Sudden Strat Warming and Morocco

[Len W]

US to shiver in 'once-in-a-generation' polar vortex

'Forecasters are attributing this cold snap to a sudden warming above the North Pole, caused by a blast of hot air from Morocco last month.'

That is a new on me.

LOL

https://www.bbc.co.uk/news/world-us-canada-47047089

Len

Wembury

[Jack Harrison]

 A new one to Len: 'Forecasters are attributing this cold snap to a sudden warming above the North Pole, caused by a blast of hot air from Morocco last month.'

Pretty obvious I would have thought?  :-) :-)

Jack

[Len]

Personally, I thought it more likely to be from Mauretania.

Where they got Morocco from I don't know.

😀

Len

[Smartie]

You'd have to do a bit more work to get an optimal plot but the attached rough shows 250 hPa height anomaly in the run upto the SSW through late December. The ridge extending from North Africa was associated with isentropic transport into the lower Arctic stratosphere and heating. There was also wave breaking going on dumping heat higher up. I've seen suggestions internal variability played a big role this event as well.

[Stephen Davenport]

Possibly the original source - Dr Judah Cohen:

https://twitter.com/judah47/status/1090377326196674560

Minimum in Indianapolis last night was -24 C, wind chill in the negative 30s. I'm glad that I invested last week in one of those daft furry trapper hats. Colder in the Upper Midwest with minimum air temperatures -35 to -30 C, while parts of Manitoba had -45 to -40 C.

After some snow Thursday night a quick warm-up is coming: Friday's and Saturday's highs will be in positive single digits, double digits for Sunday.


Stephen 
Indianapolis, IN.

[Paul Garvey]

Interesting, TY.