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

Today the globe is feeling quite a bit of backlash from a human-warmed sea surface and atmosphere. As it ends up, Dr. Kevin Trenberth was right. Deep ocean warming set off by heat-trapping fossil fuel emissions and building up through the first two decades of the 21st Century did re-surge from the depths to haunt us in 2014, 2015 and 2016. In that wrenching global climate system shift to the hot side of natural variability, a titanic El Nino emerged. It was one of the top three strongest such events in the modern record. One that by NOAA’s measure appears to have tied the extreme event of 1998 at its peak intensity.

ONI sea surface temperature anomalies in Nino 3.4

(Sea surface temperature departure from average in the benchmark Nino 3.4 zone shows surface ocean heat anomalies for the 2015-2016 El Nino equaled peak 1997-1998 values. Image source: NOAA/CPC.)

Expected Heat, Drought, and Storms Together With a Few Ominous Surprises

This event did push the world into extreme warmth even as predicted related severe weather flared in some of the typical regions. Annual average global temperatures rocketed to about 1.06 C above 1880s baselines during 2015 even as monthly departures hit 1.2 to 1.3 C or more higher than the same benchmark during December and January.

Amidst this great upheaval of global heat, the world also experienced yet one more wave of freak droughts (this time over Northern South America, the Caribbean, large swaths of Africa and Southeast Asia), heat-related mass casualty events, floods, and strongest hurricanes on record. Arctic and global sea ice measures are once again plunging to new record lows. A global coral bleaching event, perhaps the worst such instance ever experienced, was also set in motion.

The predicted patterns and potential worse-case events (such as heatwave mass casualties, coral bleaching, and sea ice loss) were also contrasted by a number of surprises. The first and perhaps most ominous was the failure of El Nino to bust the California drought. Though the West Coast of the US did experience a number of storms, the pattern was more typical of normal Winter moisture for the Northwestern US even as drought continued throughout the Southwest.¬† Moisture instead tended to split fire-hose fashion — with storms either cycling northward into Alaska, the Aleutians, or the Bering Sea, or south over Southern Mexico or Central America, up across the Gulf and on out into a particularly severe storm zone forming in the North Atlantic.

30 day precipitation anomaly shows southwest drought continuing

(Over the last 30 days the southwest drought re-emerged as a blocking pattern again began to take hold over Western North America and the Eastern Pacific. Image source: NOAA/CPC.)

This continued loss of moisture for the US Southwest despite a record El Nino is particularly apparent in the Climate Prediction Center’s most recent precipitation anomaly measure for the last 30 days. Here we find that large parts of Central and Southern California have received just 10 to 50 percent of typical rainfall for this period. Coupled with 1-3 C above average temperatures for the month, this loss of rainfall during what would typically be California’s wettest period has come as a disappointment to many who were hoping a strong El Nino would help break the state out of a crippling drought. Now, the window for late Winter and early Spring rains is starting to close even as the blocking pattern appears to be strongly re-established in both the present weather pattern and in the forecast model runs.

But perhaps the biggest surprise coming from this El Nino year was a set of weather events in the North Atlantic that were likely more related to climate change. There, severe storms hammered a flood-beleaguered UK as a greatly distorted Jet Stream heaved Equatorial heat and moisture northward — rushing it up over a ridiculously warm and apparently backed-up Gulf Stream before slamming it on into a likely Greenland ice melt-outflow related cool pool. There the heat and moisture collided with cold to produce the epic storms that then vented their fury upon the UK.

Warm Arctic Storm

(December 29th saw temperatures rise above freezing at the North Pole — the first time temperatures have warmed so much for this high Arctic region so late in the year. Image source: Earth Nullschool.)

During one such event, a daisy chain of heavy-hitting North Atlantic lows hurled high winds, heavy rains and epic surf at the UK even as the meridional flow set up by these powerful beasts shoved above-freezing temperatures all the way to the North Pole during late December. Yet one more unprecedented and unexpected event during a record warm year. One that looks more like a human forced warming which has overcome the traditional influences of El Nino, rather than an El Nino related impact in itself.

