Under the Arctic Dome — Brutish High Pressure System is Wrecking the Already Thinned Sea Ice

There’s a real atmospheric brute towering over the Arctic’s Beaufort Sea at this time. A high pressure system that would put shame to most other anti-cyclonic phenomena that bear the name. It is sending out a broad, clockwise pattern of winds. It is pulling up warm air from the Pacific to invade the Bering, Chukchi, East Siberian and Laptev Seas. And its torquing motion is shattering the already considerably thinned ice beneath it.

(A powerful high pressure system over the Beaufort Sea is predicted to further strengthen by late April 15. Image source: Earth Nullschool.)

Clocking in at 1046 mb of pressure, it makes typically strong 1030 mb high pressure systems seem weak by comparison. Over the next day it is expected to strengthen still — hitting 1048 mb by late April 15th (coming very close to an extraordinary 1050 mb system).

Shattered Sea Ice

This powerful and strengthening system has already been in place for about two weeks — slowly gaining momentum as its circulation has moved in mirror to the waters of the Beaufort Gyre that swirl beneath it. Masked only by a veil of sea ice considerably thinned by human-forced climate change, the waters of the Beaufort are now breaking through. Streaks of dark blue on white in an early break-up enabled both by a terrible Arctic warming and by this powerful spring weather system.

(Side-by-side images of Beaufort sea ice from April 4 [left frame] to April 13 [right frame]. Note the considerable and rapid advance of fracturing in a relatively short period. For reference, bottom edge of frame in both images is 500 miles. Image source: LANCE MODIS.)

Warm Storms

On the Siberian side of the Arctic, this massive high pressure dome is drawing in warm winds from the Pacific Ocean. Gust by gust and front by front, they come in the form of squalls that deliver above freezing temperatures and rains that blanket this thawing section of the Arctic. On Thursday, April 13, these warm winds had driven northward over 2,500 miles of Pacific waters to be drawn into storms that unleashed their fury — driving rains and gales through the already dispersed ice in the Bering Sea and shattering ice floes through the Chukchi. Today, April 14, these winds and rains drove northward to assault the ice of the East Siberian and Laptev seas.

(On April 13, above freezing temperatures, rains, and gale force winds ripped through the sea ice near Wrangle Island in the Chukchi Sea. Image source: Earth Nullschool.)

A Great Atmospheric Stack Drawing Heat into the Arctic

In the past, meteorologists like Stu Ostro envisioned that climate change would tend to produce towering high pressure systems — featuring increasingly strong storms roaring about their fierce outer boundaries. And the massive high lurking over the Arctic at this time is a good example of Ostro’s predictions coming to light in a region that is very sensitive to human-forced warming.

This great atmospheric stack appears to have had a considerable impact on the ice already — helping to push extent measures back into record low ranges by accelerating the melt trend. But these impacts are likely to spike over the coming week as this powerful high expected to remain in place through the next five days — continuing to draw warm air into the region.

(Global Forecast System models predict extreme warming over the Arctic Ocean throughout the next week resulting from the influence of a powerful high pressure system and very strong associated ridge in the Jet Stream. Image source: NCEP Global Forecast System Reanalysis.)

GFS model runs indicate that average temperatures over the Arctic Ocean region will hit a peak as high as 4 degrees Celsius above average by late next week. Meanwhile, the warmest zones are expected to be as much as 18-20 degrees Celsius above average. Such abnormal warmth at this time of year, if it emerges, will put a considerable damper on a freeze that should now be continuing in the High Arctic even as edge melt ramps up with the progression of spring.

This is particularly concerning due to the fact that temperature anomalies in the Arctic tend to fall off during spring and summer. In other words, such a powerful warming trend for the Arctic Ocean would be bad enough during winter — but it is an even more unusual event for spring. An ominous start to a melt season that could produce far-reaching regional and global consequences.

