lorenzo

Slowly falling snow here just now with a couple of cm's cover. Should make the M 8 a car park as usual !! Happy Days

Is it time to dig out the wonky Moscow chart again....

Good post BFTP - this is a cracking chart and vital for the set up, in the last cold period over the end of December the JS tracking south had massive influence over the longevity of the cold spell.

http://www.sat24.com/gb That bank in the NS is certainly thinking about hitting the East Coast...... Cracking picture Lady P http://www.sat24.com/Region.aspx?country=eu&sat=ir&type=loop The low is building on this looped set ...

Lots and lots of fuss about Easterly this, too much FI, too many saying it was nailed on, comparisons to this year and that - where 09/10 deserves it's own place in History - could be the Winter where our outlook on 'classic' seasons turned the corner back to the old school. I still think there is plenty of interest around this weekend prior to looking towards next... Unresolved issues of where the blocking will create heights, how the Siberian block will move, the atlantic with another failed knock at the door and possiblities of Polar Lows - oh and the North Sea throwing us the odd curve ball. Am sure it's still going to be a lot of model watching, cold fingers and toes before February even gets a look in..

Looking back through the thread this post stood out in regards to the current position on the models..

GFS 18z run trickling out now and the cold pool develops in a similar fashion to ECM, this weekend is going to be fun - Nearly as much fun as watching the charts and Model Thread implode hopefully. Looks like January is going to go out with some signature snowfalls

Great summary Chino, in your experience how quickly do the models adapt to this information (second warming phase) , or is it already factored into future output? Surely the FI timeframe is decreased with the uncertainty over the vortex disintegration?

Straight Northerlies are deceptive - totally agree here. More interesting this time is the timeframe of this event - longer lasting than previous. Although the caveat is there that they do not deliver, there was plenty of action around Edinburgh in the las Nrthly set up. Going to be an interesting week ahead.. The low over Scandanavia could turn things North Easterly.. Can already see the satellite page getting locked in for PL formation from Weds evening..

No dampener SP , at least we have part one in play = cold.

The models have changed pretty dramatically over night from a meandering mild set up to a cold one. So yes it looks like a cold spell is on the cards. The next 24 hours are interesting to see if all the models come on line with the same progression of the cold pool. From Wednesday > Thursday we have the pleasure of some Arctic air firing its way down towards the UK and projections are for this to last for 3-4 days. Temperatures and ppn are looking favourable for snow - even in a Northerly set up. So yes - cold is on its way back for what is looking like the first week of February. Sorry to disappoint.

Think folk are going to be a bit happier with the charts today..... Thank you Zonal Wind and MJO convection

Great summary GP, no mention of the AO and NAO signals though are they still in a state of indecision?

Plenty of precipitation on the way on the radar. Let's just see what it turns out to be...

Its a big fat stalemate ! And weather conditions are pretty benign dare I say Borrrrring !

This screen cap to me sums up the entire madness this week. Models flipping between runs, ensembles failing to get a grip, telconnections fuzzy. I think that they simply cannot compute the outcome of a monster battle and so many permutations on the result. This is at Thursday 2100 , I would say FI to anything after this time at present..

The stand off between east and west continues on this morning ECM. I think the models are stretched at present resolving the issue of where the main energy goes after interaction of the latest atlantic low with the boundary of the seemingly immovable object the SH. Glimpses of cold, glimpses of Eurohigh - it really makes every run throw up a chart each side of the cold / mild camp wish for or can debate on. Looking to the 27th is now interesting signs a few days ago on ensembles for another dip in temps, the polar pool of cold air finally moving southeast and setting up somewhere useful for cold. However at that point a euro high is sitting over us and essentially we are the block ! Fully expect later today to change again!

The NAO and AO are for me the most interesting part of this Winter so far, the CPC review of December highlights a couple of historic moments. '' This overall pattern reflected the strongest negative phase (-2.4) of the Arctic Oscillation (AO) for any December since 1950 . Over the Atlantic sector this pattern produced the strongest negative phase (tied with 1963) of the North Atlantic Oscillation.'' The Ensembles are potentially poised to replicate December again for both with the AO in particular looking like it may exceed the -2.4 it valued.

Anyone mention cold FI..... Siberian block collapsing after being chased down by a split polar vortex = very cold start to February..

Thank you Blitzen. Found this which I have also seen on the runs today.. looks familiar..

Lancia you mention the low pressure being spectacular towards the end of the month - being new to this and looking through the winter set ups from the guides area this synoptic is not illustrated. Correct me if I am wrong it appears unusual compared to what I have been looking at over the last 3 weeks. Would this create a platform for the Greenland High to re-establish itself first week in February? Are there any past winters where a low moving with this amount of cold has slammed NW Scotland?

Crystal cleal blue skies here. ECM continues to throw us a progression on the Scandinavia cold reaching us Weds 000, right on the edge of Fantasy Island on the chart timeframes though. This evenings run may just prove conclusive, especially if GFS gets on board with the cold spilling over the North Sea. Interesting thread also relating to SST in the north sea and their drop of 2.5 C in the last few days, this should also assist that 528 line moving west. Way out in FI the charts show another monster low from the atlantic from the NW this time fully loaded with cold air, due to my inexperience not seen this set up synoptic so no idea how thats going to play out, am sure I read last night though that these types of lows bring very decent snowfall if all else is set up. Ensembles show a dip in temps for Weds, then another decent tilt toward the -5 to -10 mark from 26th and 27th onwards. Could it be,we will be cold going into February?? Over on the Model thread the issue remains whether there is a Bartlett high or not, when there clearly is no sign whatsoever of such a thing..

Living near the east coast of Scotland the ECM provides a shiver this morning for mid-week and limited potential. The ensembles evidence 850 temps in the area of just cold enough, LS spotted on the t96 fax from MO the 528 dam line appears just off the E coast. Also ensembles show another dip in temps from 27th. SST for the North sea are also heading in the right direction - so definately potential for snow dependent on ppn. Not looked North West yet and not experienced enough to know what a cold low heading SE over the country would bring..