Last winter was of course cold and snowy for most of the Lower 48. The thing is, it was predominantly fuelled by a warm NE Pacific but based on additional cold signals and recent ‘cold trend’ of the last 12 months or so, I ask the question, could we see a ‘super’ cold outbreak this winter? A severity of cold not seen since 1994?
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I display my reasons of concern.
Last winter was up against a west QBO, neutral ENSO and solar max yet it was the coldest since 1996.
As for this winter, well the cold pattern with AK blocking and semi-permanent troughs over the eastern US is well established.
Signals which favour US cold and are now in place…
1) Continued warmth in NE Pacific
2) Warming of the central Pacific (El Nino)
3) Downturn in solar cycle 24
4) Easterly QBO
5) North Atlantic tripole (favours more Greenland blocking)
6) Near record Siberia snow cover in October
7) Arctic sea ice is up on recent years
8) -AO trend into winter
9) Stratospheric warming
As you can see, there’s many more factors in place this year compared to last which support not just another cold US winter but an increased chance of extreme cold.
The continued strat warming could be a harbringer of something bigger. A suddern stratospheric warming like we saw a couple of years ago is one thing but combined with all of the above, well that’s what sparked the super outbreaks of the past.
Here was the result of the SSW back in 1985.
These were the temps as a consequence.
2009 example
It’s dangerous when throwing up years such as 1979, 1980-81, 1985, 1989, 1994, 1996 which produced SUPER outbreaks of cold when all-time records fell. These years are in a league of their own. Most or all occurred following SSW.
The current solar cycle position looks like this. As you can see, most of the above years occurred during or near solar minimums.
However the closest extreme event with a resemblance to the current solar state appears to be 1989.
Current SSTA’s are strikingly similar to those back at this time in 2009. The 2009-10 winter was cold with abundant snow in the east. Arguably the current anomaly and position of the warm and cold pools are more conducive for cold this winter compared to 2009 with warmth in the NE Pacific.
Current
2009
There’s continued warming of the stratosphere between Asia and North America which is arguably responsible for last winter’s cold and this autumn’s to date. If and it’s a big if, that we see another SSW once we get into the winter, I recon we could have another super outbreak in late December, January or February based on all the other above factors. Whether is threatens some of those big records, well that would be an achievement.
Up till now the AO has been negative with two big dips which produced historic cold in October and especially November.
It’s flipped positive in the past week but as you can see, it’s set to go back negative.
Here’s the eastern US/Western Europe analog when the mean winter AO is at or below -1.5.
Keep in mind that this is more theory than forecast.
See the video just uploaded for the discussion.
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