PAC 2013 Redux? Warm Storm Returns to Haunt Central Arctic

It's back. New Persistent Arctic Cyclone forms over Laptev Sea.

It’s back. New Persistent Arctic Cyclone forms over Laptev Sea.

(Image source: DMI)

Earlier this week, a moderate-strength Arctic Cyclone formed near Svalbard. Since that time it has persisted even as it drifted into the Laptev sea as a 1000 mb low today. Now, according to forecasts, the storm threatens to remain in the region for at least the next ten days, deepening to as strong as 980 mb and chewing into a region of sea ice that has been consistently weakened by storms since late May.

If you’ve followed this blog and feel you’ve heard this story before, it’s because you have. PAC#1 formed in late May and churned through the central sea ice all throughout June, creating anomalous thinning of a region near the North Pole and on toward the Laptev sea. By early July, the storm had finally petered out, but not after leaving behind a wreckage of thinned and broken sea ice.

Now, it appears a second storm (PAC 2013 #2) is set to churn through the same regions so drastically impacted by PAC 2013 #1, this time lasting for at least two weeks.

So here we go again:

PAC 2013 #2 Over Beaufort Sea

PAC 2013 #2 Over Beaufort Sea as 980 mb low on July 24th.

(Image source: ECMWF)

The above image shows a strong 980 mb PAC 2013 #2 over the Beaufort Sea on July 24th. Current model runs show the storm moving back and forth over the Central Arctic, Beaufort and East Siberian Seas until at least July 29th.

Warm Storm Takes Hold

As sea ice is much thinner and as atmospheric and ocean temperatures are much warmer, it is likely that a new Persistent Arctic Cyclone will have even more obvious and far-reaching effects than the one we witnessed in June. Average surface atmospheric temperatures throughout the Arctic are above the temperature at which ocean water freezes and almost all regions show temperatures above 0 degrees Celsius. So precipitation in these storm events is more and more likely to fall as rain.

You can view how much the Arctic has warmed in the composite weather map below:

Arctic Temperatures July 19

(Image source: Uni Koeln)

Note the large pulse of 78-86 degree (Fahrenheit) weather (24-30 degree Celsius) pushing all the way to the Kara Sea near Archangel and points eastward. Meanwhile, 40-50 degree (Fahrenheit) temperatures have become common in areas near Svalbard, the extreme north coast of Greenland, and even during the daytime over some sections of the Beaufort (not visible in the current shot above). We can also see a number of wildfires raging in the heatwave stricken region of Arctic Russia (fire sites on the map are indicated by vertical black lines with squiggles on top).

Overall, temperatures over the Arctic Ocean have averaged 1-3 degrees Celsius above normal. With most of the summer spent in cloudy, stormy conditions that usually lead to cooler weather, this year is highly, highly anomalous. What we have, instead, are warm storm conditions.

With all this heat in place, wet, rainy precipitation is much more likely to fall over areas of the Central Arctic underneath the new storm. As water carries more heat energy than air, a warmer than freezing rainfall over the ice sheet is a powerful melt enhancer. In addition, associated winds are likely to further shatter and disassociate ice beneath it. Eckman pumping forces will also be more likely to access warmer waters beneath the colder, fresher layer that tends to protect the ice. This is due to the fact that a constant sunlight has now streamed through the ice for two and half months running. This long duration sunlight is likely to create a warmer water layer in a range of 40-70 feet beneath the surface. A passing storm of moderate to strong intensity will likely be able to access this warmer layer and transport it to the surface where it can do work melting ice.

I took a look at a worst case warm storm scenario back in June that may provide a helpful, if extreme, example of these forces at work.

A somewhat stark example of what a warm storm can do to thin, fragile sea ice is also now plainly visible via APL’s North Pole Camera #2. Even since yesterday we can see that melting has rapidly advanced around the camera as it now rests in a deepening and expanding melt lake stretching far about in all directions:

Camera 2 now in icy water.

Camera 2 now in icy water.

(Image source: APL)

From this shot, only a small band of remaining snow cover now surrounds the buoy in the foreground. It also appears that the camera itself is now sitting in the water. It is worth noting that this melt lake currently rests on ice that is probably between 1 and 2 meters in thickness. But the waters now covering the ice are darker, absorbing more direct and indirect sunlight even as the above-freezing melt lake slowly bores down into the ice. If the Eckman pumping forces engaged by this storm are also bringing warmer waters up from the depths, the ice near this camera is suffering melt from both above and below.

Though the current picture shows somewhat sunny weather, conditions near the camera have been mostly stormy for the past three days. It is likely that storm conditions will soon return as this region is mostly engulfed in cloud.

Sea Ice Measures Near Record Lows

Sea ice area takes a vertical nose dive losing 400,000 square kilometers over the past two days.