Links:

Earth Nullschool

LANCE MODIS

NCEP Global Forecast System Reanalysis

Stu Ostro

Climate Reanalyzer

Hat tip to Colorado Bob

Hat tip to Andy in San Diego

“Surreal” U.S. Wildfires Should Not be Burning in Mid-November

The smoke here in Atlanta has been surreal — Meteorologist Stu Ostro

*****

It’s a script that reads like something from the pages of a dystopian sci-fi novel:

In Dallas, on November 16, the thermometer hit 88 degrees Fahrenheit, breaking a 95 year old record. In Ada, Oklahoma the mercury struck 85 degrees F. Further north in high-elevation Denver, temperatures soared to 78 F — punching through a 75 year old record.

Meanwhile, strange, out-of-season wildfires continued to burn from the U.S. South to North Dakota and New England. In Atlanta, smoke streaming out of nearby wildfires blanketed the city. Red-eyed residents were increasingly forced to don protective masks beneath the choking late-fall pallor. In Chattanooga, over 200 residents were hospitalized from smoke inhalation and shortness of breath.

appalachian-wildfires

(NASA satellite image of smoke streaming out from Appalachian wildfires on November 16, 2016. Note that smoke plume stretches over large sections of North Carolina, Kentucky, Tennessee, South Carolina and Georgia — stretching all the way to coast and spilling out over the Atlantic. Image source: LANCE MODIS.)

Today, winds blowing out of the northwest pushed smoke over large sections of North Carolina, South Carolina and Georgia. And numerous additional locations issued air quality alerts.

Mass Mobilization to Fight Surreal Fall Wildfires

In the neighboring Appalachian region alone, more than 5,000 firefighters employing 24 helicopters and other pieces of heavy equipment have been battling blazes throughout forested lands for almost a week. A single fire in the North Georgia Mountains is larger in size than Manhattan. And with numerous large blazes raging throughout the region, about 130,000 acres has burned so far in an area that rarely sees large fires during summer — much less in the middle of November.

Asked about the situation, Weather Channel meteorologist Stu Ostro said — “The smoke here in Atlanta has been surreal, and [occurs] in the context of the persistent lack of precip and above average temperatures.”

Further north, wildfires have also sparked in New Hampshire, New York and North Dakota.

Conditions in the Context of Climate Change

In a number of cases, it appears that arsonists have ignited some of these fires. But warm conditions more similar to summer than fall have combined with an extreme drought spreading through the affected regions to push fire danger through the roof. So the impact of any ignition source is dramatically compounded by the heat and dryness. And the most intense fires are now burning in a region of extreme to exceptional drought centered on the mountains of North Georgia.

unseasonable-warmth-blankets-north-america

(Odd, unseasonable warmth blankets much of the U.S. and Canada in this surface air temperature anomaly map as wildfires rage in the southeast on November 16. Image source: Climate Reanalyzer.)

Such extreme drought and related intense warmth is not a normal climate feature for the southeast during November. Cool weather often dominates the North Georgia region at this time of year. But 2016, a year when global temperatures are now likely to hit 1.2 C above 1880s averages, brings with it an increasing likelihood of unseasonable heat and related rapidly developing drought in the affected areas. These fires, thus, occur under weather conditions that are consistent with what we would expect from human-caused climate change.

Links/Notes:

Stu Ostro

LANCE MODIS

Climate Reanalyzer

United States Drought Monitor

The National Inter-agency Fire Center

Note: Renowned and respected meteorologist Stu Ostro was generous enough to provide commentary on the smoke/fire situation in Atlanta — which includes a note on how odd he thinks the current situation is. That said, the analysis and assertion that the current situation is not normal and is related to climate change is my own initial observation. Stu’s inclusion in this analysis is in no way meant to imply that he agrees fully or in part with my particular assessment. You may want to seek his own professional opinion on the matter here on Twitter as I have found that he is both friendly and accessible.