As El Nino Fades, Equatorial Heat Tends to Move Pole-ward

Though we may see these two events — the failure of El Nino to provide heavy rains to the US West Coast, and the massive northward pulses of storms, heat and moisture hitting the North Atlantic — as unrelated, the twain patterns appear to be linked to an ongoing polar amplification. Overall, heat within the Arctic has tended to weaken the Northern Hemisphere Jet Stream over these two zones. And even during El Nino, when the Jet would have typically strengthened, we have continued to see high amplitude wave patterns forming over these regions.

But as El Nino weakens and the Equator cools, the Jet Stream would tend to slow even more. Such an atmospheric state would tend to further exaggerate already significant Jet Stream wave patterns — transferring still more low-Latitude heat poleward. In addition, the ocean gyres tend to speed up as El Nino fades or transitions to La Nina. The result is an amplified pulse of warmer waters emerging from southern Latitudes and entering the Arctic.

It’s for these combined reasons — tendency to amplify south to north atmospheric heat transfer into the Arctic post El Nino and tendency to flush warmer waters toward Arctic Ocean zones during the same period that it appears we are entering a high risk time for potential new sea ice melts and possible related Greenland land ice melts during 2016 and 2017.

Hot Blobs

(Northeastern Pacific Hot Blob remains at high intensity even as its size is predicted to expand through July. Meanwhile, very warm sea surface temperatures are predicted to remain in place off the Eastern Seaboard. The net effect of these two hot blobs may be to shove the Jet Stream far northward over North America during the summer of 2016 — potentially increasing the risk of widespread and potentially record heat and drought. Predicted very warm sea surfaces in the region of the Barents and Greenland seas — in excess of 3 C above average for a large region — is also cause for concern. This is not only due to risk for sea ice loss through this zone, but also due to its potential to set off blocking pattern and heat dome formation over Eastern Europe and Western Russia. Image source: NOAA/CFS.)

In addition, we are at serious risk of seeing the high amplitude blocks and wave patterns re-establish and persist, especially in the zone over Western North America were a related Northeastern Pacific Hot Blob is expected to restrengthen as El Nino fades. In fact, large regions of the US may fall under record to near record heat and drought this summer due to the combined influences of two very warm ocean zones surrounding her shores. Models now indicate a particular late spring drought risk for the Great Lakes region as well as an extended period of far above average temperatures for pretty much all of the Continental US during summer. Meanwhile, predicted above average spring-time precipitation for the Southwest appears less and less likely to emerge.

Finally, extreme above average sea surface temperatures are predicted to intensify over the Barents and Greenland seas through to end of Summer 2016. This is an area to watch. The added ocean heat would tend to pull the Jet Stream northward over Eastern Europe and Western Russia — generating risk of heatwaves and drought for this region even as Central Asia fell under risk of floods. Long range CFS precipitation and temperature model runs for Europe have not yet picked up this risk. However, given the intensity of heat predicted for Barents sea surfaces and the related tendency of warmth over oceans and in the far north to influence the formation of blocking patterns, heat domes, and high amplitude troughs, it’s worth keeping a weather eye on the situation.

El Nino to Weaken and Then Return; or is a Shift to La Nina Now Under Way?

Related to a polar and ocean warming-enhanced tendency to generate high amplitude Jet Stream waves — as well as associated persistent heatwaves, droughts, and floods — is the heat balance of the Equatorial Pacific. Strong El Ninos, or even a tendency to remain in or near an El Nino state, has historically aided in the breaking of new record global high temperatures when linking up to the greenhouse gas warming trend. Meanwhile, the shift toward La Nina has tended to enhance a range of global heating related issues including record rainfall events and large injections of heat toward the poles in the drop off from El Nino to La Nina.

