SMU

Watch the GEM - it’s even better for undercut @180 the T2M is 0c over the UK..

Text book Easterly @180 on GFS - cold pool developing over the UK in situ atlantic trying to undercut ...

Perhaps a lot of Confusion here - The broad scale pattern is almost identical on all 3 models - 144 long fetch Easterly UKMO fetch is about 90/95 degrees East GEM is about 80 degrees ENE thats the difference between -8c in the SE or 0c ....

Early doors scores GEM 10:10 GFS. 8.5:10 UKMO 7.5:10

Look at the angle of CAA NE of acotland @96 V 06z superb !! cold is going to bomb SW - wait for 114-120

Early doors IKON now following suit - flow direct Easterly -

It’s not a lee flow UKMO + ECM mean 144-168 indicates otherwise - A lee flow has no high pressure support.

I think that statement is banned from this thread lol.

Yep same as PTB 1 ^^^ best UKMO in a long while there is only 1 bite needed-

Last one from me - no 168 UKMO Try PTB 1 - identical to UKMO to 144 https://www.meteociel.fr/modeles/gefs_cartes.php?ech=0&code=1&mode=0&carte= *** watch out for a big dip in mean @192 to sub -4c for London ***

GFS mean at 108 @850 2 degrees colder for everyone than 00z expect 120 to be down to -8c for Scotland ( poss -10) S

So just to draw the attention away from the 144-192 period & show where the adjustments are occurring - nearly all models this morning create a significantly better ‘ARC’ of Cold CAA south through western Scandi - with the GFS last to latch on - The 96 charts - UKMO https://www.meteociel.fr/modeles/ukmo2.php?carte=1021&ech=72&nh=1&archive=0 Aperge https://www.meteociel.fr/modeles/arpegee_cartes.php?ech=6&code=0&mode=0&mode3h=&runpara=&carte=1 JMA (84) https://www.meteociel.fr/modeles/jma.php?ech=24&mode=1&nh=1&archive=0 GEM https://www.meteociel.fr/modeles/geme_cartes.php?ech=6&code=0&mode=0&carte=1&archive=0 So for Scotland & the NE - maybe even the midlands it looks like snow sinking south- For the south - the exit point of the low is crucial as for 48 hours post that the isolines probably won’t change - UKMO Goes ENE delivering the cold all the way south GFS goes direct East with a slight SE component drawing up warmer air - Difficult call - UKMO the favourite- S

The GFS gets to 138 & then just pulls the little shortwave west restricting any further southward advance - however that’s not to concerning as the bigger picture is a huge move to UKMO even on this run lots of snow for the NE!

Yes GFS now looking like the UKMO

Also 5 DAM heigher heights over Iceland @78 Snowline into Scotland @72. The track of the trigger low is correcting south on all models A good comparable of the change is the JMA 84 00z v the 96 12z ...

The ECM is in (my) expectation a snip progressive again leaving the 240 chart plenty of room to be a long cold spell - awaiting UKMO 168- however @144 thickness is very low in London about 522 DAM ... If we pan out like UKMO it’s a big cold spell with snow falling in Scotland by Thursday...

Morning all A spectacular opening to 2018 with this @ just 120 heavy snow/ showers moving South- we have also lost the warm Easterly The 18z is just a distant memory...

No mate it’s just because it’s the 18z GFS same as the woeful 06z GFS * Sh*t data & limited obs.

Forget the 18z & move on it’s clearly broken. HAPPY NEW YEAR EVERYONE

Have I entered the nostalgia thread?

This is why the ECM control is colder - the initial flow is more NE not Easterly

South Easterly

Hi mate The Tweet relating to the above is summarising a pattern shift whereby there is a substantial Scandi block setting up ( also running in tandem with the -EPO Pacific ridge its a 2 wave pattern allowing for the PV to become segmented as opposed to uniform The 10mb starts round but does become elongated allowing ridging up through the middle The Zonal mean chart showing a less aggressive stratosphere with the CFS runs all dropping a SSW through late Jan S

So now... the third ECM run that doesn’t plough the Atlantic through at day 9-10 240 chart is excellent - low staling to the SW & fresh CAA south through Scandi! Feb 91 esque keen eyed will note the SE UK drop -2c @850 from 216-240 in a slack flow - proper continental air / cold pool that is - rare as gold hens teeth.

EC 192 wipes out the mild & also wipes out the Atlantic ( R.E.M. yesterday’s fiasco ) infact its the best chart of the day ! 556 dam thickness west of Norway - awaits the 560 line to appear !