Note: Official agencies issue burn warnings during dry times for a reason. Anyone lighting fires during such times of extreme dryness — like the present — represents a hazard to public safety. Health, property, the resiliency of our national forests, and individual livelihoods are all put at risk by careless, reckless or malicious use of fire under these circumstances. Please heed the guidance of local, state and national authorities in such instances.

Drought, Burning Rings of Fire out West, Severe Flooding in the East: How Climate Change and a Mangled Jet Stream Wrecked US Weather

Earlier this summer, I had a weather conversation with my mother. She was excited about a new business venture my sister had undertaken (Adventure Kayaks) and for an upcoming trip to Yosemite in August to celebrate her and my father’s 45th wedding anniversary. She wondered about the weather, hoping it would be a good summer for both the new business and the trip. Without thinking too much, I said:

‘Rain, cooler weather, and storms in the east, drought, heat and fires in the west.’

Immediately after saying this, I felt reticent. Perhaps I shouldn’t have spoken? Maybe I would scare my mom. What good would it do to ruin her enjoyment or her looking forward to both the trip and to my sister’s potential success?

It’s worth noting that, thankfully, the storms and cooler weather that did emerge with fury and flood in the east did not ruin my sister’s kayaking venture (although it did result in numerous interruptions both during spring and throughout summer). Should a tropical storm or hurricane make landfall on the US east coast this August, September or October, however, the devastation could be vast, perhaps exceeding a 1 billion dollar disaster event (more on this below).

But as my mother boarded her plane to California and a potential date with Yosemite yesterday morning, these were the satellite images I was looking at:

Yosemite Fire NASA Earth Observatory

Yosemite Fire NASA Earth Observatory

Image source: Earth Observatory

The vast Rim fire that had grown to consume over 192,000 acres as of today was steadily devouring the western border of Yosemite. You can see it on the above infrared satellite picture provided by NASA as a ring of bright white steadily inching into the indicated yellow border of Yosemite.

Jennifer Francis, Stu Ostro and How I Knew

Earlier this summer, my mother chided me on my ‘attempts to predict the weather.’ In a phone conversation last night, she asked ‘how did you know?’

It’s fair to say that in the overall prediction of more storms and rains in the US east, with more risk of flooding, and more heat and dryness out west, with more risks of fire, that I wasn’t entirely certain. However, I’d recently read the work of climatologist Jennifer Francis and had been listening to and following the statements of Stu Ostro. During early spring and summer, I observed a Jet Stream pattern setting up over the US that appeared to be settling into a ‘stuck position’ that would result in the high likelihood of the conditions I communicated with my mother. It’s worth noting that in looking at these Jet Stream patterns it’s not difficult to make such predictions because the patterns change slowly, they lumber and tend to remain stuck for long periods. Once a pattern settles into place, it’s a good bet that it will stick around for at least a few months these days, a fact that the models nail but which meteorologists, in general, have failed to communicate. In short, this is a climate change driven change in the weather.

In fact, some meteorologists and climatologists seem entirely reticent to accept this new weather pattern, despite the fact that it is a powerful tool for weather prediction and will tend to result in less surprises. The big troughs equal record floods sticking around for a long time and the big ridges equal record heat, drought, and probably fires sticking around for long periods of time.

In an example of this reticence, a recent paper by a University of Colorado researcher concluded that Jennifer Francis did not have enough evidence to support her claims of an observed slowing in the Jet Stream. Unfortunately, the paper included, as a part of its findings, a cross section of the atmosphere in which the Jet Stream does not typically reside even while the paper included a sample during which changes were already occurring, which would have likely biased its results. Despite these biases and errors, where the paper actually did measure Jet Stream flows, it corroborated Francis, showing Jet Stream slowing during the periods measured. This is odd considering the fact that the concluding statement contradicts the papers own findings, a point which Dr. Francis, herself, provides.

It’s easy to understand why reticence still lives in the science. As I noted above, it’s understandable to feel reticent when being the bearer of bad news. No one wants to be the messenger that gets metaphorically ‘killed.’ But without making use of the clear understanding provided by Francis and Ostro, we will continue to be surprised by extreme floods, storms, fires, heatwaves and droughts that can be easily predicted by simply looking at how the Jet Stream sets up and where it gets stuck. Instead, ‘surprise’ after ‘surprise’ just keeps coming our way.