Sea ice area takes a vertical nose dive losing 400,000 square kilometers over the past two days.

(Data Source: NSIDC, Image source: Pogoda i Klimat)

Major sea ice monitors now show ice area, extent and volume all falling rapidly. Sea ice extent, according to NSIDC is at about 7.8 million square kilometers — or 4th lowest on record. Cryosphere Today also shows sea ice area tied for 4th lowest on record with about 5.5 million square kilometers of sea ice area remaining. Area losses in this measure have been particularly cliff-like with nearly 400,000 square kilometers lost in just two days. Similar losses over the next 5-6 days would bring the monitor into new record low territory. By mid June, PIOMAS showed the sea ice volume measure running at about 3rd lowest on record with rapid losses ongoing since late May.

Though these values still remain above record lows, there is a huge amount of heat energy moving around in the Arctic. Earlier this year, the sudden amplification of the heat in May led to the fastest snow melt on record. Snow cover at the end of April was 9th highest. By the end of May, snow cover levels had plummeted to 3rd lowest. The fact that the Arctic is capable of such dramatic swings is clear proof that the heat balance there has reached highly unstable levels. It is for these reasons that we must remain alert for the potential of rapid ice loss as July transitions into August.

Despite a slow early May sea ice melt (in contrast to a racing snow melt), rates of loss have been near record levels throughout June and July of 2013. Given this break-neck melt pace and a state of continued fragility throughout the ice pack, risk remains high that one or more measures will see new record lows come September. Sea ice is now also very highly dispersed making it even more vulnerable to melt and disruption. The most recent Crysophere Today shot shows broad regions where sea ice concentration is now 60% or less.

Cryosphere Today

(Image source. Cryosphere Today)

With such broad areas of ice so vulnerable and exposed, any further thinning, melt and dispersal caused by the re-emergence of a warm storm is likely have strong impacts with the potential to dramatically affect final melt totals.

Links:

Persistent Arctic Cyclone and the ‘Warm Storm’ of 2013

DMI

ECMWF

Uni Koeln

APL

Cryosphere Today

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Arctic Heatwave Sizzles Northeastern Europe With 92 Degree Temperatures, Mangled Jet Stream Hosts Record Canadian Floods, and the Persistent Arctic Cyclone is Coring Through the North Pole

It’s your typical abnormal summer day in the Arctic. The Arctic heatwave flares again, Canada tries to recover from violent record floods, and a Persistent Arctic Cyclone that began in late May is continuing to core a hole through the sea ice near the North Pole.

The Arctic Heatwave Moves to Eastern Europe

An Arctic heatwave that has skipped from Scandinavia to Alaska to Central Siberia, pushing temperatures in this polar region into the 80s and 90s (Fahrenheit), has now re-emerged to plague Eastern Europe. Temperatures in the middle 80s are once again emerging in Finland, an area that blazed with anomalous 80 degree temperatures in early June. But areas north of the Arctic Circle in nearby Russia are, this time, receiving the real baking. There, highs in the region of Archangel, near the Arctic Ocean, reached 92 degrees Fahrenheit. Out over the Kara Sea, just north of these record-hot conditions, an area still choked with sea ice experienced near 70 degree temperatures today.

Average temperatures for most of these regions range from the 40s to the 60s. So current conditions are about 20 to, in some cases, nearly 30 degrees above average.

Arctic Heatwave June 24

(Image source: Uni Koeln)

In the above weather map, provided by Uni Koeln, we can see today’s record high temperatures showing up in pink in the lower right-hand corner of the map. Note the instances of 32 and even 34 degree Celsius temperatures (which converts to 90 and 92 degrees Fahrenheit respectively).

We can also see that some of last week’s fires over Siberia, which I described here, have been put out by a massive rainstorm now dousing the region. The storm emerged as a trough surged down from the Arctic and over Siberia, setting off large storms.

Extreme Jet Stream Sets Off Floods in Canada, Forcing 100,000 to Evacuate

During the middle of last week, the convergence of two upper-level flows of the Jet Stream set off very unstable conditions over Alberta, Canada. A cut-off upper level low stalled, trapped beneath a long-period blocking pattern and dumped rain on Alberta and regions of Central Canada from Wednesday through Monday. Consistent moderate-to-heavy rainfall fell in some areas for up to 16 hours without stop. By the weekend, many places had set one day records as a swath of 2 to 7 inch rainfall blanketed a broad region. Many areas, including Calgary, received their highest rainfall totals ever recorded.

Contributing to the problem was hard, frozen ground and ongoing mountain melt filling up streams and rivers. This combination of impenetrable ground, snow melt, and ongoing, record rainfall resulted in massive floods that turned streams into torrents, roads into rapids, and stadiums into lakes. In total, more than 100,000 people were forced to abandon their homes.

