit one of the densest pockets of atmospheric moisture in that big bleed off the record-hot Atlantic Ocean and just exploded. Packed with all that unusual and heat-fueled moisture, the storm then began to dump its amazing and unprecedented torrents on this historic town of 65,000 just 20 miles to the west of Baltimore. In only 60 minutes this massive thunderstorm managed to unload 4.5 inches of rainfall. Two-hour rainfall totals approached six inches.

(Restaurant-goers in Ellicott City watch in shock as the street below floods and sends vehicles hurtling past. Video source: Ellicott City Flash Flood.)

Streets were rapidly flooded as the Patapsco River rose to a record 14 feet and leaped over its banks. The main road running through the center of town became a four-to-six-foot-deep torrent that hurtled vehicles along its path or into buildings. First responders scrambled to rescue more than a hundred motorists who were suddenly stranded in the flash flood. Tragically, two people lost their lives.

The force of the flood was so energetic that not only were many of the historic buildings in town damaged, but some had their very foundations torqued off-center, twisted by the great energy of the sudden flood waters churning through town. The Maryland government has declared a state of emergency, but it is uncertain how long it will take to make repairs or how much that is irreplaceable has been lost in the flood.

Two 100+ Year Flood Events For Ellicott City in the Past Five Years

The Washington Post’s Capital Weather Gang appropriately notes that Ellicott City is a pretty vulnerable place for floods:

It’s a highly vulnerable spot, an urbanized strip along the bottom of a deep valley through which the Patapsco River flows. This place, historic Ellicott City, Md., has seen plenty of serious floods: 1868, 1923, 1952. More recently, the remnants of Hurricane Agnes (1972) left an extreme high-water mark, measured in many feet. The Great Mid-Atlantic Flood of June 2006, once again drowned parts of the town.

And another big flood back in 2011 pushed the Patapsco River to 11 feet, prompting a local art gallery to build a 20-inch-high flood barrier. But the unforeseen flood that roared into Ellicott this past Saturday was the worst among all of these. As a result, most protections and flood barriers previously erected were quickly overwhelmed.

Phoenix Macroburst 2

(Dramatic microburst over Phoenix, Arizona on July 21, 2016. Each degree Celsius of warming increases the atmosphere’s water vapor content by about seven percent. This increase, along with other factors such as intensified convection and rising cloud tops, escalates the frequency of extreme rainfall events like the July 30, 2016 Ellicott City flood. Image source: GGferg.)

Two-inch-per-hour rainfall amounts are usually enough to completely overwhelm most drainage infrastructure, overtop banks, and turn streets into rivers. Ellicott City saw nearly six inches of rainfall in two hours and 4.56 inches of rainfall in just one. Such events are typically seen as quite rare (100-year events or more) and building codes do not often account for them. Managing so much water is a major engineering challenge and requires a great deal of investment. Spending so much money on flood defense systems for a storm that might happen in 100 years or 1,000 years can sometimes seem like a waste at the time.

However, in a world warmed by climate change, such floods are happening with greater frequency. A 100 to 1,000 year flood may happen every five years or so in some locations (as has been the case with Ellicott for 2011 and 2016). The atmosphere is loaded more and more with both heat and moisture. The troposphere is taller due to the heat. The oceans are warmer and bleed more moisture. All these factors combine to make even pop-up storms more intense and to generate the 100 and 1,000 year events with a higher frequency in the present day. And as the world continues to warm, such severe storms will become ever more common.

Links:

Ellicott City Gets Rainfall Expected Only Once in a Millenium

Two Dead, 100 Rescued as Ellicott City Flood Causes Tremendous Devastation

Ellicott City Flash Flood

Earth Nullschool

How an Off-the-Charts Flood Ravaged Ellicott City

NASA GISS

Terp Weather

Hat tip to Colorado Bob

Hat tip to DT Lange

Hat tip to Greg

Hat tip to Griffin

The Merciless Rains of Climate Change Hammer Houston, Southeast Texas — 12-18 Inches Accumulation, More Than 1,200 Water Rescues Reported

“I can hear your whisper and distant mutter. I can smell your damp on the breeze and in the sky I see the halo of your violence. Storm I know you are coming.”

