Wow, this is a truly extreme solution from NASA GEO5

Wish I could see further on NASA

Ends with an epic cold pool on collision course with the UK!

quite a block in the 06z run - just noticing that it's still average temps for the SW of 8c:

Snow showers or wintry flurries? By Sunday?

More persistent snow for the SE with snow flurries or showers elsewhere?:

Deep in FI THE PV split's does it not?  - OK not the warming but still will this have an additional effect?

Well we have seen it modelled numerous times this winter at the T240+ stage and it has never come close to materialising in the real world, hence my scepticism.

edit: that was in reply to coldwinterfan's post about the retrogression. 

The 06z GFS shows an easterly-like airflow all the way to the 384 hrs range. The only odd day out is tomorrow.

One run, etc, and all that, of course. Just cool (as so to speak) to see.

Cold pool forming in situ over the UK. That's not something you see everyday

Except from June to August every year 

I have said it before, there are some people that could see the negative of a lottery jackpot win.
Scandi blocks notoriously difficult to model, dealing with a reversal of pattern is difficult at the best of times, but the weirdness of this year with still wQBO (which I think has probably scuppered what would have been a classic winter), with the PV being blasted has made it more so.
Get the block in place (which we do) then see what happens. Looking back at the 80's, they were always forecasting the block to be broken down, instead they just meander around. I believe we are seeing the advances in modelling picking up on the meandering.

 

My eyes at this point will now look toward the Meto and media for updates, as we have just seen (Meto 6z) BBC Weather just tweeting cold weekend with snow flurries.

If the 'meandering' pattern holds up and we get some snow cover then the slight amelioration of temperatures in the medium/longer term GFS forecast ………...will largely disappear.

The GFS 06z SLP/500hPa ensemble mean chart for a week ahead (T+168):

Spreads indicate relatively low uncertainty levels as regards the Scandi high - 5 or 6 dam, so close to 560 dam.

M' Dad, used to tell me that in the winter of '47, the forecasts were of snow quickly turning to rain - so……. much the same then as in the eighties and now.

If the 'meandering' pattern holds up and we get some snow cover then the slight amelioration of temperatures in the medium/longer term GFS forecast ………...will largely disappear.

Something similar in 1962-63: repeated predictions of a thaw setting in.

It's something you notice if you follow the charts for the historical cold spells - the synoptics change but always seem to reset into another cold pattern.

But they are exceedingly rare so a repeat is very low probability.

The real cold 850's transfer to eastern Europe next week

Well we have seen it modelled numerous times this winter at the T240+ stage and it has never come close to materialising in the real world, hence my scepticism.

edit: that was in reply to coldwinterfan's post about the retrogression. 

Hi Rob

I know where you're coming from but this time we have by far the best background signals of the winter, with a high amplitude phase 7-8 MJO propagation coupled with the polar vortex stretching and splitting being about as good as it gets (if only the timing was so optimal!).

I have spent some time trying to figure out what's messing with ECM's reading of the signals and whether it could be a genuine phenomenon that should be factored in, but so far have come up with nothing of value.

Anyway - as far as we (professionals in general) know, high latitude blocking is currently more plausible than not for mid-late Feb. That's as far as I can say without getting told off 

Short term ens

The real cold 850's transfer to eastern Europe next week

Ensembles are very split next week, with clustering around mild and cold solutions (in terms of 850s) so the mean is not really representative.