The cause for increased risk of major precipitation events is due to the fact that El Nino is providing a massive moisture bleed into the atmosphere at times of peak intensity. With the current El Nino topping out near record levels and with global temperatures at above 1 C higher than 1880s averages, global atmospheric moisture levels are hitting new record highs at this time. If global temperatures subsequently drop by around 0.1 to 0.2 C during a transition into La Nina (into a range about 0.9 to 0.8 C hotter than 1880s values) then the atmosphere will be unable to keep a larger portion of that extra moisture in suspension and it will fall out as precipitation — primarily wringing out where the major trough zones tend to set up. We should be very clear here in saying that the drought risk related to a global warming intensification of ridge and heat dome formation is not reduced during such instances — just that the risk of extreme precipitation events is enhanced.

Russian Heatwave Pakistan Floods Jet Stream

(During 2011, as the 2010 El Nino faded into La Nina conditions, a high amplitude wave in the Jet Stream set off record heat, drought and wildfires over Russia even as Pakistan was hit by a month-long deluge that was the worst rainfall event for the region in the last 1,000 years. La Nina’s tendency to wring excess water out of the atmosphere can enhance the risk for such events to occur in a warming climate state. Image source: NASA.)

As for risks to sea ice, we’ve provided some of the explanation above. However, it’s also worth noting that the mobility of heat poleward tends to be enhanced during the periods when El Nino drops off toward La Nina. During these times, Equatorial heat tends to propagate in wave fashion toward the Poles — especially toward the Northern Hemisphere Pole which has already lost its strong Jet Stream protection warding away warm air invasions.

These two factors are major issues when considering whether La Nina or an ENSO Nuetral state will appear post El Nino during 2016. But there is a third — rate of global temperature rise. Though the primary driver of global warming is a massive human fossil fuel emission, the response of the world ocean system can significantly wag the rate of atmospheric temperature increases on a decadal time scale. If the ocean tendency is for La Nina, this would tend to somewhat suppress the overall decadal rate of temperature increase — and we saw this during the 2000s. But if the ocean tendency is to produce El Ninos (in a switch to a positive Pacific Decadal Oscillation, as appears to be happening now), then the overall pace of global atmospheric temperature increase would tend to be enhanced.

La Nina Emerges

( IRI/CPC consensus model runs show a drop off to a weak La Nina by late in the year. However, CFS model runs [image below] have shown a tendency to predict a resurgence of El Nino conditions by Fall. Image source: NOAA/CPC.)

To this point we find that the official model forecast consensus published by NOAA (IRI/CPC figure above) shows a transition to ENSO neutral states by May, June, and July which then proceeds on to a very weak La Nina by Fall. In such a drop off, we would likely still see record global high temperatures during the period of 2016 (in the range of 1.03 to 1.15 C above 1880s values).

However, the late 2016 and 2017 tendency for temperatures to recede from new record highs would be somewhat enhanced (likely dropping below the 1 C above 1880s mark in 2017 or 2018 before again making a challenge to the 2015-2016 record with the potential formation of a new El Nino in the 3-5 year time-frame of 2019 through 2021). It’s worth noting that this scenario shows an increased risk of a stronger warm air pulse heading toward the Northern Polar zone together with added fuel for extreme precipitation events as global temperatures would tend to drop off more swiftly from late 2015 and early 2016 peaks.

El Nino Continues

(CFSv2 model run — shows El Nino continuing on through the end of 2016. Over recent months, the CFSv2 series has shown a high accuracy. However, NOAA’s current forecast preference is for the IRI model set predictions [previous image above]. Image source: NOAA/CPC.)

In contrast, the CFSv2 model forecast from NOAA (above image) shows El Nino only weakening through to July and then re-strengthening in the October-November time-frame. This CFS model scenario would result in higher atmospheric temperatures in 2016 — practically guaranteeing a lock on an unprecedented three back-to-back-to-back record warm years for 2014, 2015, and 2016. But such a scenario — implying that the Pacific Ocean had entered a new period of El Nino tendency — would also tend to keep atmospheric temperatures nearer to the newly established record highs.

