In the wake of a record warm September, a strongly negative Arctic Oscillation (AO) with persistent blocking high pressure over Scandinavia which has made for a cold October.
Credit: Michael Ventrice
-AO forced by a nice tropospheric warming event.
October temperature anomaly so far this October.
Credit: Michael Ventrice
It’s been a record warm October over the Eastern United States.
Credit: Michael Ventrice
Note below the strongly negative AO but positive NAO (North Atlantic Oscillation)
However, there’s good model consistency and agreement that the NAO is set to join the AO and go negative.
A cold open to November?
GFS 50mb temperature forecast supports warming and high pressure over Greenland and Arctic.
00 hours
120 hours
168 hours
CFSv2 weeklies say yes to Greenland blocking showing up reflective and mirroring the warming higher within the atmosphere!
Credit: Tropical Tidbits
Credit: Tropical Tidbits
Credit: Tropical Tidbits
Credit: Tropical Tidbits
Credit: Tropical Tidbits
The above 500mb height anomaly through the next 4 weeks suggests at least a cold open to November but CFSv2 weeklies show a warming trend in the means towards mid November.
Credit: Tropical Tidbits
Credit: Tropical Tidbits
Credit: Tropical Tidbits
Credit: Tropical Tidbits
Credit: Tropical Tidbits
GFS ensemble also on board.
Credit: Tropical Tidbits
Credit: Tropical Tidbits
Credit: Tropical Tidbits
November Overview
Going by all the evidence I have available up till now, I expect to see a colder-than-normal first half to November with snow mainly confined to higher ground over the UK but we could see surprise low level snow based on the above. Nights could turn unseasonably cold for the time of year. The majority of the continent will be cold with snowfall even to lower elevations of Germany, Poland etc.
I expect a pull back and moderation during the second half of November with more Atlantic influence returning as AO/NAO is likely to go positive.
CFSv2 for November overall.
Credit: Tropical Tidbits
Credit: Tropical Tidbits
FOR MORE ON THE UPCOMING WINTER: LOW SEA ICE, WEAK VORTEX, RAPID EURASIA SNOW GROWTH MAY FAVOUR COLDER WINTER
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