*****

The atmospheric ingredients right now are ripe for some serious trouble. Globally, the world is just starting to back away from the hottest temperatures ever recorded. This never-before-seen heat plume, driven on by a fossil-fuel abetted warming not seen in at least 115,000 years and an extreme El Nino combined, has loaded an unprecedented amount of moisture into the Earth’s atmosphere. As El Nino shifts toward La Nina and the Earth marginally cools, a portion of this massive excess of water vapor is bound to fall out as rain — manifesting as terrible extreme precipitation episodes that can result in serious trouble. A seemingly endless procession of freak events that challenge the record books time and time again.

Across the world, we’re starting to see such episodes now. Over the past week, Iran, Yemen, Qatar Saudi Arabia and Afghanistan have experienced flash floods resulting in loss of life. Severe floods spurred a major emergency response effort in Central and Northern Russia this weekend. And in Santiago Chile, streets turned into rivers as a sudden and extraordinary deluge both polluted the water supplies of 1 million people and transformed the world’s largest copper mine into a lake.

(Severe flooding around the world this week includes the Houston area — sections of which have essentially been crippled by 12-18 inches of rainfall over the past 24 hours. In total, more than 1,200 water rescues have been reported throughout the region. Many residents, like the gentleman above, appear to have been shocked and surprised by the flooding’s severity. Video source: Houston ABC News.)

Sudden, Extreme Flooding in Houston Area

In the US, the City of Houston and the region of southeastern Texas experienced its own extreme deluge. There, a stubborn and unyielding high pressure system over the US East Coast, an omega block in the Jet Stream, a cut off upper level low, and a nearly unprecedented amount of moisture streaming in from the Gulf of Mexico and regions to the Equatorial South all conspired to aim a train of powerful storms in the form of an eye-popping mesoscale convective system (MCS) at the Houston region. Since early this morning, between 12-18 inches of rainfall fell over the city’s western suburbs with 6-8 inches inundating the city center. In some places, rates of rainfall accumulation hit a crippling rate of nearly 4 inches per hour.

According to Bob Henson at Weather Underground:

… the Houston area was socked on Monday morning by a huge mesoscale convective system (MCS) that drifted southeast across the area, dumping eye-popping amounts of rain: 6” – 8” over central Houston, with 12” – 18” common over the far western suburbs… While individual thunderstorms often weaken after dark, the large mass of thunderstorms that makes up an MCS will often persist overnight and into the next morning, as the MCS cloud tops radiate heat to space and instability is enhanced.

The record single day rainfall total for Houston before today was 11.25 inches. It appears likely that 11.75 inches recorded at Houston International Airport today will mark a new daily high mark for a city that grew up out of fossil fuel burning but now appears to be drowning in the heat-intensified effluent. More to the point, most of Houston’s western suburbs experienced what amounts to an entire typical season’s worth of rainfall in just one 24 hour period.

Drainage systems, not designed to handle anywhere near so much water over so short a period, were rapidly overwhelmed. By midday, more than 70 subdivisions in the Houston region were reported flooded, more than 1,200 vehicle water rescue operations had been conducted along the inundated region’s streets and highways, and more than 1,000 homes were inundated. Seven hospitals were shut down, airport operations were crippled, and more than 100,000 people were reported to be without power. The Weather Channel’s Jim Cantore, not known for understatement, may have hit a bit below the mark when he noted that “this is a mind boggling situation” earlier this afternoon. CNN, in its summation report of this, most recent, disaster declared that the entire city had been basically shut down.

Extreme Storms Houston Texas

(River of moisture flows up from the Equator and Gulf of Mexico and into the Houston region on Monday — spurring extreme rains that cripple the city. A pair of doggedly persistent weather systems — a blocking high to the east and an upper level low to the north contributed to the extreme weather over Houston. Climate change related features like record atmospheric moisture loading, and persistent ridge and trough generation due to Jet Stream changes likely linked to record low Arctic sea ice levels also likely influenced today’s severe storms. Image source: LANCE MODIS.)