This particular event is likely to see damages well in excess of 1 billion dollars and could rival the record 22 billion dollar floods that rocked Europe just last month. Jeff Masters, at WeatherUnderGround, speculates that the 2013 Canadian floods may be the most costly in that country’s history. Given the massive impact of this major flood, damage totals may exceed previous record flood impacts, at around 800 million, by well more than an order of magnitude.

Persistent Arctic Cyclone Cutting Through the Central Sea Ice

PAC 2013 June 24

(Image source: DMI)

Lastly, a Persistent Arctic Cyclone that began in late May, and has now composed numerous storms remaining in place over the Central Arctic for about a month, continues to cut a hole into the sea ice near the North Pole. The above image, provided by DMI, shows PAC composed of an old low near the Canadian Archipelago and a new, stronger low that just entered the Central Arctic.

Lowest pressures are now about 990 mb, which is somewhat stronger than the storm that lingered over the Arctic this weekend.

Impacts to central sea ice appear to be ongoing even as somewhat rapid edge melt continues. The latest model assessment and forecast from the US Navy shows a widening and thinning area of broken ice near the North Pole, one that displays much greater losses than those seen earlier in the month. A band of open or nearly open water has now emerged just on the Russian side of the 180 degree East line. As you can see, model forecasts show this area of open water continuing to widen over this coming week.

PAC2013modelforecastJul1

(Image source: US Navy)

Meanwhile, some of the thickest sea ice is also showing the corrosive impacts of these ongoing storms. In the image above, you can clearly see the invasion of ice thinner than 2 meters where 2.5, 3, and 3.5 meter ice previously dominated. In fact, in later sequences, it appears that a knife of much thinner ice begins to drive down through the relatively small pack of remaining thick ice.

The Central Arctic is extraordinarily cloudy today. So it is not possible to verify these Navy observations with visual shots. That said, the Navy projections have been both consistent and confirmed in the other monitors since early-to-mid June.

****

Any one of these extreme weather events — a heatwave in Arctic Europe, immense floods never before seen in Canada, and an anomalous storm coring through the thickest sea ice — would be evidence that human caused climate change has radically altered the weather. Instead, we have all three occurring over the span of as many days. It is a pace of extreme events that is both troubling and astounding. And each has been affected by the sea ice loss, ocean, ice sheet, and atmospheric warming, loss of summer snow cover, and extreme changes to the circum-polar Jet Stream brought about by human caused climate change.

We are in the age of extreme weather brought on by our fossil fuel use. If we are to have any hope of preventing the very worst impacts, we need to drastically begin reducing CO2 and related greenhouse gas emissions as soon as possible.

Links:

Calgary Flood May be Most Expensive In Canadian History

Uni Koeln

DMI

US Navy

PAC 2013, The Month-Long Arctic Cyclone: Transitioning to a Warm Storm?

PAC2013Jun21

(Image source: DMI)

Well, it’s official. PAC 2013 has yet to give up the ghost. After transitioning to the Canadian Archipelago, it has now formed a trough composing three low pressure centers that roughly straddles Greenland, Baffin Bay, and the thickest sea ice. At this point, the storm is nearly one month old (with a formation date around May 21-26). Lowest pressures appear to be around 990 mb, but the entire region is covered in rough weather and clouds.

A look at the heat map shows the storm pulling in warmer air from the Alaskan side of the Arctic and from regions around it. This extra energy has given it enough to fuel multiple lows for an extended period. As a by-product, many regions over the Central Arctic are now above freezing. Areas near the low pressure centers still show temperatures in the range of 0 to -3 Celsius. But a broad swath of above-freezing temperatures are now under the circulation of this, rather large, storm.

PAC2013TempJun21

(Image source: DMI)

On the map, we also notice areas of high heat concentration centered over Scandinavia, Central Siberia, Alaska, and just West of Hudson Bay. These regions of heat are both potential launching pads for more warm air invasions of the Arctic as well as feeding sources for our storm, should it continue.

And, according to forecasts, we can find that this storm isn’t done by a long-shot. ECMWF model runs show it forming troughs with numerous low pressure cells and chewing through large portions of the Arctic all the way through to July 1. Seems we were right to caution against an end to PAC 2013 in this earlier blog.

A very interesting example is the ECMWF forecast for June 27th when PAC 2013 forms a sprawling trough from the East Siberian Sea to Baffin Bay to Greenland to the Kara. It is a trough composed of not one, not two, but at least six separate low pressure cells. The forecast for tomorrow through much of the model run shows similar configurations with daisy chains of storms linked by a trough swirling along through the Arctic.

Six Lows PAC 2013

(Image source: ECMWF)

These model runs would seem to indication very stormy conditions not only for the Central Arctic, but for the periphery as well.

The ‘Warm’ Arctic Storm Begins to Emerge?