Under the CFSv2 scenario, we may expect annual average global temperatures to rise as high as 1.08 to 1.2 C above 1880s values during 2016 (a very extreme departure and one uncomfortably close to the 1.5 C warming mark). These extreme values would, perhaps, recede to around between 0.9 and 1.1 C during 2017 so long as the second El Nino pulse did not remain in place for too long. However, if the bounce back toward El Nino conditions was strong enough in late 2016, there would be an outside chance that the globe may experience not 3, but an absolutely obnoxious 4 back-to-back record warm years.

NASA temperature trend

(During 2015 global annual temperature rocketed to above 1 C hotter than 1880s values. There’s at least an even chance that 2016 will be hotter still. Considering the considerable heating tendency imposed by a fossil fuel-forced warming of the world, how much worse can it get during the 21st Century’s second decade? Image source: NASA GISS.)

Meanwhile, the warm air pulse heading toward the poles may be somewhat muted under this scenario. A statement that should be qualified by the fact that we’ve already seen a substantial amount of El Nino heat heading poleward during the present event. In addition, potentially heavy rainfall events may not receive the added oomph of a decent global temperature drop to wring out more moisture. A statement that requires the further qualification that overall atmospheric moisture loading is enhanced by rising global temperatures — so comparatively less heavy rainfall is a relative term here.

At this time, NOAA favors a transition to La Nina forecast stating:

“A transition to ENSO-neutral is likely during late Northern Hemisphere spring or early summer 2016, with a possible transition to La Nina conditions by fall.”

However, it’s worth re-iterating that the CFSv2 model forecasts have been quite accurate in predicting the path of the current record El Nino to date.

Links:

NOAA/CPC

NASA GISS

Hothouse Mass Casualty Event Strike Eqypt

Southern Hemisphere’s Strongest Storm on Record

Punishing Four Season Storm Grips US

A Monster Arctic Melt Season May Have Already Begun

Deep Ocean Warming is Coming Back to Haunt Us

Warm Arctic Storm to Unfreeze the North Pole

More Signs of Gulf Stream Slowdown as Floods Devastate Cumbria England

Deconstruction of Asia’s Wild Weather

Hat tip to Caroline

 

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For Arizona and New Mexico, Climate Change and a Mangled Jet Stream Means Fire Season Now Starts in February

Isleta-Pueblo-Fire

(500 acre wildfire burns near Isleta in New Mexico on February 19th. Image source: KOAT)

It’s late winter in Arizona and New Mexico. Or at least that’s what the calendar says. During this time of year, snow packs should grace the mountain peaks and cool breezes should blow down into the valleys. A train of west coast moisture should be riding over the mountains of California, bringing with it the occasional snow or rainstorm.

Not so this winter. The blocking pattern over the west coast has mostly held strong — pumping warm, dry air up from the southwest. This warm flood has resulted in continued severe drought conditions ranging from Texas through New Mexico, Arizona and Nevada. Most of California still reels under the worst drought seen in at least a century. While according to reports from the US Drought Monitor, New Mexico experienced its driest January on record. And though the 10 month long blocking pattern barring the Pacific moisture flow briefly fluttered in early February, it has since reasserted itself.

Drought monitor west February 18

(Drought Monitor showing 60% of the Western US suffering from some level of drought. Image source: United States Drought Monitor.)

The result, for Arizona and New Mexico, is unprecedented. For all across these states, weather conditions are pointing toward the beginning of an entirely different season. Humidity levels are excessively low. Temperatures are warm or abnormally warm. And abundant dessicated vegetation covers the hills and valleys. It is a set of conditions that usually don’t begin to ramp up until May. The season of burning and of combustive heat — fire season. In February.

0.1 Inches of Rainfall, Brush Fires Encroaching on Cities

One needn’t look too far to find causes for an early emerging fire hazard. The region of Tuscon, for example, only received a tenth of an inch of rainfall throughout the entire month of January. Throughout February, moisture levels have remained exceptionally low with relative humidity often ranging into the single digits. The result is that vegetation which briefly exploded during a period of abnormally intense rainfall this summer has become withered and dessicated, providing ample and highly combustible fuel should any ignition source emerge.