As of early this evening, a series of somewhat less intense storms still trailed through the Houston region as heavier rains marched off toward the east over Louisiana and Arkansas. A strong moisture flow is expected to persist over Eastern Texas and the southern Mississippi River Valley region through to at least Thursday as both the upper level low and blocking high complicit in Monday’s extreme flooding in Houston appear reluctant to budge from their current positions. As a result, NOAA is predicting another 4-5 inches of rainfall for areas near and just to the North and East of Houston over the next seven days. To this point, it’s worth noting that NOAA’s precipitation models had ‘only’ predicted about 4 inches of rainfall for the past 24 hour period in the near Houston area — a period that produced about five times that total for some locations. So it appears that weather models may be having a little bit of trouble managing the new and extremely dynamic atmospheric conditions now coming into play.

But One Extreme Event of Many in the Past Five Months

Houston’s likely record rainfall for this time of year comes on the back of hailstorms generating up to a billion dollars worth of damage over Northeastern Texas last week and follows a record March inundation of the Mississippi River region just to the North and East. An event that also followed a freak December flooding of Missouri and Illinois which likewise re-organized the record books. Overall, this represents an extreme spate of severe weather for one localized region.

Consistent trough generation in the Jet Stream over the area (likely influenced by record low Arctic sea ice coverage), consistent above average sea surface temperatures in the Gulf of Mexico, a strong moisture flow from a record El Nino, and record global temperatures contributing to high atmospheric moisture loadings all influenced severe storm formation over this area during recent months. Sadly, it’s a spate of severe weather that is likely to continue at least until the end of Spring.

Links:

Widespread Flooding, More than 1,000 Water Rescues in Houston Area

Houston Largely Shut Down Amidst Severe Rainfall, Flooding

Massive Flood in Houston

Houston Texas Average Rainfall

Flash Floods Claim 18 Lives Across Saudia Arabia

Deadly Rains Pound the Middle East

Flash Floods in North Afghanistan Claim 38 Lives Overnight

World’s Largest Copper Mine Shut Down in Santiago Flood

As A Titanic El Nino Begins to Fade, What Fresh Trouble Will Record Warm World Bring?

NOAA Quantitative Predictive Forecasts

Punishing Four Season Storm Grips US

Mangled Jet Stream, River of Moisture Set to Deliver Severe Flooding to Mississippi River Valley

Houston ABC News

Hat Tip to Colorado Bob

Hat Tip to Greg

Hat Tip to DT Lange

Hat Tip to Daniel Hatem

Monster El Nino Hurls 43+ Foot Waves at US West Coast

For NOAA, it looks like we’re well on the way toward seeing one of the most powerful El Ninos ever recorded. And already, there’s some brutal Fall and Winter weather events starting to emerge as a result. One event, in particular, is today roaring into the US West Coast like a Godzilla-hurled freight train.

It’s just one upshot of a Monster El Nino in a record warm world. A weather and climate event — one likely pumped up by an overall atmospheric warming of 1 C above 1880s levels — that will likely continue to have severe and worsening global impacts over the coming months.

image

(Ocean waves hit insane heights of 43 feet [13.2 meters] today as another powerful storm roars into the US West Coast. Image source: Earth Nullschool.)

One of the 3 Strongest El Ninos On Record

NOAA’s September, October, November ONI Index, the key zone for measuring El Nino strength, hit a +2.0 degree Celsius positive anomaly this week. That’s just 0.3 C shy of the most powerful El Nino ever recorded — 1997-1998 which peaked out at +2.3 C in the same monitor. With October, November and December likely to show even hotter overall readings for the Central Equatorial Pacific, it appears that the 2015-2016 El Nino will strike very close to this ONI high mark. Peak weekly sea surface temperature values already exceeded top 1997-1998 temperature levels for NOAA (+2.8 C for 1997-1998 vs + 3.1 C for 2015-2016). So we wait on the ONI three month measure for October, November and December to give broader confirmation.