When Rossby Waves Get Stuck: Changing to a More Radical Jet Stream

Dr. Jennifer Francis has observed that loss of sea ice and snow cover in the Northern Hemisphere has resulted in a slowing of the Jet Stream in recent years. Sea ice volume, the measure of total ice in the Arctic Ocean, since 1979 had declined by as much as 80% when measured at its low during 2012 (this measure may rally back to around 75 to 78 percent lower than 1979 this year, but the overall trend remains a death spiral). Greenland melt is unprecedented at 500 gigatons per year and with Arctic heatwaves blasting the tundra both permafrost and snow cover are at record and near record lows. 80 to 90 degree temperatures now often advance to the shores of the Arctic Ocean, with the coldest air pushed back above the 80 degree north latitude line, confining it to a shrinking region that, increasingly, huddles closer to the remaining large ice sheets in Greenland. Overall rates of warming for much of the Arctic are about .5 degrees C temperature increase each decade, more than twice the global average.

A more quickly warming Arctic results in changes to the atmosphere’s heat balance. According to Francis, the height of the atmosphere over the Arctic is rising relative to atmospheric heights in the lower lattitudes, this loss of slope results in lower gradients from north to south and since temperature, atmospheric height and pressure gradient drive Jet Stream speed, the Jet Stream slows down. And as the Jet Stream slows, it tends to seek out the highest gradients it can find. The result is more northward invasions of the polar region of the Jet Stream ridges and more southward invasion of the Jet Stream troughs. This amplification creates a rather large and elongated sine wave called a Rossby wave pattern.

Jet Stream Pattern Change. Image source: NOAA.

Jet Stream Pattern Change. Image source: NOAA.

In the sequence above, we see the progression of a flat Jet Stream to a Rossby wave ridge/trough configuration to, eventually, cut off lows and highs. In the past, such waves tended to set up for briefer periods, extending for days or weeks before returning to the usual, more flattened motion of the Jet. In more recent years, large Rossby type waves have been the typical pattern, one that transitions to cut off lows before it returns to a configuration more similar to (b) in the diagram, before setting up as a Rossby-type wave again.

Perhaps more importantly, this b, c, d progression has tended to occur again and again and again over the same geographical region for months and months on end. And, looking back at Jet Stream maps over the past months, this is exactly what we find.

Below is a progression of images I’m providing from this blog’s archive. It includes either direct temperature measures that indicate Jet Stream patterns or a mapping of air flow speed indicating the Jet Stream’s path.

Clover leaf Jet Stream Pattern April, 2013.

Clover leaf Jet Stream Pattern April, 2013.

(Image source: ECMWF)

In ‘For Central US, Climate Change and a Mangled Jet Stream Means Drought Follows Flood Follows Drought’ I described how the Jet Stream pattern had consistently switched from large trough to large ridge configurations over the past few years bringing either heatwaves and droughts or storms and floods. But the left hand portion of the image provides a good record of the Jet Stream configuration as of mid April this year. Following the temperatures, on the west coast we see a large, hot ridge and in the central and eastern US we see a deep, cool and stormy trough.

Wednesday July 3, Rossby wave still in effect over US.

Wednesday July 3, Rossby wave still in effect over US.

(Image source: ECMWF)

Throughout May and into June, this ridge over west, trough over east, pattern continued. By late June, a massive, record-shattering heatwave had set up over the US southwest. I described this highly anomalous event in ‘Mangled Jet Stream and Global Warming to Shatter Earth’s Highest Recorded Temperature This Week?’

Looking at the ECMWF image above we again see the highly exaggerated ridge/trough dichotomy setting up over the US with very hot, dry conditions out west and cooler, wet and stormy conditions in the east.

