Hello
Haven't posted in a while given the model output had been fairly repetitive. However the 06z offers a route to colder weather. An interesting run that could have a lot of potential with a few tweaks.
So the thing that has been notable with recent output is the development of a very strong area of high pressure around western Canada. Some recent output has seen some quite remarkable SLP values, with yesterdays 06z seeing SLP values of ~1070mb across NW Canada!
I don't think the high will get that strong but it does look like being quite a powerful anticyclone.
We see its development quite early on after T+96. Here is the view at T+114:
Again situated over NW Canada with a cold plunge over Central and eastern North America looking likely. This may fire up the jet, though a split in the Polar Vortex is still possible if the Russian/Arctic high links up with it.
This is shown quite clearly at T144, so the North America high increases even further in its influence.
Interestingly the ECM and UKMO offer some support for this. This high starts to have a knock on effect around Greenland.
At T174 high pressure starts building around Greenland. Given the cold polar air isn't shifted this becomes a very intense cold based high. The ECM and UKMO are not as bullish on Greenland height rises but in recent weeks I've noticed the GFS has done quite well with it. Transient northerlies have been a persistent theme of this winter so far. So the GFS may be onto something.
The development of this high helps split the polar vortex. It is now shunted away from the south of Greenland somewhat and is split to our North and over NE North America. This shunts low pressure systems further south.
Cold air starts building to the North but the Greenland high isn't strong enough to keep the cold air moving south over the UK persistently.
Though this may change. It could be very easy for the warm air being pumped up into the arctic by the North American high to reach Greenland and therefore helping develop a more stable block. Also the GFS after T240 tends to flatten a pattern anyway.
In the end our potential to avoid a euroslug high would be increased if the link up between the arctic high and American high occur with ridging over Greenland.
It may not happen but its worth watching. Also some stormy weather on boxing day seems to be a recurring theme…