With temperatures rising to above freezing in the Central Arctic Basin and with storms projected to persist at least until July 1rst, we may receive an unwelcome glimpse of the ‘Warm’ Storm described here. Previously, I had speculated that ‘Warm’ Storm conditions would be present with moderate-to-strong cyclones persisting in the Central Arctic at a time when air temperatures ranged from 0 to 6 degrees Celsius. As we can see from the temperature map at the top of the post, we are not far off from that threshold now. And with heatwaves popping up around the Arctic there is more than enough warmth to push Central Arctic temperatures higher over the coming days and weeks.

Over at the Arctic Ice Blog (read it, join it, follow it, chat on it — you will learn boatloads), expert posters Wayne and R. Gates have noted that while clouds block direct sunlight, they can act to trap long-wave radiation. R. Gates had also linked a recent scientific study which showed that cloudy conditions from March to May enhanced rather than inhibited melt. The energy of this long-wave radiation would transfer directly to ice and ocean, so atmospheric temperatures would not be directly impacted. But more heat content in the waters and ice, overall, might be providing some of the extra kick that ECMWF appears to have missed. Another recent study by Edward Hanna found that low level clouds helped to increase the record Greenland ice sheet melt of 2012 (study here) by trapping heat near the ice. So the overall effect of clouds in cooling is less certain than one would think at first blush.

Another source of this extra heat may be via the ocean itself. As noted in previous posts, cyclonic action creates a kind of pumping force (Ekman), that can pull water up from the ocean’s depths. In the Arctic, the surface layer is cold. But underneath lies a layer of warm water fueled by the inflow from oceans surrounding the Arctic (primarily the Atlantic). As commenter Johnm33 noted, once a strong inflow of upwelling water is established, it is possible that yet more warm water is being drawn into the deep Arctic Ocean from the Atlantic. If this warmer inflow was pumped to the surface, it would add to atmospheric heat beneath the storm.

Lastly, the atmosphere, via high amplitude waves in the Jet Stream is now also providing its own source of heat by dredging deep into the lower latitudes and pulling warmer air up into the Arctic. So far this summer, we have seen record heat waves in both Scandinavia and Alaska. These heat waves were caused by persistent blocking patterns that injected heat into these Arctic locations. Scandinavia saw temperatures in the 80s, Alaska saw temperatures rocketing into the upper 90s. The Jet Stream configuration allowing for these hot air injections at these locations still persists and are plainly visible on the current Jet Stream map:

Mangled Jet Jun21

(Image source: California Regional Weather Service)

Note the large wave in the Jet Stream (and associated warmer air) now riding up over Alaska and deep into the Beaufort, Chukchi, and East Siberian Seas. Another pulse is visible lunging up through Scandinavia. A third, though less southwardly linked, pulse is also now rising over Eastern Siberia. These extraordinarily high amplitude waves all cross far beyond the Arctic Circle. An atmospheric condition that is anything but normal and one that is also continuing to supply warmer air to the Arctic environment, even one covered by a storm that would normally substantially cool the atmosphere there (for more information on how snow and ice melt in the Arctic is enabling these high amplitude Jet Stream waves, take a look at some of the work of Dr Jennifer Francis). Instead, as the discrepancy with ECMWF predictions and surface observations shows, we have temperatures that are only .5 to 1 degree C cooler than average under the storm (they should be about 3-7 C cooler) and much, much warmer conditions surrounding it.

A Warm Storm persisting in the Central Arctic for long periods is a potential nightmare scenario for sea ice melt. Currently, we have warming conditions in the Central Arctic, a spate of record heat-waves at the periphery in places like Alaska and Scandinavia, a mangled Jet Stream that keeps pumping warmer air into the Arctic, and a storm that is now projected to persist until at least July 1rst. So we now have to consider at least the temporary emergence of the Warm Storm to be a possibility going forward.

Impacts to Sea Ice Still Ongoing, Likely to Ramp Up

A substantial thinning and chopping up of the sea ice is now apparent in all visible (when you can see through the clouds), concentration, and thickness monitors. Now, a wasteland of thinned, shattered and broken ice is visible in a swath from Svalbard all the way to Wrangle Island near the Bering Strait. A comprehensive graphic summary of these impacts is provided below:

PAC2013USNavyJun21Thinner

(Image source: US Navy)

The current image, provided by the US Navy is a stark contrast to conditions seen at the end of May. This thickness measure shows a long ‘claw’ of much thinner ice reaching all the way in to the Central Arctic and encompassing the North Pole. This graphic reveals very poor Central Ice thickness conditions for mid-to-late June.

USNAVYConcentrationPAC2013

(Image source: US Navy)

The US Navy surface concentration graphic also reveals very broken conditions for the Central Arctic in mid-to-late June.