The other major El Nino monitor — the Bureau of Meteorology (BOM) in Australia — has weekly sea surface temperatures peaking at +2.5 C in the same zone. This is 0.2 C short of peak 1997-1998 values. BOM notes that the current El Nino is near peak and that, according to its own measures, is unlikely to exceed 1997-1998 but will likely hit within the top 3 strongest events. According to BOM:

The 2015–16 El Niño is strong, and likely to rank in the top three events of the past 50 years. Presently, several key indicators fall short of their 1997–98 and 1982–83 values, both in the ocean (e.g. sub-surface temperatures, which have peaked around +8 °C this year, compared to +12 °C in 1997–98), and atmosphere (e.g. SOI, for which monthly values peaked around −20, while 1982–83 had several months at −30).

NOAA sea surface temperature anomalies

(NOAA Equatorial Pacific sea surface temperature [SST] anomaly tracking appears to indicate that the 2015-2016 El Nino may have hit peak during mid November. Though a second peak is possible in December, atmospheric and ocean trends will tend to push for gradual SST cooling over the coming months. Overall, the 2015 to 2016 El Nino is likely to be among the top 3 strongest on record. A climate event that in a world warmed by 1 C above 1880s values has the potential to set off some very extreme weather over the coming months. Image source: NOAA SST Anoms 5N to 5S.)

Based on a reading of these two analysis by expert agencies, we revise our previous statements to come into line with NOAA and BOM forecasting. Though it’s still possible that 2015-2016 may exceed peak 1997-1998 intensity, it is more likely that the current El Nino will fall into the range of the top three most intense such events. This is likely due to the fact that El Nino has probably already peaked and that though some indicators show 2015 as exceeding 1997-1998 in intensity (NOAA weekly SST values), the broader, long-term indicators still rank 1997-1998 as the most intense in the modern record.

Potentially Very Severe Weather on The Way

That’s not to say that related weather events won’t be quite extreme. In some respects, hottest ever atmospheric and ocean temperatures on a global basis provide even more available energy for storms, heavy rainfall, droughts, and wildfires. Globally, the Earth has warmed by between 0.2 and 0.3 C from peak 1997-1998 atmospheric temperature values to those we are likely to experience during 2015 and 2016. That means rates of evaporation and precipitation have increased by about 2 percent overall. In addition, new climate instabilities have tended to arise due to increased rates of glacial melt, polar amplification (especially in the Northern Hemisphere), and related ocean surface warming along with the weakening of some of the major oceanic heat conveying currents.

A top 3 strongest El Nino firing off in this global climate environment is, therefore, not entirely the same creature as a Monster El Nino firing off during the 1980s or even the 1997-1998 El Nino. In particular, the added atmospheric moisture loading, the slowing down of the Gulf Stream off the US East Coast and related back-up of warm water in that region, and the added rates of evaporation due to overall warming of the Earth-Ocean system present potentially more severe drought hazards for regions like Brazil and Australia, potentially more severe extreme storm hazards for the US West Coast as the storm track ramps up, and potentially more severe Winter oceanic and coastal storm hazards for the US East Coast, the North Atlantic and the United Kingdom.

Disaster Officials Worry, Make Calls For Readiness

Federal disaster officials are keenly aware of these risks and have been issuing warnings for regions of the US West Coast since October. NOAA and FEMA bulletins have urged people to keep extra food and water on hand and to prepare for extended periods of sheltering in place during heavy rainfall, landslide, snowfall or coastal flooding events. Statements today continue to urge preparedness for what is likely to be a very extreme Winter weather season. In San Jose Mercury News, FEMA emergency manager Bob Fenton expressed his extreme concern today after a disaster preparedness drill in Sacramento:

“It is critical that citizens take the risk seriously. If you hear a warning to evacuate, act accordingly. People often want to ‘wait and see’ — but, please, don’t wait. Everything can be replaced, but your life can’t.”

