Tuesday, 2 May 2017

High temeratures in Greenland to precipitate melt

Early Greenland Melt Spike Possible as Forecast Calls for Temperatures of up to 50 F Above Average

1 May, 2017
Greenland — a region vulnerable to the slings and arrows of human-forced climate change — appears set to experience both considerable warming and a significant melt spike this week.
Starting on Wednesday, May 3, a sprawling dome of high pressure is expected to begin to extend westward from the far North Atlantic and out over Iceland. As the high pressure dome builds to 1040 mb over the next couple of days, its clockwise flow will thrust abnormally warm and moist air northward out of the Atlantic. This air-mass is expected first to over-ride eastern Greenland, then run up into Baffin Bay, finally encompassing most of the island and its vast, receding glaciers.
(May 5, 2017 GFS model run as shown by Earth Nullschool is predicted to produce widespread above-freezing temperatures over the surface of the Greenland Ice Sheet. Such warming is expected to be accompanied by rainfall over a number of glaciers. Image source:Earth Nullschool.)

Liquid precipitation is then expected to start falling over southern sections of the Greenland Ice Sheet as temperatures rise to 1-6 C (33 to 43 F) or warmer. Since water contains more latent heat energy than air, such rainfall is likely to produce more melt than would otherwise be caused by a simple temperature rise.

For those of us living in more southerly climes, a temperature of 6 C (43 F) may not sound very warm. But for the northeastern region of Greenland shared by the ZachariaeBrittania, Freja, and Violin Glaciers, such temperatures far exceed ordinary expectations for early May. They are anything but normal. In fact, the building influx of heat is more reminiscent to readings Greenland would have tended to experience during summer — if at all — under past climate averages.

(GFS model predictions for May 4 show widespread liquid precipitation falling over southern Greenland. Image source: Climate Reanalyzer.)

Unfortunately, the new climate presented by human-forced warming is now capable of producing some rather extraordinary temperature extremes. And the anomaly ranges that are predicted for the coming week are nothing short of outlandish.
According to climate reanalysis data, by May 5th, temperatures over northern and eastern Greenland are expected to range between 15 C above average over a wide region and between 20 and 28 C above average in the northeast. For the Fahrenheit-minded, that’s 27 to 50 degrees F above normal. Or the equivalent of a 102 F to 125 F May day high in Gaithersburg, MD.

(An amazing temperature spike is expected to ride up and over Greenland on May 3 to May 5. This warming is expected to produce very extreme above average temperatures for this time of year. Image source: Global and Regional Climate Anomalies.)

Overall excessions for Greenland temperature are also predicted to be quite extraordinary for the day — hitting nearly 9 degrees Celsius (16 F) above average for the whole of this large island. So much warmth extending so far inland and combining with liquid precipitation, if it emerges as predicted in these GFS climate models, is likely to produce a significant early season melt spike — especially over southern and eastern Greenland. In places, these temperatures exceed expected normal summer conditions for Greenland’s glaciers. So it is difficult to imagine a situation where a significant surface melt spike does not occur if these predicted temperatures emerge.

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