One thing I've noticed in the runs that is very consistent, is for an extremely cold siberian high to develop and a classic 'cold continents, warm arctic pattern'

There is some ridiculously cold air Finland eastward that, were a scandi high to setup (and it could) would push the deepest cold this winter in our direction.

Q as much as I admire your enthusiasm I think the ship has sailed now for anything the right side of decent.

I wouldn’t rule out a cool/cold spell before the end of March - no one should - but this winter is almost over for me (not that it really begun here).

.... Careful 

🤫🤫

The 12Z charts don't represent the full potential of what could happen if the high develops slightly further NW. In the 12Z GFS and GFSP the real cold air is cutoff in western siberia, and we end up with a run of the mill scandi flow.

GEM shows the cold air getting into Europe.

So if a scandi high developed at this point it woudl end up being alot colder than the GFS scenario.

CFS shows the other extreme where the high forms too far NW.

Cold gets rerouted via the arctic ocean.

Its a cold northerly but the best route for Siberian cold is a direct one.

GFS Para also has a significant easterly early March.

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=336&mode=0&runpara=1

In the very next run you can see the potential effectiveness of my ruse?

😉😂

This pertubation illustrates the correct positioning of the siberian high.

So the air here is sourced from Russia, not just scandi. This is what we are aiming for.

This one may look similar but is a much less ideal scenario.

Scandi sourced rather than siberian.

There is very good agreement for this siberian high setting up. And its positioning is favourable, i.e in the arctic ocean where the warm air is. 2nd chart shows the uncertainty, which is low in this region.

GEFS continues to show the possibility of it turning colder at the very end and the snow row climbs to 9 on this update.

PS: GFSv16 is scheduled to go live on March 17th.  

Yes - here we go...that SSW is showing it’s hand in the models, and 2018 demonstrated well how March can deliver something memorable, even in these warmed times. Just need the jet amplification to rinse and repeat, which is likely. Anyone for a ride on Stealth? Might be rough but it will have some thrills and spills!!

Jetstream strong across the Atlantic, dipping S before returning to the UK before resuming a more direct route to the UK Mon 22nd. The dip to the S repeats in that week, but there's a chaotic break up after Sat 27th with bits of jet anywhere and everywhere, mostly N of the UK, before regular service is resumed Sat 6th.

GFS shows LP in usual N Atlantic position with first SW-lies then W-lies for the UK until Sat 27th when a small LP runs SE and intensifies over France Mon 1st ushering in a large block of HP Ireland-Baltic Wed 3rd, briefly an E-ly regime but the HP slips back to the SW (end of run doesn't resemble yesterday's forecast at all!)

GEFS very mild to Thu 25th (less so in N) then and mostly continuing to decline to around seasonal norm through to Sat 6th but with wide spread of possibilities, only 2 or 3 runs suggesting significant cooling. Rather dry in E, less so in W esp NW later on (contradicts synoptics).

ECM like GFS but the HP establishes more locally over the UK rather than forming an elongated ridge

What?

It looks likely that London will hit 13'c or higher every day for a week from Saturday with 16'c possible

Pattern still consistent. Siberian high with big area of cold air expected to develop.

However the HP builds slightly further west now

Makes a northerly more likely than an easterly.

Notice how the ensembles that do churn out cold runs in FI are going in full whack. -13C on the T850s shouldn't be that common. There is some serious cold air to tap into if we do indeed tap into it.

The 6Z has it very close indeed

GFS6z is another sinker.