SMU

I will take PTB 1 https://www.meteociel.fr/modeles/gefs_cartes.php?code=1&ech=6&carte=1&mode=0

The 06z evolution is spot on I believe a sliding system day 9/10 ish all we need is better curvature of the CAA through scandi - similar to the GEM

Thanks@Catacol 18z brings blizzards to NE Scotland poss transferring south

Cheers —

Can someone just post up the link to the UKMO 168 new phone - no links

A slightly underwhelming ECM 216 JMA is the Carlsberg run this eve https://www.meteociel.fr/modeles/jma.php?ech=24&mode=1&nh=1&archive=0 S

192 ECM expect a a very big slider scenario @ 216 !

Just to add to the model debate- ive posted a couple of times that the GFS stratospheric ensemble data had to 2 key dates in the means 1) New Years - peak of the current increase in zonal winds 2) 6th/7th the date at which the ‘dip’ in zonal winds aligns to the long term mean- In my world What this translates to is for a short while across that second timeline the stratospheric vortex whilst still strong isn’t the defining feature within the atmosphere allowing this winters signals to become a little more prevalent again- The Pacific -EPO ridge which has almost been quasi stationary will be kicking about creating the stark east west split across the states - Alongside this the Atlantic ridge trying to move N/NE out of the Azores.... It does look like that the 6-7th has become the focal point of the output as there is the window for a shallow high to ridge NE & settle towards Scandi- Its clear already that the chances are it won’t be a Proper scandi High - but rather a surface high ... Which ‘could’ be as useful as the real thing as it can deflect the jet SE as well as advert cold air into the UK from the East - Optimal dates where this works spring to mind - Jan 13 - Feb 96 So let’s see how that develops... Post that there’s huge divergence between what we are seeing in the NWP V what the GFS stratospheric data is showing which are polar opposites !!! Much to be resolved.. but a very nice T2M ensemble trend for Debilt today... S

An interesting debate - in which FWIW I would add my points- The Forum has has been around for 13 years - & with that teleconnections have really come to the forefront of the discussion for the last 5 years - They we’re always there however as time has progressed so more & more measures / drivers have been identified. The most crucial part of the understanding how it’s all morphed together ( which is still in its infacy ) in terms of * What teleconnection is a driver / cause & what is an effect - * Then once established what drivers carry the most weighting with respect to not only the global pattern but also the more ‘local’ pattern impacting the UK. What I see from the posts relating to all the teleconnections is that there is a Plethera of available data that perfectly illustrates the starting point of where the globes at- a T0 if you like of all metrics - There after though every reference point I see for what ‘may’ happen is derived from analogues & phases of what happened before - & how that ‘may’ manifest in the next 2 weeks or so- & how this marries up with the forecast outputs for the chosen uteleconnection ( MJO etc ) There are many inherent problems & assumptions with this - - The assumption that what happened before is likely to occur again - That the Model data & output for that metric is stable rather than volatile - & the trickiest relationship of them all which is how the tropospheric metrics interact with the biggest factor the stratosphere. As a result what I see is forecasts highlighting & punts based on current data blended with analogues & model data- which is on very shaky ground because the models are poor at all levels & the analogues are probably not valid anymore. So to invest a lot of time putting a detailed post together is really just a bigger more in-depth explanation of the global starting point.. What it boils down to is as highlighted so many times * We can’t forecast change. We’re awful at it-Just the same as the models * The analogues are out of date due to changing paradigms * There are to many unknown unknowns - ( think of an example - failure of -QBO last winter ) As a result of this - I don’t believe there will be any accurate forecasts in the next 20 years - ( for cold anyway ) - but of course some successful mild ones for El Niño + winters. For me the only way forward is to continue to monitor the stratosphere + strength of vortex & to investigate the teleconnections that are changing at the moment including existing ones - as the sample size is to Small I admire the persistence in believing that it’s a credible forecasting method - however sadly - there are just to many variables in the way of creating a manageable frame work in which to deliver consistency & Accuracy... S

Impressive UKMO in early doors! I will update some musings later remember 6th/7th January...

How much snow you got left? thats adding to the depth of your surface cold!

It’s freezing rain, however in heavier bursts sleet snow could be some wintryness in the SE as very cold -1.4c here already...

Will wait to see if it’s all rain but will 100% down to SALR - to deep a warm layer ...

Evening All Lets get the bad news out the way- The GFS continues to modify the deceleration of the zonal wind after New Years, the baseline on the ‘dip’ still occurs around the 6th-7th of Jan ( highlighted over the last 10 days ) & therefor would represent technically the best opportunity of some blocking around the mid latitudes.. its important to differentiate the fact that a HLB is pretty much off the table, & even now entering Jan - without an SSW the prospect / probability of HLBs is quite low ( note to all the -EPO ridge is MLB ) Also just today the GFS is not seeing any further deceleration post the 7th, replacing it with another spike of westerly zonal winds - further supporting the idea of no HLB- Where that leaves us is ‘back door cold’ - the regular polar North westerly or equally the less likely Easterly via some sort of pressure rise to the North east- The ECM is now toying with this at day 10 however the initial prognosis doesn’t give this high much depth so it could well be swept aside, however equally it could provide enough ‘steer’ to allow for some more sliders- All in all then - the background signals are poor especially given the EQBO - & we will be lucky to extract the max out of mediocre patterns delivering exciting but transient wintry patterns- 07th-8th is earmarked as our next opportunity for something significant... S

Will have a look later just walked in! it will correct south

Just driven home an enjoyable morning - snowline in Kent.. approx 200-250M as I’ve just come across West kings down & Theres still a light dusting down currwnt temp New ash Green 1.8c (WK ~ 1.2c ) S

Another slider incoming at T72 on the ECM !!!!

Heavy snow Eltham high street

Snowing in new Ash green

Snowing in new Ash green

Snowing in new Ash green

Flurries of sleet & snow eltham

Remember all radar colours ( rain / sleet or snow ) isn’t real !! It’s model driven!

5.1c now

5.9 here now & steadily dropping