UniBremanPAC2013

(Image source: Uni Bremen)

Uni-Bremen has been providing consistent confirmation of ice damage and fragmentation due to the Ongoing Arctic Storm for nearly two weeks now. Here’s the most recent concentration monitor showing the broad swath of broken ice.

Cryosphere Today PAC2013

(Image source: Cryosphere Today)

And Cryosphere Today, which is less sensitive than the other monitors shows low ice concentrations stretching from Svalbard to Wrangle Island.

Overall, should PAC 2013 continue to warm even as it persists, it should have ever-greater deleterious effects on the Central Arctic sea ice as mid-to-late June transitions into July. The US Navy thickness forecast shows ongoing thinning and fracturing in this region all the way through June 28th. One interesting feature of note in this forecast is that it appears a substantial section of ice will be separated from the main pack and stranded in the Kara Sea if current trends continue through early July.

PACUSNAVYforecastJun28

(Image source: US Navy)

The Storm That Just Won’t Quit

So, apparently against all odds, PAC 2013 continues and, even worse, shows risk of beginning a transition to a ‘Warm’ Storm in the Central Arctic. Should this trend remain in effect, increasingly visible damage to the central ice is likely to become ever more apparent as June turns to July.

Links:

DMI

ECMWF

US Navy

Cryosphere Today

Uni Bremen

Neven’s Arctic Ice Blog

California Regional Weather Service

Jennifer Francis Explains How Sea Ice and Snow Melt impact the Jet Stream

The Warm Arctic Storm

A Farewell to The Persistent Arctic Cyclone of 2013? Models Say Not Until June 22nd.

Today, the center of 2013’s Persistent Arctic Cyclone of May and June transitioned to Baffin Bay and the Canadian Archipelago. Forecast models show the storm lingering there over the next 24 hours, then briefly redeveloping in the Central Arctic on Thursday and Friday before finally transitioning on out of Baffin Bay by Sunday. If this forecast holds true, a storm that developed in late May and persisted to fracture and melt a broad swath of sea ice from Svalbard to the East Siberian Sea, will finally be done.

PAC 2013 Baffin Bay

(PAC 2013 over the Canadian Archipelago and North Baffin Bay on June 18. Image source: DMI)

The storm’s legacy, should it transition away from the Central Arctic as forecast, will likely leave impacts throughout this summer and beyond. The large area of fragmented and thinned ice left in the wake of PAC 2013 is more vulnerable to melt as June, July, and August progress. And a controversy among scientists, researchers, and Arctic and climate enthusiasts over if and how much PAC impacted the 2013 melt season is also likely to ensue, perhaps lasting for years after this melt season.

Already, a number of excellent blog posts on the subject of PAC 2013 have been published. Two that are certainly worth reading appear over at the Arctic Ice Blog and on FishOutofWater’s Daily Kos page. At the center of this controversy will likely be the issue of whether or not PAC 2013 enhanced or impeded melt. An issue arising from the new possibility that human warming enables summer storms to melt and thin Arctic sea ice.

This new possibility emerged in the wake of the Great Arctic Cyclone of 2012, which is shown to have melted about 250,000 square kilometers of sea ice, contributing to, but not causing, the record melt seen in that year. 2013’s PAC is likely to prove even more controversial due to the fact that its primary action was to thin and fragment thicker ice during June, rather than blow large holes in already weakened ice during August.

Regardless, the discussion will probably be far-flung. Just one more aspect of our evolving understanding of a rapidly changing Arctic.

Not Quite Done Yet

PAC 2013 is not done quite yet, though. So here’s a basic assessment of its, likely, last days.

As noted above, PAC 2013 is expected to transition to Baffin Bay, then re-develop over the Central Arctic, before retracing its steps through the Canadian Archipelago and, finally, out of the Arctic. It will be very interesting to see what happens to the remaining Baffin Bay sea ice, which has been substantially thinned during the June melt and may now see impacts from this storm.

Here is the ECMWF model run for June 20th showing a 985 mb PAC about the eject itself from the Arctic:

PAC 2013 June 20

(Image source: ECMWF)

It is also worth noting a very strong ‘warm side’ to this PAC persisting over Alaska and the Beaufort Sea. This particular region of warm weather has spawned some very hot temperatures over Alaska and resulted in a broad swath of melt lakes forming over the Beaufort, Chukchi, and East Siberian Seas. This particular warm air pulse has lasted for at least a week and may have consequences for mid-to-late June melt (I’ll be exploring this Alaskan Heatwave more in another blog).

PAC’s transitions over the thickest ice appear to be having impacts, which you can see in the US Navy’s CICE model runs below:

arcticictn_nowcast_anim30dJun18

(Image source: US Navy)

Note the substantial reductions and fragmentation in the large pack of thick ice just north of Greenland and the Canadian Archipelago even as the already fractured ice from Svalbard to the East Siberian Sea continues to thin and break.