These are the conditions we should expect as a result of human caused climate change — very intense precipitation followed by very intense dryness along with Jet Stream patterns that tend to become stuck as Arctic sea ice loss and polar amplification in the Arctic accelerates.

Arizona New Mexico February

(Smoke from sporadic brush fires visible over regions of central and southern Arizona and New Mexico that are now virtually devoid of any snow pack, even in February. Image source: Lance-Modis/NASA.)

Even worse, the snow packs for the region, which for years have been steadily receding under a regime of increasing temperatures, are now practically non-existent. Snow pack usually aids in the suppression of ridge and mountain fires until late spring by locking in soil moisture, adding moisture to dry air, and creating runoff that is a natural barrier to fires. Not so for 2014 as there is simply no snow pack to speak of.

In addition to the 500 acre Isleta New Mexico fire, such dry conditions have already led to a spate of brush fires that have encroached on major cities in the region, prompting officials to warn of the, above mentioned, very early start to fire season. According to reports from the Arizona Daily Star:

The recent warm weather, dry conditions and a spate of brush fires on the outskirts of major cities of Arizona and New Mexico are prompting warnings that the 2014 wildfire season is already underway.

The result is that fire warnings have been raised as tinder-box conditions of low humidity, temperatures ranging into the upper 70s, strong winds, and amply abundant fuel persist and intensify. And given that the fire risk began in February, we can expect a very, very long fire season ahead.

Winter Fires Ranged from California to the Arctic in 2014

Unfortunately, Arizona and New Mexico were not the only regions suffering from winter fire seasons during early 2014. California, suffering its worst period of drought in at least 100 years, saw a set of powerful fires rage through Colby near Los Angeles in January. Meanwhile, freakish fires burned near the Arctic Circle in Norway just a week later. Now Arizona and New Mexico add an initiation of fire season in February to the unprecedented tally.

Links:

Fire Season Already Underway in Arizona

Isleta Fire Now 466 Acres

United States Drought Monitor

Lance-Modis/NASA

2000 Acre Colby Fire Rages Near Los Angeles in Winter

Arctic Wildfires in Winter

Hat tip to Collapse of Industrial Civilization

Hat tip to Miep

Blocking Patterns: Rivers of Moisture to Converge in Major Rain Event For Eastern US?

Water Vapor July 2

(Image source: GOES/NOAA)

Today, a very muscular blocking high pressure system located over the Western US flexed. After having set off record fires and heat waves it reached deep into the Arctic and drew moisture and more unstable air down from over Hudson Bay across the Rockies and over top of Arizona and New Mexico, igniting powerful thunderstorms which blanketed large areas in hail, heavy rainfall and lightning. A second moisture stream drawn into the high’s circulation from the Pacific also fed these storms.

You can see the bright, high, cold cloud tops now firing over Arizona and New Mexico.

To the east, an upper level low pressure system is just now starting to draw this concentrated moisture into two other feeding, damp air flows. The largest draws straight up from the Caribbean over Florida and then rushes up the US East Coast. The second, pulls moisture from tropical storm Dalila in the Pacific, draws it over Mexico, then pulls it over Mississippi and up the back side of the Appalachians.

The action of this powerful blocking high over the US West and associated upper level  low over the East is likely to result in very moist, rainy conditions for a large section of the country east of the Mississippi River. On the Gulf Coast, as much as 5-8 inches of rain is expected. But a wide swath shows potentials for 1-5 inches over the coming week.

This persistent wet and extremely moist flow raises the risk of flash flood conditions where major storms light off. Record rainfall over many areas has already left the ground saturated and atmospheric conditions are very unstable, setting off the potential for powerful storms.

The broad sweep of these convergent moisture flows also sets up the possibility that even more violent conditions may emerge. Large blocking highs were associated in all the major flood events that have occurred around the world so far this year. In one example, noted by commenter Colorado Bob, Pakistan suffered 120 degree heat under a blocking high during May and June. The high then swept a massive flood of moisture up over India and into the Himalayas. The result there was devastating floods that left hundreds dead in a virtual tsunami of mud and water.

