SMU

FWIW the ECM feels about right to start the cold @day 6- its whether the deep cold can make it south of say Leeds etc- ECM looks good though- here is the UK chart- snow from the borders upwards

I will have a look at TN9s post ECM 120 pretty good.. but not half as good as this brutal NE snowstorm - oh to be somewhere like Lake placid !! Nothjng marginal for the whole east coast

Cheers the good old days I remember 2010 when there was some 50s on there over the UK

Just while it’s quiet anyone got the link to the old wetter charts we used to use about 5 years ago they were from the GFS & had the snow fall in pink & snow depths over layed with the number so uk would be white with a small 22 in the deepest snow areas etc ! it was a wetter2 link or wetterkarte or wetter de. edit found it. http://www1.wetter3.de/animation.html

The 12z Aperge looks pretty good only running out to 114

All 3 of the 12s UKMO / GFS / GEM are a bit saggy on the eastern end of the block- subsequently the cold is mixed out from the SE - not the best of runs considering the level playing field set up from the 00zeds especially the UKMO More runs needed.

But much better cold alignment at 144 with no kink in the way watch the cold rush SSW 144-168

Yes ( & for all watching the 12z ) This is the area to watch for a cleaner flow - ( & of course higher pressure over Iceland ) Notice the kink over Norway that’s essentially blocking the core of the cold coming westwards on the GFS look around T126 for a better flow also 06z was Lowish on data ( lowest run since Xmas day ) S

Whilst it may appear tame take it V the context of the last few runs watch the dip get deeper...

Feb 1996. historical event. There’s many more - Jan 82, March 13 & so on

For those interested in means forecasting then ‘mean’ changes across timelines is a valuable tool to use as it shows how SUBTLE shifts over a run can manifest in important changes. Its been well documented that when the GFS follows the euro ( UKMO today for instance ) it doesn’t usually jump ship but gradually transitions over a few runs- ( almost like it doesn’t want us to notice ) The 06z mean V 00z Mean 132/138 is a classic example of subtle shifts that unless scrutinised under the microscope get missed. so side by side no change ?? * look at pressure over Iceland - up by 5 DAM * look at the shape of the low over England because of the Extra pressure over Iceland the top end of the low is less circular ( almost squashed oval ) indicating more forcing southwards * look at the depth of the cold coming through Scandi - heights around 5-10 DAM which a better vortex lobe... Summary- 06z Ensembles will edge to UKMO .. Expect a good set...

Don’t worry about the FI part of 06z look at the air on the 144-192 part using the Theta E charts shows a better flow

A rare lie in today- almost as rare as that UKMO 168!!!! :0 :0 GFS 06z continues the Models increasingly better shape of the Scandi high from run to run with the deeper cold curvature aligning better as well... All we need is the ECM to wake up ! Remember the debilt ensembles may not be as useful as it to could be on the cusp of the warmer air ! Stick to the 500MB mean ! S

Morning all happy NYE The UKMO the pick of the bunch today with a strong enough block to the north at 144 to be forecasting heavy blowing snow in the extreme north - all to be moving SSE between 144 & 168- look at the deep cold being rammed into Scandi The ECM on the other hand is very tame with any heights to the north & is going to get heavily criticised if it’s wrong like December ( but plaudits if correct ) It does however try to make an event for day 9 being less progressive than yesterday’s -12z ** NB it’s worth noting that while progressive in the mid term over the UKMO the day 9 / 10 charts even with mediocre blocking to the NE holds the atlantic at bay & by 10/11 is creating more of a resilient fight - Its always been the way with the models to sweep away a Scandi block only then to gradually edge back west with time... A reasonable set of 00z with UKMO having a cherry on top... ( hopefully the 168 will update today ) S PS rem similar scenario Jan 13 UKMO > All

No worries - I thought by now people might trust what I’m saying knowing I’m not making it up GFS our to 192 - strong NE winds over the UK with the -8c isotherm approaching s

Hi John in the round the ECM performes the best however last few cold spells very progressive notice the significant dip V the GFS on the last cold spell 10 Dec ECM red GFS black

There’s always someone trawling out statistics. we don’t live across the whole of the NH - we live in a tiny portion of it - probably about 1000th the area therefor all the stats anyone wants to point out of irrelevant. Anyone paying close attention to the operational ECM this winter will know how poor it’s been. It was the worst model with the slider & indeed the run up to the slider- The GFS was relentless & ECM followed suit with the blocking - so whilst you can quote numbers across the globe here’s a typical fail from the last cold spell in true ECM progressive style. Forecast day 7 V actual ... & for fairness the GFS same run much much closer- where it matters - in the Atlantic. So no one is dissing it because it doesn’t show the desired output - it’s being dismissed because it’s performing poorly in our region... Please understand the method of why comments are being made before throwing out meaningless statistics.

Whilst the ECM op is a PITA at 168-192 the 240 chart is a typical feature of Scandi Highs with the Atlantic jet hitting a brick wall & being sent Nothwards - no quick return to westerlies there...

I ECM - just binned it again. fed up with looking at it waste of space output just as bad as the last cold spell.

ECM much better @192 with -9c air in a strong Easterly flow over England however it feels a bit progressive to me Infact my confidence in the ECM op this winter has taken dip- it’s been awfully progressive on all cold spells

We have lift off @168.....

^^^ GFS control...

The GFs mean -150 V 156 shows about a 2-300 mile southerly correction meaning more & more of Scotland are in the snow zone.. If the 06z was 6/10 score wise then 12z is 7/10...

I think the GFs is good so far with deep snow accumulating for Scotland at the end next week

So eyes down for the 12s historically UKMO is the lead in these scenarios.. watch for slightly better heights to the north at 120/144 circa 10 dam as well a better curvature of the isolines GFS 72 looks better to the North V the 06z but early days s