This week is undoubtedly the busiest of winter when combining the historic snowstorm potential on the US East Coast and heavy snow expected on this side also. Yes, the Eastern US storm will in-part be responsible for the late week UK cold and snow. There’s a ripple effect and nice teleconnection this week.

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The major deepening bringing the big storm from DC to Boston will effectively reamplify the upper hemispheric pattern. Like a seesaw, as the trough deepens on one side of the Atlantic, the ridge gets pulled west and side there’s strong amplification. That high expands north into Greenland. In response we see a deep trough formation over Europe and with low pressure sliding east and holding over Scandinavia, we find ourselves beneath a cold northerly flow to end this workweek.

The ECMWF 500mb height anomaly charts show this well.

However, while we battle the coldest winds of winter, embedded energy pulses riding the northerly flow will bring potential significant snowfall to parts of Northern Ireland and particularly Scotland along with N England and Wales. Secondary ‘open’ lows, seen on the surface maps as ‘kinks’ riding around the primary (main) low dive south over the UK and it’s these waves which will bring spells of snow, some heavy and this is likely to cause travel issues particularly Wed-Thu. Be sure to check out both ‘Europe videos’ this morning to see more detail.

Here’s the latest GFS surface charts which show the evolution of the return to winter. Notice the ‘kinks’ in the isobar field and notice as they drop south within the flow that they become closed with pressure down to 972.

GFS snow growth through the next 120 hrs (Saturday)

ECMWF

I’ve made mention about that wind feeling cold. When you’ve a strong wind blowing straight out of the arctic, you expect it to feel cold right. Now IF we have a firm snow cover by the time we get to late Thursday/Friday which I think we will, that northerly gale sure will feel colder, given it’s blowing over snow. This will certainly be the ‘coldest feeling’ part of the winter and between pulses, under clear sky and lighter wind, expect the -10 nights to come back.

See BOTH Europe videos in the video section…

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