It is also worth noting that the CICE/HYCOM model shows substantial impacts you would expect from a PAC continuing on until June 25. Whether this is indicative of a disagreement between US Navy and ECMWF models on the length of PAC duration or just a projection of after-effect is unclear.

To this final point, one caution. Though models now show the absence of PAC 2013 from June 22 on, this particular storm has shown a dogged resilience. Further, even after the ECMWF model shows PAC 2013’s exit, a number of smaller storms are shown to enter and leave the Central Arctic. So it’s not, as yet, a decisive end to stormy conditions there.

Links:

Climate Change Pushing Extreme Events into Higher Gear: PAC 2013 Enters 4th Week, Greenland Melt Hits 27%, US Sees Powerful Storms Spawned by Derecho, and Ongoing Western Drought Spawns 3rd Record Colorado Fire

This past week has hosted a variety of extreme and unprecedented weather events. In the US, storms pummeled a region from the Dakotas to the US East Coast while Colorado suffered its worst wildfire ever recorded, the third time such a dubious record has been broken in the past year. And, in the Arctic, a persistent cyclone (PAC 2013) ended its 3rd week of ice thinning as Greenland melt blew through the usual summer maximum with hardly a pause.

US Derecho, Severe Storms

A storm system that spawned numerous severe thunderstorms, high wind events, hail, heavy rain, and sporadic tornadoes swept through a broad swath of the northern, central, and eastern United States from Tuesday through Thursday. Major power outages were reported over this broad region and, sadly, one death occurred when a little boy lost his life to falling trees in Virginia on Thursday.

This combined derecho and severe thunderstorm event, though less severe than last year’s June 29th ‘Hurricane over Land,’ still resulted in major impacts. According to Jeff Masters, from Weather Underground:

NOAA’s Storm Prediction Center (SPC) logged 376 reports of damaging thunderstorm wind gusts in the 15 hours ending at 11:25 pm EDT Thursday night, and three of these gusts were 74 mph or greater. SPC is now acknowledging that Wednesday’s bow echo that traveled 600 miles from Indiana to New Jersey was a low-end derecho, with over 150 damaging wind reports. The most impressive thunderstorm winds from the derecho occurred in Wabash County, Indiana, where a “macroburst” produced winds of 90 – 100 mph across an area seven miles long and three miles wide, destroying three buildings and causing extensive tree damage. Total damage from the two-day severe weather outbreak over the Midwest and Mid-Atlantic will likely run into the hundreds of millions of dollars.

You can view the progression of yesterday’s derecho in the NOAA/National Weather Service radar sequence here:

derecho_jun12

Western Drought and Colorado Fires

Meanwhile, the western drought, still covering over 44% of the US, spawned the most damaging fire in Colorado history. Again.

The Black Forest Fire has now destroyed nearly 400 homes, killed 2 people, forced nearly 40,000 people to evacuate, and burned over 18,000 acres. Last year, the High Parks Fire and then the Waldo Canyon Fire each successively broke the record, set in 2002 for the most damaging fire in Colorado history. Now, just one year later, the Black Forest Fire has again taken the record.

Three record damaging fires in one year is anything but normal. But, according to climate forecasts, things are going to get much worse for Coloradans. According to this US Department of Agriculture study, under a ‘moderate global warming scenario’ in which Colorado temperatures rise by an additional 1 degree Celsius by 2050, the area burned by forest fires would increase by 2.8 to 6.6 times the current level.

Fuel for the Colorado fires is provided by an embedded drought which has persisted in the region since last spring. Unfortunately, a switch to mild La Nina conditions in the Pacific may indicate that the US drought is set to expand once more.

Droughts are also predicted to grow more severe for the southwestern and central US as global temperatures rise. And this projected increase in drought conditions not only has implications for increasing risk of fire, it also drastically impacts US food productivity.

Farmers already suffering from last year’s drought can still expect to face climate extremes over a large area of the US. And with La Nina increasing risks that drought will re-expand, it appears the beginning of a long era of damage to crops and increased risk of severe fire via the ratcheting effects of climate change is now starting to settle over the US.

Today’s US Drought Monitor tells that tale all too well:

dm_us_w525_h391.png

(Image source: US Drought Monitor)

Persistent Arctic Cyclone Enters 4th Week

Moving northward into colder climes we enter the epicenter of another ongoing tale of climate change tragedy. In this case, a Persistent Arctic Cyclone which has continued to batter and thin the northern polar sea ice has now entered its fourth week.

The storm is now a 985 mb low centered between Svalbard and the North Pole. Two smaller storms are now also incorporated into its larger circulation and are indicated by the two light blue circles on the map:

Persistent Arctic Cyclone Enters 4th Week

Persistent Arctic Cyclone Enters 4th Week

(Image source: DMI)

The storm continues to pull warmer air into the Central Arctic from the south. Now, much of the Arctic Basin is experiencing above freezing temperatures. Yesterday, Barrow Alaska, one of the coldest cities in the Northern Hemisphere, experienced a 65 degree high, about 26 degrees above average for this time of year.

