Winter Model Discussion - 11/01/13 00z Onwards

[Liam J]

I think we can safely say we STILL have no idea how next week will pan out with so many diverging solutions, unbelievable inconsistency at such a short time frame! ECM has changed to another solution overnight after being so bullish with the very snowy outlook and southerly tracking depressions, thankfully still a cold run but less snowy than previously but then the ECM looks quite scary in the later stages - low heights to the north + PV.

Perhaps by Sunday we'll have a more clear picture?! As Nick S mentioned the confidence in any of the outputs post T96 is very low, exceptionally low! Very much doubt we'll be any the wiser during the course of today so expect further drastic changes to appear within the outputs...

[Frosty.]

The biggest plus this morning is having the Gfs onboard with the cold outlook, massive upgrade since 24 hours ago with a cold or very cold spell next week with significant snow and severe frosts. Coming back to this weekend, there will be at least (a few cm) of snow tomorrow in the south, more especially on the hills such as the downs but further north looks dry and cold. sunday will bring snow showers in from the east coast across the eastern half of the uk, early next week more persistent snow looks like pushing southeast across the uk with significant accumulations and then the snow showers again spread west from the north sea, from later next week the weather could become dry with severe frosts and freezing fog or the battleground scenario with atlantic lows bumping into the cold air and bringing more snowfests. A very wintry 7-10 days ahead seems likely to me. It's a very complex picture though, all the models are showing quite different solutions but the general trend is still very promising for our first major cold outbreak.

Edited January 11, 2013 by Frosty039

[chris55]

EC det couldn't be further from the ensemble mean (144 onwards) from the 00z, will be interesting to see the ens this morning.

Det taking energy over the top where as the mean takes the energy underneath

(00z mean until it updates!)

Overall though another interesting set of 00z runs, and cold and potential snow is never to far away, but details uncertain.

Saturdays front looks like trending south this morning, but this will need watching.

[TEITS]

So where's Saturdays event gone??

South basically.

This is something a few or us expected really. Over the years you get to learn the biases of the models and this SW tracking further S always remained a possibility.

[SMU]

morning All-

saturdays snow is rapidly going south-

UKMO pick of the bunch this morning with the monday snow event then very cold with snow over the E & SE before at 144 another shortwave drops SE through ireland with a big ridge about to build to the NW of the UK-

GFS lots of snow opportunities to 192- & the ECM so so,

basically the crux of what we are looking for consistency wise on the 12's & 00zs tonight is where the block is going to land post 120 as that is crucial for our cold spell- somewhere NW is the guess but how much lattitude can it gain...

S

Edited January 11, 2013 by Steve Murr

[ITSY]

so a step back from ECM, 2 steps forward by GFS and half a step sideways by UKMO.

sounds about right doesn't it!

[SKYMAN]

morning All-

saturdays snow is rapidly going south-

UKMO pick of the bunch this morning with the monday snow event then very cold with snow over the E & SE before at 144 another shortwave drops SE through ireland with a big ridge about to build to the NW of the UK-

GFS lots of snow opportunities to 192- & the ECM so so,

basically the crux of what we are looking for consistency wise on the 12's & 00zs tonight is where the block is going to land post 120 as that is crucial for our cold spell- somewhere NW is the guess but how much lattitude can it gain...

S

Steve,

Do you mean south as in France or the south of the England. Many thnaks

[bluearmy]

Interestingly, if gefs have managed to get a handle on the situation, at least half are amplified to the west/northwest with a renewed easterlyish at day 8. That is in the general realm of the ecm mean anomolys. Lets see if the 00z are consistent?

[Jonan92]

so a step back from ECM, 2 steps forward by GFS and half a step sideways by UKMO.

sounds about right doesn't it!

Step back from ECM? I can't buy that as long as it develops high pressured to the north.

Interesting again the Chinese modele, the CMA

[Troubleatmill]

NAE is showing a rain to snow event for the south on Saturday especially along coastal areas, although Kent should see only snow before colder 850-1000hpa air and lower dew points set in, main events look to be heading into early next week, Monday, Tues into Wednesday as short waves drop through and slide by

Edited January 11, 2013 by Nick JB

[Frosty.]

Funnily enough, the gfs has been so off beam but it has a habbit of playing catch up and then becoming the form horse, maybe the ecm is showing signs of dropping the ball with it's trend to a more benign outlook, it still looks very cold and frosty though with freezing fog, we would have a good snowcover by then with ice days galore, I do prefer the gfs snowfest scenario this morning, maybe the gfs is suddenly ahead of the pack after lagging behind for the last few days, the meto update later this morning will give us the answers.

