Unusually Warm Early Arctic Spring Predicted Following Second Lowest Sea Ice Maximum on Record

After a brief Arctic cool-down late during a much warmer than usual freeze season, sea ice extents tortuously rose out of record low daily ranges during mid-March. This feeble climb was enough to barely hit above 2017’s record low maximum extent. It did not, however, push the Arctic out of its present trend of long term declines. Moreover, we are again set on a very low platform for sea ice as we enter what is predicted to be a warmer than normal start to melt season.

(Arctic sea ice losses are a long term trend that has been in place since the early to mid 20th Century. The recent satellite record captures this ongoing loss due to polar warming and triggered primarily by fossil fuel burning. In keeping with this trend, 2018 saw the second lowest sea ice extent maximum on record. Image source: Zack Labe. Data Source: JAXA.)

Arctic sea ice extent measured by JAXA and depicted above by Arctic observer Zack Labe, hit 13.89 million square kilometers on March 17th. Given the fact that warmer Arctic temperatures are now on the way, this is likely the furthest sea ice will extend in the northern polar region during 2018. By comparison, 2017 sea ice extent maxed out at 13.88 million square kilometers on March 6th of that year. As a result, 2017 just barely beat out 2018 as the lowest maximum extent in the satellite record according to JAXA.

A brief spate of cooler than average temperatures contributed to a short period of expanding sea ice late during freeze season. This cool snap in a much warmer than normal winter overall, has now ended. And the forecast shows that warmer to much warmer weather for late March may well be on tap.

Over the next week and a half, Arctic temperatures are expected to range between 0.2 to 0.8 C above average. This may not sound like much compared to the past winter which experienced long periods of 3-5 C above normal temperatures. However, the transition to spring and summer typically shows a regression toward baseline averages. In other words, since winter is where we are seeing most of the climate change related warming at present, even slightly warmer than normal temperatures during spring and summer can have an outsized impact. Especially following a very warm winter like the one we have just seen.

(The ten day forecast is presently predicting a very substantial Arctic warm-up. If this forecast is correct, it could result in a fast start to melt season. With sea ice extents already near record low levels, this potential is rather concerning. Image source: Climate Reanalyzer.)

Keeping this thought in mind, we are more likely to see slowly mounting sea ice losses over the coming days in various regions. Especially on the Pacific side of the Arctic — which is presently seeing above freezing temperatures running up through the Bering and well into the Chukchi seas. Given such a strong warm wind invasion over a key region of ice, we are very unlikely to see sea ice expansion beyond the present maximum.

Looking at the long term forecast, we find that the Arctic is expected to experience substantial warming — especially for spring. And this warming may serve to accelerate melt beyond typical rates for this time of year. The tendency for Pacific emerging warm winds appears to be in place. And by April 1st, a large plume of abnormal warmth is expected to run up from the Pacific and Eastern Siberian side of the Arctic. This plume is forecast to spread deep into the High Arctic — driving overall temperatures for the zone to 4.1 C above average with local temperatures between 20 and 25 C above average. If the present forecast holds, this unseasonal flow will also result in large regions of the East Siberian Sea experiencing above freezing temperatures for brief periods.

Taken in the greater context, if the predicted warm pattern of the next ten days becomes more of a trend for spring of 2018, then the near record low maximum of 2018 could well be followed by significant losses during melt season. Definitely a trend to keep an eye on.

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