The below weather map shows temperatures above the freezing point of sea water (-1.9 C) covering all but a few isolated locations. In one location on the coast of Siberia and bordering the Arctic Ocean, the temperature has risen to a balmy 27 degrees Celsius or about 81 degrees Fahrenheit.

synNNWWarctisJune14

(Image source: Uni-Koeln)

Forecasts for the storm have tended to trend for it remaining in the Central Arctic at least until late next week. If these forecasts bear out, by next Friday we’ll begin talking about the month-long storm.

With the storm continuing for so long, it is forecast to really begin digging deep into the Arctic sea ice by next week. US Navy models continue to show major thinning in a broad swath from the Laptev Sea to the North Pole and creeping on toward Svalbard. Such projections show continued, dramatic and rapid thinning ramping up all the way through June 21rst. At this point, PAC 2013 begins to look more like the nightmare scenario I discussed in The Warm Storm blog and less like the strong thinning event we’ve witnessed thus far.

The Warm Storm Begins?

The Warm Storm Begins?

(Image source: US Navy)

It is worth stating that we’ve never before witnessed a Persistent Arctic Cyclone thin the ice to any note-worthy extent during June. This particular storm is already unprecedented in its impacts and the fact that it continues and is projected to continue for at least the next ten days should be major cause for concern.

Simply put, the Arctic sea ice is in ongoing and deepening peril. Should these amazing thinning and melt values the Navy is predicting emerge next week, we’ll have to modify our ‘Ice Free Arctic’ prediction (currently at 10% for 2013) accordingly.

Meanwhile, a related warming and melt is now occurring in Greenland, may be set to challenge an extreme record 120 year melt seen just last year.

Greenland Melt Starting to Go Bonkers

Earlier this week, Greenland melt surpassed maximum summer melt values usually seen in mid-to-late July. Today, these melt totals proceeded to spike without hardly a pause.

Average maximum melt area for Greenland usually peaks at around 23% during mid-summer. By Friday, June 14th, about 27% of the Greenland ice sheet experienced melt. You can see this rapid and ongoing spike in Greenland melt in the graphic below:

greenland_melt_area_plotJun14

(Image source: NSIDC)

Current melt coverage is still below last year’s record of near 100%. However, those values didn’t emerge until July and current melt is proceeding at a rapid enough pace to raise concerns that the 2012 record could be challenged this year.

Greenland melt is a major driver of extreme weather events. Melt has currently reached an average of 500 gigatons from the Greenland ice sheet annually. This level is already three times that observed in the 1990s. But melt rates are still rising over time. This massive and growing volume of melt water has already slowed the Gulf Stream and is likely playing a role in severe winters and springs in Europe.

Combined with sea ice erosion, which Dr. Jennifer Francis has implicated in a slowing of the Northern Hemisphere Jet Stream, Greenland melt is a powerful driver of the extreme weather we expect to see as climate continues to change.

Of these four events, three — the Colorado fires, PAC 2013, and amplified Greenland melt — can be directly attributed to a warming climate. The derecho, on the other hand, was likely made worse by a combination of alterations to the global jet stream, increased atmospheric heating, and increased water vapor pumping up the thunderstorms it spawned. Together they provide a context of climate change. One we are just starting to see emerge and one that will likely grow far worse should we not rapidly reduce our use of fossil fuels.

Links:

Hurricane over Land

Weather Underground

National Weather Service

US Department of Agriculture Fire Study

US Drought Monitor

DMI

Uni-Koeln

US Navy

NSIDC

Arctic Ice Graphs

Persistent Arctic Cyclone Strengthens, Greenland Melts, Warm Air Building Around The Arctic

Before we go into a round-up of today’s Arctic sea ice conditions and melt forecasts, it’s important to note a few things. The first is that the Arctic has suffered an amazing loss of sea ice since 1979. An 80% volume loss and a 55% percent area loss over the past 33 years is an ominous event that will continue to impact our climate for years and decades to come. It is also a signal of how little resilience remains to the ice.

The Arctic, as such, bears deep and abiding scars inflicted by human-caused climate change. The sea ice remembers well these scars. Less energy will be needed to melt the ice than was necessary thirty, twenty, or event ten years ago. And the wounds inflicted in 2012 may prevent the Arctic from ever recovering to any state similar to the cold, frozen environment we once knew. Instead, we’ve entered a period of lasting damage and rapid change. A period where an extreme lack of resiliency is visible in nearly all regions of the sea ice pack.

Signs now show a speedy and violent loss of Arctic sea ice integrity — over the entire ice pack.