The strength of the current upper level pattern, drawing moisture from the Arctic, the Pacific, a tropical weather system, and from the Caribbean sets in place the components for major instability to meet with four rivers of moisture over the Eastern US. It’s a dangerous set of circumstances that may result in current rainfall forecasts under-shooting long-term totals. This week has already seen a number of torrential downpours over broad sections of the US East Coast. But this flow taps even more moisture than what was previously in place, drawing from multiple sources across an area spanning more than 4,000 miles to link rivers of moisture with unstable air. Let’s hope these convergent flows don’t set off flood events similar to those seen in Europe and India this year.

Fair warning: the mangled Jet Stream now has the Eastern US under the gun.

(Hat tip to X-Ray Mike for his comments on strange storms in Arizona today).

 

For Central US, Climate Change and a Mangled Jet Stream Means Drought Follows Flood Follows Drought

 

In 2011, a historic drought severely impacted Texas. Shortly after, record floods hit the central US, pushing the Mississippi and its tributaries to record high levels while ending the Texas drought. One year later, a 55 year drought hit the heartland of the US pushing the Mississippi back to record low levels in many regions.

Enter April 2013 and the weather has once more swung back to the flood extreme of what appears to be a new Drought, Flood, Drought paradigm. This winter, unusually heavy precipitation created a much larger than normal snowpack for the north-central US. Then, in April, warmer weather and a series of heavy rain events combined to push the Mississippi River and its tributaries from record low levels to record and near record high flood stage in many locations.

Now, along the Mississippi and its tributaries, flood gauges are recording moderate to severe flooding at over 60 stations. But this selective dump of large volumes of precipitation over the Mississippi River valley has still left much of the western US in the grips of drought. In fact, 47% of the contiguous US is still suffering from drought even as many places in the Heartland flood.

How can this happen? How can historic and opposite weather extremes such as severe drought and flood repeatedly affect the same region year after year? The answer lies in a re-currence of powerful blocking patterns that keep the polar jet stream in a fixed position for longer periods of time. The result is that weather in a given region tends to persist for longer and longer periods. So if weather gets stuck in a hot and dry pattern, as it did from April to December of 2012, then severe heat waves and drought conditions are most likely to follow. And if the jet stream switches back to a position where it plunges down from the Arctic, expect a long period of cooler and much wetter, stormier conditions, as the Central US experienced January to April of 2013 and which has resulted in the current major flood events.

Looking at the ECMWF weather model forecast for Friday, May 3rd, we can see a persistence of the cool, stormy, wet pattern continuing for the Central US.

Cold air jet

Notice that long tongue of colder air plunging down all the way from northern Canada, through the central US and down into Texas? Sweeping along the trough is a low which will likely bring even more rain to flood-stricken areas later this week. This is the basic pattern that has persisted for the central US all throughout 2013. And the result is more cool air, more storms, and more precipitation for that region persisting for weeks and months on end.

If we look to the west of this cold, wet trough zone, we can find its culprit. A blocking high pressure system that has parked itself just west of the US and Canadian Pacific coasts since this past January. This high is pulling warm, drier air up from the south. It is responsible for persisting drought conditions for the western US. And it is responsible for a big northward bulge in the polar jet stream running up over west-central Canada before an equally exaggerated southward swoop plunges down into the central US.

Classic blocking pattern.

Now, if we rewind to last year, we find an opposite jet stream configuration emerging as a result of a powerful blocking high pressure system forming directly over the central US and bringing record hot temperatures over a broad region. It is the increasingly frequent emergence of these powerful blocking systems that are keeping the weather in a drought-flood bipolarization for the central US.

A growing number of climate scientists led by Jennifer Francis are attributing the greater frequency of blocking patterns and associated extreme weather events to the massive loss of Arctic sea ice since 1979. Overall, 80% of Arctic sea ice volume has been lost at end of Summer over the last 33 years. These climate scientists make a compelling observation that this ice which once trapped cold air to the north and kept warmer air confined to the south, has lost its insulating properties. Now, more warm air invades the Arctic even as more of the Arctic’s colder air tends to seep out into the mid-latitudes. The result is that the polar jet stream, which is powered by north-south temperature differences, both moves slower and forms the large, persistent, blocking wave patterns.

