Thursday 30 January 2014

Disasters for coastal and interior Alaska

"if you’re one of those sensitive, perceptive souls who feels that the weather events you’re seeing, the extreme swings from very hot to somewhat cool temperatures, the extreme swings from drought to record rainfall, and the extreme events now accelerating the melting of the world’s ice and snow, are freakish, strange, and terrifyingly abnormal, then you are absolutely correct. Don’t let anyone, be they friends or family, or journalists in the media, tell you otherwise. There is reason for your discomfort and there is very serious cause for concern."
---Robertscribbler

Arctic Heat Wave Sets off Hottest Ever Winter-Time Temperatures, Major Melt, Disasters for Coastal and Interior Alaska


28 January, 2014
Major melt in the midst of winter. Doesn’t sound quite right, does it? We tend to think of winter as the time of freezing, as the time of ice accumulation. Not the time of melt and thaw.
Now try this — major melt in Alaska in the midst of winter. Average temperatures 40 degrees hotter than normal in the midst of winter. Rainfall over snow and ice causing avalanches, major road blockages and ice dams to rivers in the midst of winter.
In this instance we have been transported from the somewhat odd into a reality that is completely outside of our previously ‘normal’ context. In this instance we are transported to a time that may well seem like the beginning of the end of the age of ice on planet Earth.
And yet this is exactly what is happening: one of the coldest regions on the planet is experiencing melt and related record heat in January.
For the state of Alaska, the consequences are a strange and freakish winter heat wave, one that features the extreme temperatures mentioned above. For the city of Valdez, as we shall see below, the situation is far more stark.

(Massive Avalanche set off by rainfall, winter warmth, cutting off Richardson Highway to Valdez Alaska and forming a dangerous ice dam of the ironically named Keystone Canyon’s Lowe River. Image source: Alaska Department of Transportation and Public Facilities.)

Hottest ever Winter-time Temperatures for Alaska
On Sunday, a collapse event that flooded the Arctic with heat and ripped the polar vortex in half began. A freakish high amplitude ridge in the Jet Stream that had been pumping warmth over Alaska and into the Arctic for ten months running strengthened. The result was that many regions throughout the state experienced their hottest temperatures ever recorded for that day, month, or season.
According to reports from Weather Underground, Homer Alaska, for example, experienced an all time record high for the day of 55 degrees Fahrenheit, 4 degrees hotter than the previous all-time high set just a few years earlier. And Homer was just one of the many cities sitting in a broad region of extraordinary, 40 degree hotter than normal temperatures. A region extending from the interior to the southern and western coasts. Bolio Lake Range, about 100 miles south of Fairbanks in central Alaska, saw temperatures rocket to 60 degrees, just 2 degrees short of the all-time record high for any part of the state during January (the previous record high of 62 was set in Petersburg, nearly 700 miles to the south and east).
Typically colder high mountain regions also experienced record warmth for the day. A zone 10,600 feet above Fairbanks hit 32 degrees Fahrenheit on Sunday, the highest temperature ever measured for this region during any winter-time period from November through February.
Even before the most recent extreme Arctic temperature spike, January saw numerous powerful heat influxes for Alaska with Nome, Denali Park, Palmer, Homer, Alyseka, Seward, and Talkeetna each setting all-time record high temperatures during the month.
These records come on the back of a long period of rapidly increasing Alaskan heat stretching all the way back to the 1970s. In many cases, we are seeing all-time record highs broken with 5-10 year frequency. In the most extreme cases, these records fall again after only standing for 1-5 years.
Taken in this context, what we are seeing is the freakish continuation of an ongoing period of inexorable Arctic warming providing yet one more major insult to the Alaskan climate during the winter of 2013-2014.
Rain and Melt Sets off Major, Spring-like, Outflows From Streams and Rivers
The same anomalous Jet Stream pattern that has acted as a conveyer belt continuously transporting heat into the high north over Alaska has brought with it an almost endless series of rain events to coastal Alaska. Storm after storm, fueled by heat and high rates of evaporation over the northern Pacific, slammed into the Alaskan coastline, disgorging record levels of precipitation.
With temperatures freakishly high, mirroring conditions typically present during late spring or early summer, much of this precipitation fell in the form of rain. Valdez, Alaska, for example, has likely experienced its wettest January ever with rainfall measures just 1.35 inches short of the record on Sunday and a series of strong storms rushing into the city on Monday and Tuesday. Given the nearly endless train of storms lining up to sweep over Valdez, it is possible that its previous record of 15.18 inches for January could easily be surpassed by an inch or two at month-end.
The storms and cloudiness make it difficult to peer down and get a good view of what all this heat and rainfall is doing to the Alaskan snow and ice pack. But, for brief respite, on January 25th, just ahead of the most recent influx of rain and warmth, the clouds cleared, revealing the land and sea surface. And what we witness is extraordinary:

(Southern Coast of Alaska with major sediment outflow from snow and ice melt, record heat and rainfall in January 2014. Image source: Lance-Modis)

The entire southern coast of Alaska from Prince William Sound to Cook Inlet are visibly experiencing major snow and ice melt along with flooded streams and rivers flushing out a massive volume of sediment into the Gulf Alaska. Clearly visible in the satellite shot, the sediment now streaming into the ocean is more reminiscent of a major late spring flood event than anything that should be ongoing for Alaska in the midst of winter.
Yet here we are. A situation of continuous, never-before seen heat for Alaska during winter time bringing on a flooding thaw that is far, far too early.
Rainfall over Glaciers, Snow Pack Triggers Massive Avalanche that Cuts off Valdez
The constant assault of heat and record temperatures combined with an almost endless flow of moisture riding up from the Gulf of Alaska set off a devastating and freakish event near Valdez on Saturday. Severe and record rainfall over the mountain regions have continuously softened glacial ice and snow packs above this major Alaskan city. On Monday, the continuous insults of heat and water passed a critical threshold.
As the warm water filtered down through the colder snow and ice, the anchoring base was lubricated even as the capping snow grew heavily burdened with water. Eventually, the insults of heat and rainfall became too great and a major snow and ice slope system above the main road linking Valdez to mainland Alaska collapsed. The immense volume of snow and ice unleashed, spilling down to fill the base of Keystone Canyon, blocking both the Lowe River and the Richardson Highway running through it.
This snow and ice dam rose as high as 100 feet above the Canyon floor, causing the Lowe River to rapidly flood, inundating the already snow-and ice buried road under an expanding pool 20 to 25 feet deep and filled with ice-choked water.
You can see the massive avalanche-created ice dam and related road inundation in the video provided by akiwiguy below:



(video source: akiwiguy)
Warming-related rainfall events of the kind that has now cut Valdez off from the mainland are just one of the extraordinarily dangerous consequences of human-caused climate change. They are a phenomena linked to the massive glacial outburst flood that killed thousands in India this year together with other dangerous snow and ice melt events. Should such major heating and rainfall events impact Greenland and West Antarctica, the consequences could be even more extreme than what we are currently witnessing in Alaska.
Conditions in Context
In the context of our present extreme Jet Stream pattern that is setting off warmest-ever conditions for Alaska during January together with dangerous melt-outburst related events while at the same time periodically flushing Arctic air and extreme winter weather south into the United States, it is important to remember a few things. The first is that the Arctic is now experiencing never-before observed warmth with stunning frequency. Scientific papers now show that the Arctic is hotter than it has been for at least 44,000 years and possibly 120,00 years.
By comparison, the cold snaps, that could very well be seen as the death gasps of the Arctic we know, impacting the eastern US are relatively minor when put into this larger, more ominous context. Similar cold events were last seen about 20 years ago in the US. And so there is simply no comparison that can generate a rational equivalency between the, hottest in an age, Arctic temperatures and the, coldest in a few handfuls of years, temperatures in the Eastern US.
And if you’re one of those sensitive, perceptive souls who feels that the weather events you’re seeing, the extreme swings from very hot to somewhat cool temperatures, the extreme swings from drought to record rainfall, and the extreme events now accelerating the melting of the world’s ice and snow, are freakish, strange, and terrifyingly abnormal, then you are absolutely correct. Don’t let anyone, be they friends or family, or journalists in the media, tell you otherwise. There is reason for your discomfort and there is very serious cause for concern.
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