Re-Strengthening Cyclone

One part of this story is an Arctic Cyclone (Persistent Arctic Cyclone 2013 or PAC 2013) that emerged on May 26th and has continued to plow through the dense ice at the Arctic’s center ever since. At its strongest, the storm showed pressures in the range of 975-980 millibars. Today, the storm deepened to similar levels:

PAC2013June10

(Image source: DMI)

The storm is now centered in the northern Laptev Sea, drifting close to an area thinned by warmer temperatures and early-season sea ice melt. Since the ice in this region is less resilient than the thicker ice of the Central Arctic, we can expect more visible thinning. Physical impacts from the storm — churning, mixing, upwelling and potentially above freezing surface precipitation — are all likely to erode sea ice in areas beneath its circulation.

The US Navy’s CICE/HYCOM model displays strongly enhanced melt and thinning projected for this region over the coming days:

Persistent Arctic Cyclone churns through Laptev on June 9-11

Persistent Arctic Cyclone 2013 is forecast to churn through the Laptev sea ice on June 9-13 before returning to Central Arctic. The above thickness model shows current and projected impacts.

(Image source: US Navy)

Note the large region of melting and thinning ice stretching from a swath directly north of Siberia, through the Laptev Sea and on toward the North Pole. The counter-clockwise motion of the storm is projected to pull the ice apart even as the physical forces of the storm, described above, further thin the ice. In many instances, we see the ice projected to thin to between 1.2 and .8 meters.

Meanwhile, an area directly under the North Pole is projected to break and thin further as PAC 2013 returns to the Central Arctic later in the forecast period.

ECMWF model forecasts show PAC 2013 moving to hover over the Canadian Archipelago by June 18th. The storm is expected to continue until at least June 20th, nearly a month after its entry into the Arctic on about May 26th.

Warm Air Building Around the Arctic

As the Persistent Arctic Cyclone of 2013 continues to rage near the Arctic’s heart, warmer air keeps funneling in around and behind it.  Near Kamchatka, a northward bulge in the jet stream bore a bubble of warmer temperatures up into the Arctic. Over the past day or two, these average above freezing temperatures have spread to cover much of the Beaufort, Chukchi, and East Siberian Seas, a knuckle of this warmer air reaches almost all the way to the North Pole even as the region of below 0 Celsius temperatures stretches and thins.

Arctemp_June10.big

(Image source: DMI)

This large bulge of warmer air also shows areas near the Mackenzie Delta and in the East Siberian Sea with average temperatures above 5 degrees Celsius and areas hugging the coast averaging above 10 degrees Celsius. This is a powerful warming that is likely to impact ice-covered regions.

Models show warmth in the area continuing through at least next week. Barrow Alaska, notably, is predicted to see high temperatures around 65 degrees Fahrenheit by this Thursday.

The see-saw motion of the Persistent Arctic Cyclone has now alternately drawn warm air in from Scandinavia and Kamchatka. It is worth noting that a region of hot air has again developed over North-Eastern Europe. These warmer temperatures, should they persist, are likely to be drawn into the Arctic when/if the Cyclone again shifts to the Canadian side of the Central Arctic.

A more current temperature map shows this warming as a display of hot pinks over North-Eastern Europe, with warmer air even extending into the Kara Sea. A cursory look also shows very few readings below the -2 Celsius freezing point of sea water. Yet one more sign that warmth is building.

TempsaroundtheArcticJune10

(Image source: Uni-Koeln)

 

Greenland Melting

It is also worth noting that the coldest reading on Greenland, now, is -1 Celsius, where warming temperatures there have fueled a burst of early season glacial melt. Melt values have spiked well above what is typical for June and entered territory usually reserved for July — the height of the Greenland melt season.

Melt areas for Greenland spiked to over 20% of the ice sheet surface over the past few days. Maximum melt area averages around 23% during mid July. So Greenland melt this year is already at least a month ahead of schedule and has more than caught up with slower melt experienced during May.

greenland_melt_area_plotJun10

(Image source: NSIDC)

Last year, Geenland set new melt records with melt exceeding any period in at least the past 120 years.

Overall, conditions throughout the Arctic point toward a rapidly progressing melt season. Temperature measures and temperature and weather forecasts over the coming days are likely to continue to push more rapid sea ice melt. Sea ice edge melt and damage due to the ongoing Persistent Arctic Cyclone of 2013 are likely to be the greatest contributors. Large spikes in early season melt to record or near record values are certainly possible given current conditions.

Greenland melt, already proceeding more rapidly than normal, will also bear close watching. It may be possible that melt values will challenge records set in 2012. Should such an event occur, we will have yet more proof that current, very rapid, ongoing, and increasing Greenland melt is well outside the range of ‘normal.”

Links:

US Navy

DMI

Uni-Koeln

NSIDC

 

 

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