At this point, I want to tap Stu Ostro’s own observations to add to the Jennifer Francis mix. What Stu has found is that large, powerful high pressure systems have tended to develop more and more often. These extraordinarily dense systems seem to be exploding to new heights in a thickening atmosphere. Primarily, these monsters are driven by heat and so they tend to live in the massive ridges provided by our new, exaggerated and slowed, Jet Stream pattern. That said, these beasts can spring up almost anywhere there is a massive abundance of heat to tap, as one did over a super-heated region of ocean near Shanghai this summer sparking its own monstrous heat wave.

These large heat domes have major and far reaching effects. To understand them, we must first step back to think about the broader effects of human caused warming before looking at how heat domes manifest in the atmosphere. Based on models of the Earth’s atmosphere, we know that for each 1 degree Celsius of Earth temperature increase we get a corresponding 8% amplification of the hydrological cycle. What this means is that evaporation happens 8% faster and condensation happens 8% faster — OVERALL.

Since 1998, we have observed temperatures that are, on average, .8 degrees Celsius above those seen during the 1880s. What this means is that the hydrological cycle has amplified by 6% over this same time period. Because of this dynamic, droughts are more intense, but rainfall events are also more intense. Yet since the atmosphere is uneven we can expect this 6% amplification to manifest in somewhat more extreme fashion at the locations where more extreme Jet Stream patterns set up.

Mangled Jet Stream Dumps Deluge on US Midwest

Mangled Jet Stream Dumps Deluge on US Midwest

(Image source: California Regional Weather Server)

What goes up must come down. And that massive heat dome over the western US and Canada had been baking moisture out of the soil at unprecedented rates over an extended period from April to August. The moisture injected into the heat dome rose and rose, The high pressure system suppressed cloud formation so the moisture had no where to go but up and out. Eventually, this moisture found the edge of the massive high and spilled over into the storms riding along the Jet Stream trough rushing down from the Arctic Ocean and into eastern Canada and the US (hat tip to Colorado Bob).

The result was multiple flood events starting with the Midwest floods of April, then the massive Canadian floods (Calgary) of June, then the Toronto floods, then the Midwest floods of early August, and lastly the east coast floods of mid to late August. The Calgary floods were the worst ever recorded in Canada, the Toronto floods were the worst recorded for that region, and in the Midwest floods of early August, four months worth of rain fell in just one week.

Monthly rainfall estimates August 2013.

Monthly rainfall estimates August 2013.

(Image source: The Weather Channel)

On 8 August, the time of the second barrage of major Midwest floods this year, we find the Jet Stream in the same elongated configuration with a large northward ridge extending all the way from the southwestern US to the Arctic Ocean and with a deep trough diving back down into the central and eastern United States. As noted above, the mangled Jet Stream delivered its overburden of moisture directly to the US Midwest, dumping four months worth of rain in just one week.

A second pulse of moisture rode far south along this Jet Stream flow to dump massive amounts of rain over the southeastern US about a week after pummeling Missouri. This flow combined with a compromised tropical system to saturate the southeast, with some regions receiving as much as 300 percent their annual rainfall totals by late August.

One of the hardest hit areas is Lake Okeechobee. Water levels there as of mid August hit 16 feet at the Hoover Dike, a level that requires weekly monitoring for cracks or ruptures. The dike stretches over 140 miles along the perimeter of lake Okeechobee and was intended to keep the lake in check during major storms and hurricanes after large outburst events in the early 20th Century resulted in thousands of lives lost. The dike is 25 to 30 feet high and is as wide as a football field. The US Army Corps of Engineers has been working feverishly to shore up the dike in a project that will take years to complete.

