Winter Approaching: Forecast and Model Discussion Commentary

[WYorksWeather]

 Mike Poole I think it will be an outlier, but probably not completely on its own. This is a seriously cold run now with the -12C down to the Midlands in places.

[LRD]

December 1981 (sort of). Bring it on

[WYorksWeather]

 LRD The Northern Hemisphere profile looks insane. Like an axe head!

[Scandinavian High.]

 WYorksWeather imagine if an easterly sets up with that cold sitting to the east.

[LRD]

 WYorksWeather Indeed! A very strange but very interesting run from the GFS

It doesn't look very secure but if we get those sort of uppers, with some wide snow cover and then the high topples over us there would be some seriously cold nights to be had

[That ECM]

Gfs is fun. ECM would not go that way so plenty more runs needed.

[WYorksWeather]

 Scandinavian High. Yep, this run would certainly solve our 'lack of a mainland Europe cold pool' problem:

In all seriousness I think the odds of this run verifying are about 1% given how extreme it is, but still amazing to look at nonetheless.

[Mcconnor8]

 WYorksWeather That sort of chart is how I imagine some of the epic cold spells in Europe from a long time ago looking, I.e the 1739-40 Winter which was supposedly a huge Atlantic block for 2-3 months on end but probably with colder uppers than shown here. No reanalysis charts go that far back though. Obviously a very low chance of verifying but yes fun to look at.

[LRD]

Collapses in deep FI but there still looks like a nice little gap into Scandi for the high to migrate to

Won't make it on this run but this far out it's nowt to worry about nor get excited about

[Murray991]

 

A North Sea blizzard in FI, JFF

[phil nw.]

A pub run of the finest order straight off the top shelf and wouldn't we all like it to verify.

Not really in line with ens. guidance though.

Edited November 30, 2024 by phil nw.

[damianslaw]

In the near term, we have a rather cold 48 hrs in the north Mon eve to Wed eve, widely temps struggling much above 3-4 degrees, a sub zero mins, wintry precipitation to modest levels as well. 

[Don]

 Murray991 that low in the North sea needs to be a little further west!

[LRD]

Yep GFS finds a way to not have the high topple over us and, instead, have a weird slither of mild air to melt the snow that might have fallen in the previous 3 or 4 days

If you liked warm winter weather you couldn't draw a better conclusion to a potent spell of cold. A load of computer-generated nonsense but entertaining anyway!

[blizzard81]

The most significant development over the last couple of days is not so much how much amplification we achieve in the atlantic. It's more to do with the troughing over southern Europe. This is prevalent now across the suites. It's crucial as it gives us a very good chance at retrogression in mid December. 

[swfc-ocs]

 LRD indeed.plus side know raging sw winds and rain past the coming 7 days be it fi ? Also on the gfs 18z there isn't a lot of action exiting the esb in regard to the pv.

Edited November 30, 2024 by swfc

[Mcconnor8]

 blizzard81 No warnings from @Kasim Awan of the dreaded Euro Heights which plagued us last Winter and many others recently!

[swfc-ocs]

Control on the 18z isn't bad either in fi

[Metwatch]

A polar low slamming into the Netherlands and Belgium on the 18z. Pub run rarely disappoints!

[damianslaw]

I mentioned the atlantic SST profile possibly not being factored into the equation, might this be a factor in reducing the zonal flow at a time it should in theory be on turbo charge given the depth of cold over east USA seaboard, the very strong flow in the strat, unfavourable MJO etc, yet we are seeing a super strong mid atlantic high forecast.. all has a feel of not normal service.. making a mockery of the teleconnections. 

Edited November 30, 2024 by damianslaw

[Mcconnor8]

 damianslaw If the models are signalling this much blocking with unfavourable teleconnections then what could we be in store for when they turn in our favour?

[blizzard81]

 swfc More realistic 

[damianslaw]

 Mcconnor8 Who knows, last winter the teleconnections pointed to lots of cold weather, but alas things didn't play ball. May be a winter that has everyone scratching their heads, cold occuring when all points to mild. The persistant high we had tail end of Oct that hung around for an age caught many out and should have people thinking mmmm.... 

[swfc-ocs]

 damianslaw Id agree tbh.Maybe the big so called players in forecasting with the teleconnections and background signals dont include the more minor increments ie sst /tripole indications

[blizzard81]

 damianslaw Possible. The atlantic sst's are always utmost in my mind at this time of year. Looking for the tripole which looks to be on. All very complex but I think the sst's are not given enough respect.