The new run of the ECMWF has come out and I really wanted to wait till this came out before posting on next week. Firstly, it’s worth pointing out that while an Iberian high tries to pump warmth into the UK this weekend and likely will produce 14, maybe 15C by Sunday along with heavy, flooding rains, models have been persistent on that ridge sliding east between Sunday and Tuesday-Wednesday. In doing so, this will force heights to lower over the UK and Western Europe with colder air dropping south, meanwhile rising further east. This setup break the Moscow and Eastern Europe freeze.

I also want to make sure your looking outside the box when it comes to cold and this winter, that’s why I post on Asia and not just for cold weather stories. There is a point in drawing your attention to what’s going on GLOBALLY. Most weather websites will look only local, while I’ll show you global and what it means to us.

Indeed many of you dear folks are American so I try to balance my forecasting schedule between yourselves and us here in the UK.

Interesting times for sure over the US as models are firmly locking a colder pattern in, especially in the 8-16 day after a balmy start to December.

[s2If current_user_can(access_s2member_level1)]

The fierce cold that has plagued a large swath of Asia this month will ease considerably and that process has already begun with temperatures now somewhat ‘recovering’ in the Kazakhstan capital of Astana. It’s while the cold eases in Asia, it’s snowpack building time in the Lower 48, which could allow the coldest air mass on earth to focus on North America between Dec 25 and Jan 15. This game changer may support a return to colder times here in the UK but given the position of the blocking high, while favourable for the US, especially with the PNA now starting to go positive, finally, this doesn’t support a LOCKDOWN cold pattern here, but it may mean more frequent blasts of colder weather.

The blocking high is centered between Hudson Bay and Greenland, very favourable for the United States like I say but because it is further west, the UK is open to variability and a likely up and down pattern. Without a block further east and centred more over the North Atlantic, so there is a chance of a more westerly, perhaps southwesterly flow. However, if we get a lot of cold building over the North Atlantic and the jet rides further south, then whether it’s zonal or not, we can still have codler than normal weather, albeit more unsettled.

Recent model output, including the very latest ECMWF does show a zonal flow but with low heights at our latitude.

Check out the 500mb upper pattern for tomorrow – Saturday.

Note the positive heights (block) spread out across the top but the Iberian high poking it’s warmth up into the UK. This ridge continues to feed in cold, Siberian air into Moscow and the Southeast corner of Europe. Note the trough and lower thicknesses WEST of the UK.

Now look what happens by Tuesday (Christmas Day).

What an alteration in just 3 days. Gone is the linking high over top of NA and Europe. See how the positive heights consolidate over Hudson Bay, meanwhile the Iberian high slides east and so heights tank over the UK, this should release cold air south, making for a chilly Christmas Day. Snap goes the cold in Moscow and the east as heights rise.

With the block centered more over North America, we have a more fluid upper flow but I believe that lower heights with no Azores high around, we have a stormy but colder pattern evolving, starting at Christmas which may take us through the first week of January

Below is the 29th, note the block holding over NE Canada while we have little high latitude block to our north to keep any cold or warmth locked in place. The flow appears very much zonal for the UK but despite that, with stronger heights to our east and the strongest positive well to our west, there is a tendency for lower heights and colder air over the UK. For folks in Moscow and adjacent areas, modest ridging favours more seasonal cold if not above normal temperatures.

Also, with a westerly flow and a southerly tracking jet, any storms which form should be more to our south than north and anything which crosses our path, should drag down colder air which could present snow oppertunities. Yes, we may also see mild interludes but given what I am seeing, our pattern appears to favour more cold and warm over the next 10-20 days.

[/s2If][s2If current_user_is(s2member_level0)]

Join a subscription plan, [s2Get constant=”S2MEMBER_CURRENT_USER_DISPLAY_NAME” /]!

[warning]You do not have a valid subscription to access premium content exclusive to members. You will need to join a subscription plan if you would like to continue.[/warning][/s2If][s2If !is_user_logged_in()]

Sign in to read the full forecast…

Not yet a member? Start your 7 day free trial

Create your free markvoganweather.com account today to get unlimited access to Mark Vogan’s premium articles, video forecasts and expert analysis for 7 days.
[/s2If]