At 16.5 feet water level, the dike will require daily monitoring. For each inch of increase above that level, the pressure put on the dike would greatly increase risks of catastrophic failure. The causes of such high water, this year, were neither tropical storms nor hurricanes. Florida has been, thus far, spared the wrath of these strong storms. Deep Jet Stream troughs and a constant Atlantic moisture flow have, instead, resulted in day after day rain events for much of southern Florida, pushing August totals near Lake Okeechobee above 16 inches, filling the massive lake and putting the dikes at risk. Should a hurricane or tropical storm strike Florida during late August, September, or October, the dike could overtop or rupture, unleashing the massive lake on communities sitting beneath it. (Hat tip to Colorado Bob).

As the threat of massive floods continued to increase in the east, the west was erupting with wildfires. Fire containment efforts went into high gear both exhausting the Forest Service Fire budget and briefly pushing the national fire alert level to 5. The Rim Fire, so close to my parents’ vacation site, expanded to 192,723 acres today making it the 6th worst in California history.

Rim Fire on August 28th, 2013

s Rim Fire on August 28th, 2013

(Image source: Lance-Modis)

You can see this massive fire, now 23% contained, burning to the west of Yosemite in the Modis shot below. A more detailed report of this major wildfire is provided by WeatherUnderground here and here.

Mangled Jet Stream Temporarily Edges Eastward

My parents wanted to see Yosemite’s amazing waterfalls. A major source of my reticence in telling them the likely pattern for this summer was that the heat and drought out west would probably dry out many of those magnificent falls. And, sadly, this has happened. So even if they brave the smoke and fires to reach Yosemite, the one attraction my mom had been most excited to see will likely be somewhat less magnificent.

But a cloud has suddenly appeared in this wrinkle. For the Jet Stream had edged slightly east.

As of the middle of last week, reports of heatwave conditions had emerged throughout the US Midwest with North Dakota, South Dakota, Nebraska, Illinois, Wisconsin, Iowa, Minnesota and Missouri experiencing temperatures in the range of 20 degrees (Fahrenheit) above average. With heat index values hitting as high as 110 degrees, communities sweltered and school systems declared closings. In California, where temperatures had remained in the upper 90s to lower 100s for much of summer, the trough advanced, pushing temperatures back down to the 70s. An upper level low flirting with the west coast may even toss a few fog clouds and rain showers toward California. Such an event would be a welcome change for both my parents and for beleaguered fire fighters in the region.

In any case, the shift is expected to be short lived with ECMWF models showing the Jet Stream again backing up and reforming a hot and dry ridge pattern over the US west. So the Midwest can expect cooling and a return to more stormy, rainy conditions while the US west, after only a brief respite, continues to bake:

Mangled Jet Stream Early September

(Image source: ECMWF)

The September 7 ECMWF forecast again shows a large and powerful Rossby-type wave pattern with a very large and hot ridge setting up over the US and Canadian West with a deep trough digging down toward the US East Coast. It is the same pattern we’ve seen since at least April, a pattern that has delivered numerous rounds of heat and drought to the US west and an equally vicious and persistent pattern of storms and flooding from the central US to the east coast. The Jet Stream has, essentially, been stuck these past 5 months and there is no end in sight. For even if this configuration of the Jet were to move, it would likely simply re-distribute the locations of heatwaves and droughts and storms and floods.

If anything, this past summer has been yet one more validation in evidence of the work of Dr. Francis. And it is because of her work that I, a relatively untrained observer, can make the accurate prediction that a large region from the Mississippi west to California will continue to stay hot and dry and will continue to see risk for large fires, while the region to the east will remain cooler and stormier so long as the current Jet Stream configuration continues to persist. The western region will risk periods of record heat, continued drying of lands, rivers and aquifers, and fires of record size. The eastern region will continue to risk record floods and storm events. As summer proceeds to fall, shifts in these weather patterns have the potential to grow violent with the possibility of powerful nor-easters or hybrid storms developing near the US East Coast. Both the southeast and Florida remain very vulnerable to continued large rain events or tropical storms and hurricanes as time moves forward and in the event of pattern persistence. Meanwhile, long range model forecasts show this general pattern continuing to persist until at least early to mid September.

At this point, the current US Jet Stream pattern will have been in place for at least 6 months.

 

 

 

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