The US Southwest and South-Central California are especially vulnerable to severe flooding events during strong El Ninos in the December, January, February timeframe. Such events can deliver powerful rivers of tropical moisture to this region. Called Pineapple Express, these atmospheric rivers can develop along an arc running from the Equator, through Hawaii and then terminating over the US Southwest. The most extreme of these events have the potential to deliver 200, 500, or 1000 year deluges resulting in many feet of rainfall for the Central Valley region. A situation that some researchers have called an Ark-Storm and have linked to the (likely El Nino-related) Great Flood of 1862.

In today’s context, we have one of the top 3 strongest El Ninos firing off in an atmosphere that, due to human forced warming in the range of 1 C, sees an overall 7-8 percent increase in the rate of evaporation (vs 1880s contexts) and precipitation. So any river of moisture that does develop may likewise become further engorged than was previously typical, thus resulting in more severe rain storms and a related heightened flood risk. It’s a risk, that in any case, FEMA disaster managers are taking very seriously.

43 Foot Waves off US West Coast

As officials issued warnings and FEMA managers drilled in Southern California, another powerful storm packing 60-80 mile per hour winds, heavy rains, and 43+ foot waves roared into the US West Coast this week. The 960 mb storm kicked off coastal flood, gale and storm warnings from Northern California through Washington State.

West Coast Storm

(Another powerful storm roars into the US West Coast bringing with it flooding rains, heavy surf, coastal storm surges, and mountain snows. The currently very strong El Nino is likely deliver more severe storms of this kind over the coming months. Image source: NOAA GOES.)

Interior flood warnings were also issued as between 4 and 18 inches of rain fell over the past 3 days with 2-4 inches more expected today. The event had already spurred over 9 landslides even as, according to the Weather Channel, more than two dozen river gauges had topped flood stage across Washington and Oregon. It’s a heavy soaking that began in November and just keeps getting worse with each new storm.

These storms are fueled by a powerful flood of heat and moisture boiling off the Godzilla El Nino in the Pacific. A dynamic that’s generating an extraordinarily powerful Pacific storm tack. This week, models predict another extreme storm — one that is expected to bomb out as a 930 mb monster packing 75 kt winds and 52+ foot waves in the Bering Sea between Russia and Alaska. And given the way El Nino is charging up the atmosphere, these Pacific beasts are bound to keep roaring on in.

 

Links:

Climate Prediction Center — Cold and Warm Episodes by Season

Monster 2015 El Nino May Be Most Intense Ever Seen

Earth Nullschool

Pacific Northwest Storm Parade to Bring Rain, Wind and Snow

NOAA SST Anoms 5N to 5S

Federal Officials Warn Californians to Prepare for Onslaught

NOAA GOES

NOAA Ocean Prediction Center — Pacific

Hat tip to DT Lange

 

 

North Atlantic Ramping up to ‘Storms of My Grandchildren’ to set off Major Flood Event for Tempest-Tossed England?

Storms Reshape England's Coastline

(Storms Reshape England’s Coastline during Winter of 2013-2014. Image source: AGU)

Under the ongoing insults of human-caused climate change, the North Atlantic is ground zero for the potential development of the worst storms humankind has ever experienced. And indications are that the ramping up to this dangerous time may well be starting now.

The temperature related weather instabilities between the warming North Atlantic, the melting but still frigid ice packs of Greenland, the retreating polar sea ice, a continental North America enduring a series of polar vortex collapse events flushing cold air south as the Arctic experiences its warmest readings in an age, and an interior Europe and Asia that are also experiencing mass migrations of cold air fleeing the ever-warmer Arctic are just screaming.

A bite of warm air and related warm ocean water has flooded a large region between Scandinavia, Svalbard and Novaya Zemlya, making its home where winter sea ice once resided. The waters near Greenland are now melt-cooled by the 500 gigatons of average annual glacial outflow occurring there. And the never-ending influx and concentration of heat in the Arctic has set the Jet Stream into a fit of wild loops and whirls.

