Polar Vortex Ripped in Half by Anomalous Jet Stream, High Arctic Experiencing 32 Degree F Above Average Temperatures Over Broad Region
A dangerous and weather-wrecking polar heat amplification in the Arctic set off by human-caused global warming keeps kicking into higher and higher gear…
27 January, 2014
What models predicted earlier this week and what we reported on Thursday has finally happened. A major influx of record-breaking winter warmth has flooded into the high Arctic, disrupting the polar vortex to the point that it is currently ripped in twain.
Average temperatures over a broad area of the north polar region are now in excess of 20 degrees Celsius (32 degrees Fahrenheit) above daily norms for this time of year. Areas from Alaska to Norway to Greenland to the North Pole are experiencing record or near record highs. Meanwhile, the circumpolar Jet Stream has been malformed into an extraordinarily exaggerated north-south Rossby Wave pattern. An extreme amplification of a blocking pattern that has been in place for more than 10 months, pumping a continual flow of heat into the Arctic, and which, this winter, has resulted in numerous North American cold snaps comparable to those that used to happen in the 1980s and 1990s.
(Global temperature anomaly vs the 1985 to 1996 mean. Note the large regions of the High Arctic experiencing temperatures that are 20 degrees C above average or higher. Image source: NOAA)
The result is a kind of north-south flip-flop in temperatures following a polar vortex that has been ripped in half by a surge of anomalous warmth and a periodic pulsing of the Arctic’s remnant cold southward over the continents.
Yesterday, the high temperature in Svalbard, for example, less than 600 miles from the North Pole peaked at 32 degrees Fahrenheit, near all-time record warmth for this frigid region. In contrast, the high for Bethesda Maryland, thousands of miles to the south, was nine degrees lower at 23 Fahrenheit.
Hottest or near hottest ever temperatures in the Arctic are, in this case, comparable to moderately colder than average weather over Siberia and the Eastern US (As seen in the NOAA temperature anomaly map above. It is also worth noting that the 1985-1996 base-line temperature for the above map is already about .5 C above the 1880 average. So this map doesn’t take into account the full extent and impact of human-caused warming.).
The Jet Stream anomaly that linked a very large and powerful flood of warm air from the Pacific with another less powerful warm air invasion riding up over Western Europe setting off such major polar temperature extremes is now plainly visible in the University of Washington upper air flow graphic below:
(Polar vortex ripped in half. Image source: University of Washington.)
On the Pacific side, we see a powerful ridge in the Jet Stream invading deep into the Chukchi and Beaufort Seas before again turning south. Some of the warmer air carried up by this extreme northward thrust of the Jet, however, bleeds further north, spilling up and over the North Pole. There it links with the second warm air thrust coming up from Europe. To the south, the polar vortex is now misaligned and severed. The two resulting, lesser, cold vortexes are now centered hundreds of miles to the south of their typical zones — with one over Hudson Bay and the other over the Yedoma region of Siberia.
Over the next week, model forecasts predict this severing of the polar vortex to continue with the current, anomalous, pattern remaining in play at least until February 2nd.
What we are observing is the start of the tumultuous and stormy throws of an imperiled winter in the Northern Hemisphere. A crisis that is bound to continue and worsen for at least some time. One that, if we don’t stop our greenhouse gas emissions soon, will certainly progress to a period in our not too distant future when winter no longer exists, perhaps a century or two from now. But make no mistake, these episodes of extreme polar warmth during wintertime that flush the cold air out and southward are no less than the palpitating heart of winter thrumming with the terrible arrhythmia of its eventual demise.