For many of us hoping for a pattern change to colder, well we’ll need to remain patient as the AO remains strongly positive but is expected to drop towards weak negative in the next week or so.

However, the NAO doesn’t show any real sign of getting much below neutral over the next few weeks and that means the Atlantic continues to rule.

A large reason for no sign of an NAO flip has a lot to do with the strength and positioning of the polar circulation which remains tight over the pole. If a weakening or shift WHICH IS EXPECTED, doesn’t necessarily mean blocking and cold for us.

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The warming of the stratosphere and consequent energy transfer into the troposphere should support building heights into Alaska in early January, this is expected to drop heights over eastern Canada and the US and therefore a colder pattern should kick in.

The reason for no hints of colder times here just yet is down to where the strat warming and vortex displacement is occurring. Like we’ve seen for the past 2 winters, any warming we have seen has been from Asia to North America. A stacked cold stratosphere leaning towards Europe supports negative not positive heights and this also certainly supports a stronger Icelandic trough and continuation of an Atlantic flow into Europe.

Even the AO may have a tough time getting truly negative.

50mb temps for 7 and 10 days.

I’m not sure but I do believe there’s a relationship between El Nino and strength of the polar vortex.

The North Atlantic is opposite of 1997-98 but the overall pattern up till now is very similar.

The reason may be down to too much warmth stacked up against the South America and this is overwhelming the pattern.

In saying that, there’s clear evidence of cooling within Nino 1.2 and if this is a player in the warmth, strength of vortex and lack of blocking, the next question is, is any cooling and westward transfer of warmth into the central Pacific too little too late?

It’s quite possible that the vortex won’t truly weaken this winter based on the strength of the El Nino and even if it does, as already stated, it may be be supportive for Europe cold.

Latest CFSv2 for January now sees building heights into northwest Canada but a negative northwest of the UK which almost certainly holds the current pattern.

Even February shows a Greenland trough with ridging either side.

Canadian likewise has a negative over Iceland but continues to show more blocking in February.

No, I’m not writing off winter but merely showing all sides and all possibilities on the table.

See video for the discussion.

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