All these changes result in a high degree of weather instability, in a setting off of extreme weather events, of great switches from cool, to extreme hot, from record drought to record deluge. In the past few years we’ve seen these kinds of extreme weather events occur with increasing frequency. But now, a new kind of extreme event is beginning to emerge, a kind of event that may well be prelude to ‘The Storms of My Grandchildren’ Dr James Hansen alluded to in his prescient book examining the ultimate consequences of an ongoing and devastating human greenhouse gas emission.

The Breeder of Storms: Our Warming-Ravaged North Atlantic

Ever since winter began to settle in, and the extreme effects of Northern Hemisphere temperature imbalance and Jet Stream changes began to take hold, the North Atlantic has become a breeder of extraordinarily powerful storms. According to reports from NOAA’s Ocean Prediction Center, the month of December alone featured 14 instances of hurricane wind events, 10 storms that experienced rapid intensification, and 5 storms that featured pressures of 950 mb or lower.

For comparison, a tropical storm that hits 950 mb is usually a category 5 hurricane. And for any ocean basin to show 14 instances of hurricane force winds let alone 5 950 mb and below storms over a one month period is extraordinary indeed. Imagine if the south Atlantic generated 10 hurricanes 5 of which were cat 5 in just one month and then you get a general comparison.

Two of these storms were particularly intense with one reaching 940 mb and another deepening to an exceptionally low 929 mb (the lowest reading ever recorded for the North Atlantic was 916 mb). By comparison, the freakish monster that was Hurricane Sandy bottomed out at 940 mb.

It is worth noting that the storms of the North Atlantic typically spread their energy out over larger areas than a tropical system. So though pressures are low enough to be comparible with the most intense tropical storms, the winds generated typically ranged from 75 to 100 mph while extending outward over hundreds of miles. By comparison, a typical tropical cyclone would have a very intense wind field within 20 to 100 miles of its center with intensity rapidly falling off beyond this zone.

Overall, the North Atlantic sees very few storms of 940 mb or lower, usually at the average rate of less than one every year. So for two to occur in the same month is exceptional indeed.

929 mb low raking the coast of England on Christmas Eve

(929 mb low rakes England with hurricane force winds on Christmas Eve, 2013. Image source: Lance-Modis.)

January also featured an almost endless cavalcade of intense storms rushing across the North Atlantic with numerous lows bottoming out below 950 mb (NOAA will issue a final tally sometime in February). Meanwhile, powerful storms developing in the North Atlantic continually pummeled Europe throughout most of the winter of 2012-2013 resulting in some of the worst rain and snowfall events ever recorded.

This recent climate-change driven shift of the North Atlantic into an increasingly stormy weather pattern may well be a prelude to even more extreme changes to come. Weather models produced by GISS and examined by premier climate scientist James Hansen indicate that very powerful storms arise in conjunction with increasing Greenland melt. Large pulses of fresh, cold water entering the North Atlantic were observed to create climate instabilities that resulted in very powerful storms with frontal systems the size of continents that packed the punch of hurricanes in the physical model runs. It was the likelihood that such storms could emerge by or before mid-century that, in part, spurred Dr. Hansen to write his prescient book — The Storms of My Grandchildren.

As noted above, the current Greenland melt outflow averages about 500 gigatons each year. This outflow is already large enough to weaken the Gulf Stream and set off severe weather instabilities. But with Arctic warming continuing to amplify and Jet Stream patterns bringing more and more warm air over Greenland, melt rates may triple or more over the coming decades, resulting in even more severe weather consequences. So the extreme storm patterns we see emerging in the North Atlantic now are likely just a minor prelude when compared to what we will witness as the years and decades progress.

England in the Firing Line: Windiest December Precedes Wettest January

Currently in the direct firing line of these powerful storms are the main islands of the United Kingdom. Throughout December, England suffered an almost constant assault of storms. In total, five storms, or more than one storm per week brought excessive rains and wind gusts in excess of hurricane force to the British Isles. The results were tens of thousands of power outages, major waves and storm surge events along the coastline resulting in damage to coastal structures and persons being swept out to sea, and increasing instances of flooding over saturated ground.

