SMU

Another 2 positives - GFS control following the Operational - Also the Mean @102 has the svalbard shortwave more alligned SW instead of west- thus increasing the probability of the deep cold filtering south theough Scandi - S

Just to add to how deep the cold is- thats a nice toasty -9c @850 over london. ..

Very hard to say - something like the GFS just not as clean- GFS 150 bringing in -9c polar air to scotland- proper deep cold ! Deep snow by then for the hills !!

Ukmo isnt quite as good at 144 - maybe 7/10 but no means bad though--- hoping to see the GFS bring that deep cold south -

GFS to 102 is about as good as yesterdays euro 120 runs 2 upgrades from the 06z ( second one is important ) * Better amplification west of Greenland * Better flow allignment of the svalbard shortwave aiming the cold more directly SW instead of just west (12z v 06z) snap singularity

Hoping for a few flakes here tonight @160M - west kingdown @230M just 1 mile away!

If we look at the huge loop the GFS is creating the 18z isnt going to be far off the ECM cross model agreement at 114 tonight...

Indeed GFS 114 now close to the UKMO 120 - so lets see how far North the GfS can get the block !

Continued @day 7

ECM mean is solid to 192 - we just need to keep an eye on whether the ridge can actually get all the way to the arctic high the middle ground is ok -again as long as that wedge sticks over scandi !! Exciting times- If the ECM verified then the cold uppers would be slightly behind 2010 & need a couple more days to drop - but by then it that position you would get another 2-4 days anyway as the blocking is so strong-- Lets get the block first & cross model support ! S

^^ Its why I keep the faith that it can happen again although we need the GFS on board! I think Friday 00z where we are 72>120 we will know by then !! s

Not to derail the thread but roll on to day 2-3/4 etc! on topic - the fact Im referring to a chart from 33 years ago shows the average return on this chart- 1 every 33 winters or 99 months ! You would feel odds on that the ridge is 90-95% safe now at 96-144 - its just how vertical it goes with the ECM going full meltdown- that 144-168 evolution is still maybe 15-20% but at least its on the table... S

Dec 31st 1984.

In true cold spells That statement has been has been inaccurate pretty much 100% of the time!

For total northern blocking probably one of the best runs ever !! however lets get the ridge to 48>72 first!! JMA similar at 132 as well--

A virtual pint for the 1 key date in the archives we had an atlantic ridged into the arctic meeting an arctic high ( Not Greenland ! ) answers on a postcard!

So the GFS & its means are slowly becoming more amplified - Its like the GFS has been out on a Sat night & is trying to creep in the backdoor @4am! If we compare the 850 mean at 192 12z v 204 06z you will see the cold is much further west = less toppling ( Also 0c isotherm now elevated towards iceland...)

In the olden days there was a plot for pole / North atlantic was well 06z & 18z was woeful on these - hence my distain for these runs... They are not available any more

Thats the NH - its almost pointless looking at those stats as the impacts that we are looking at are under a microscope in 1 spot...

So a pidgeon step from the 06z but not enough to satisfy a full morph over to the euros remember we are not to worried if there 'isnt' a major block through Greenland- just enough of a wedge to swerve the jet back SE when the atlantic throws a bit more energy east- GFS PTB 17 is a good example http://www.meteociel.fr/modeles/gefs_cartes.php?code=17&ech=6&carte=1&mode=0 also NAVGEM 06z which is american goes close to the euros remember its not the initial height of the 552 line but the stability of the wedge into the pole that steers the jet away from the UK..

Big change upstream on the 06z @96- much closer to the euros..

If you look at the T2Ms for debilt the answer is yes- & some slack easterlies as well.. The atlantic partially making easterly inroads is favoured but a high probability of this not making the UK...

The updated 00z ECM mean at day 10 shows a further swing to cold- - Residual high pressure over the pole - weak high pressure over Greenland & Scandi - The core of the jet running across the atlantic then bending south East towaards Spain - Low Euro heights.. Thats a stella mean.

Still stalemate this morning UKMO / ECM / GEM v GFS ECM is the best run of the season promoting an increasing cold picture with snow in the mix GFS whilst poor initially still retains the heights over the pole past 192 Much to play for with the 'kick' of the jet very apparent in the euros now at 120 it wont be long before its all resolved... S

Great 18z out to 114 much better flow at 96-114 brings in the -8c isotherm across Scotty & -6C more wisespread across the UK- Pressure over Greenland better in situ & ridge developing over NE states better vertically alligned