Such a climate regime of more persistent patterns of either extreme wet, cold, stormy weather or extreme warm, dry, drought conditions is likely to amplify as sea ice continues to recede and melt out. These conditions will probably worsen until glacial melt from Greenland reaches a tipping point. Once this tipping point is reached, cold ice bergs will invade the North Atlantic, pushing the cold air pole south and concentrating much colder air around the region of Greenland and the North Atlantic. At the same time that the North Atlantic becomes colder, the tropics become warmer. The result is a rapid acceleration of the polar jet in the region of the Atlantic Ocean. The large temperature differentials caused by this new climate state are likely to drive very powerful storms. It was the potential for such conditions to emerge by or after the mid 21rst Century that inspired Dr. James Hansen to write his ground breaking book “The Storms of My Grandchildren.”

After the current blocking pattern regime switches to the rapid Greenland ice melt regime, Dr. Hansen warns of the potential for ‘continent size frontal storms that pack the strength of hurricanes.’ Such storms would make Sandy seem like kitten’s play.

How do we avoid a continued worsening and more extreme climate? Simple. Stop emitting CO2 into the atmosphere. The sooner CO2 emission reduction and elimination policies are put into place, the less likely the very worst weather changes will emerge. But, until we make the wise, rational choice of CO2 reduction and elimination, we consign ourselves to what is most likely to be a decadal period of worsening and more extreme weather.

Links:

ECMWF

Wild Weather Extremes May Be Sign of Climate Change

In Midwest, Drought Gives Way to Flood

Rain-soaked Midwest Braces for More Flooding

Blocking Patterns: Cool Air Down South Means a Heatwave in Greenland

Global warming has mangled the Northern hemisphere’s weather. No clearer indication of this is the fact that currently, where I’m sitting in Gaithersburg, MD it’s 48 degrees Fahrenheit. Now let’s jump northward. Way north. North of the Arctic Circle north. So far north that only tens of miles away rests a glacier hundreds of meters thick.

That’s right, we’re talking about Greenland. Nuuk, Greenland to be specific. What’s the temperature there currently at 3:51 PM, Gaithersburg time?

48 degrees Fahrenheit.

The fact that two places separated so far north and south can experience practically the same weather is a perfect illustration of what global warming combined with Arctic sea ice melt has done to our weather patterns. Currently, a powerful blocking pattern and a very wavy jet stream is plunging far to the south and into the eastern United States. That jet stream has origins in the Arctic, so it is currently involved in cooling down Gaithersburg, Maryland.

The jet currently running down over the eastern US drinks deep of warmer temperate and tropical air before making a hairpin turn to the north, it travels up over the Atlantic Ocean, keeps making its way north until, at last, it comes to Greenland, depositing 48 degree Gaitherburg air directly over where it should be freezing in Nuuk.

That 48 degree temperature is a veritable heatwave for Nuuk at this time of year. The average daily high for this date is 26 degrees Fahrenheit. Nuuk’s high for today is 22 degrees warmer than it should be. And it’s not just today. For much of the winter Greenland has been far, far hotter than usual. The below graph, provided by NSIDC shows average temperatures for the Nuuk region of Greenland being about 5 degrees Fahrenheit or 3.3 degrees Celsius above average for the entire period.

Greenland temps NSIDC

(Image source: NSIDC)

Persistent warmer temperatures for Greenland have been a typical result of the new, global warming spawned weather pattern. It is this weather pattern that resulted in a major melt event for Greenland last summer. One that wrecked infrastructure there and contributed mightily to a 1 cm rise in sea level in just one year. Well, that blocking pattern is still in place. Going into the spring/summer of 2013, the weather is still stuck in a much hotter than usual mode for Greenland. If it continues, it will likely mean both more glacial melt and more extreme weather.

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