On record, December 2014 was one of the stormiest ever seen for the British Isles. According to weather data, the month was the windiest since record keeping began in 1969:

Wind Gust Measure Met

(Image source: UK Met Office)

In addition, December also ranked one of the rainiest with many locations seeing 3 times the normal level of rainfall for the month.

As the new year began, the series of severe storms impacting the UK continued unabated through late January. And as of the 28th, South England had experienced its wettest month since record keeping began in 1910. With a month and a half still remaining Southeast England had already experienced its 6th wettest winter season on record.

UK Rainfall

(Southeast UK Rainfall from 1910 to present with 2010 easily setting a new record. Image source: Met Office)

Dr Richard Dixon, director of FES Scotland when commenting in a Guardian interview about the most recent spate of anomalous UK weather noted:

“November and December were record breakers in Scotland, with storm after storm hitting around Christmas. Climate change is bringing chaos to our weather, not just increasing global temperatures but affecting ocean currents and global air currents. Scotland is caught between the changing influences of disappearing Arctic ice, the shifting jet stream and a weakening Gulf Stream. It is no wonder our weather is becoming less and less predictable. The consequences for us are more extreme weather, including more flooding.”

Very Dangerous Flood Situation for Southwesr England: Powerful Storm on the Way

The extreme rainfall, as of today, had resulted in a major flood event for Southeast England focusing on the Midlands and Somerset. The event inundated croplands, homes and farms throughout the rural region and spurred England to put its military on standby as forecasts show more rain and high winds are on the way. The anomalous event also spurred the 15th meeting of COBRA, the UK’s emergency response committee which has, increasingly, been called due to a continuous barrage of weather emergencies.

Somerset Floods

(Aerial photo showing homes, businesses and a vast area of land flooded in Somerset, England. Image Source: David Hedges)

In addition to the clearly visible inundation, numerous villages in the region have been cut off due to flooded roads for more than a week (with some areas being cut off for a month). The constant barrage of storms has resulted in both persistently high tides and almost continuous rainfall. The rainfall, trapped by high sea water, has nowhere to escape and simply pools, continuing to build up in the low-lying lands.

The UK’s conservative government’s response to the situation, thus far, has been anemic, waiting until today to declare the region a disaster area.

Unfortunately, another powerful storm is predicted to arrive by Saturday bringing with it yet one more spate of strong winds, heavy surf and driving rainfall to the already soaked region.

Saturday Forecast Map NOAA

(NOAA forecast map for Saturday. Note a powerful 953 mb storm forecast to impact the UK with 70+ mph winds and heavy rainfall. Image source: NOAA’s Ocean Prediction Center)

So if you’re living in Southeast England please do your best to remain safe, to heed government warnings, and to urge your government officials to provide you with the level of response you deserve during this dangerous time (including policy changes to reduce the rapidly increasing degree of harm coming from human caused climate change).

Early Storms Minor by Comparison

It is worth noting that, though more intense than we’re used to, these storms are the early, weaker outliers of a very dangerous period that is to follow. Our best models and our best climate scientists report the likelihood of far more dangerous storms emerging from this region and from the set of conditions that includes a weakening Gulf Stream, a melting Greenland, an amped up hydrological cycle and rapidly warming zones first at the northern polar region and then in the tropics. The eventual size of these storms could expand to cover continents and involve multiple linked and powerful storm centers. As noted above, Hansen warned of frontal storms large enough to blanket continents and with areas of hurricane strength winds stretching thousands of miles. We haven’t seen anything like that yet. And so the freakish and extraordinary weather we’ve witnessed this winter, and in recent years, is merely prologue for worse events to follow.

Links:

AGU

NASA: Lance-Modis

NOAA’s Ocean Prediction Center

UK Met Office: Winter Storms December 2013 to January 2014

Parts of England See Wettest January Since Records Began

UK Floods: January Rain Breaks Records in Parts of England

Colorado Bob’s Climate Feed

The Storms of My Grandchildren

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