[SMU]

Steve,

Do you mean south as in France or the south of the England. Many thnaks

its sliding south with each run towards france- the PPN doesnt look like making the midlands now- generally south of the M4

S

[Severe Siberian icy blast]

South basically.

This is something a few or us expected really. Over the years you get to learn the biases of the models and this SW tracking further S always remained a possibility.

Oh I'm well aware of what normally happens , but the midlands is normally a good bet for this type of scenario , for the met to bring out warnings yesterday to say 5-10cm for some on high ground they must have been fairly confident on it, still time to change I suppose as these are hard to predict but certainly a shift south.

As for next wk , I think they STILL havent got a grip on it and if tomorrow's event changes inside 48hrs then I can guarantee Mondays will change.

[BLAST FROM THE PAST]

Just as GFS really jumps on board, the ECM jumps off t144. Here we go again

BFTP

[Blizzardof82]

Looking at this mornings output from an imby position and I cant help but feel deflated everything slightly further east so those saying GFS is a snowfest are wrong because it looks like rain for Bristol westwards.

[That ECM]

its sliding south with each run towards france- the PPN doesnt look like making the midlands now- generally south of the M4

S

Salisbury plane could be interesting for that. Bit of elevation and in the right area. Plenty more opportunity for other areas as we move into the early part of next week. What's more, need to get closer to the events to nail PPN.

[Gibby]

Good morning. Here is the report on the 00z output of the big four models from GFS, UKMO, GEM and ECM for today Friday January 11th 2013.

All models show a colder period developing over the weekend as Low pressure moves in towards the SW with an undercutting cold Easterly flow developing over the British Isles. After a benign type of day today rain reaches the SW later tonight and spreads slowly East over Southern England turning the rain to snow as it engages the cold air late tomorrow and overnight. The front recedes away South on Sunday leaving a cold East or NE flow with sleet or snow showers near the East Coast for a while, dying out later as a ridge collapses SE ahead of a new area of rain, sleet and snow on Monday as it moves SE over Monday. This then remains in situ on Tuesday as a change to clearer weather on a Northerly flow arrives in the West with continuing sleet and snow for the East.

GFS then shows a continuation of cold and wintry weather through much of next week with snow in places, more especially in the North while much of the precipitation will turn to rain at times in the South as milder air infiltrates from the West at times. Through FI this morning the cold and unsettled weather situation remains in place with deep Low pressure areas crashing into the UK and on each Northern and Eastern side of these sleet and snow will be widespread and heavy and disruptive in places. Over Southernmost areas some snow is also expected though down here this may turn to rain on occasion as milder air comes tantalisingly close, especially late in the run.

The GFS Ensembles show the operational as a slightly milder run than the member pack in the South as the milder air entrapped under the depressions pass through with many members showing rather colder positions. There is plenty of unsettled weather shown and with coldish uppers around some of this will fall as snow almost anywhere in the UK.

The Jet Stream shows a flow high over the Arctic at the moment and a weaker flow to the South of the UK. Over the coming week or so a strengthening flow over the Atlantic moves South over or to the West of Britain, turning East over Southern Europe in a week or so.

GEM this morning also shows cold and unsettled weather next week with sleet or snow at times as successive Low pressure slips SE over and to the SE of Britain at times. It too shows milder air flirting with the SW briefly with some milder, rainy periods here before cold weather return to all later. High pressure gradually becomes dominant over the UK late in the run with some very cold nights with severe frost likely then as the precipitation risk subsides.

UKMO for next week shows cold and unsettled weather continuing in as small disturbances (in it's case) running SE with rain, sleet or snow at times for all in a very cold week away from far Western and SW areas where milder air infiltrates at times.

ECM finally shows the first half of next week with the cold and unsettled flow with as described above but later in their run High pressure slips down from the NW, eventually cutting off the cold weather as returning polar maritime air topples round the High and down over the UK bringing milder and rather cloudy weather late in the weekend with a thaw.

In Summary there is still a cold spell on the way. I detect a lessening of the snow risk early this weekend as the rain looks like causing more of an ice risk rather than settled snow for many in the South. Through next week further opportunities for snow remain for many as SE moving depressions engage cold air over the UK. The pattern in the far South and West will be more marginal at times as milder air is close by to our shores. Later in the output GFS maintains the pattern as above while both GEM and ECM show a UK High pressure moving in from the NW which ECM slips South later to bring less cold weather and a thaw late next weekend in from the NW.

[tonbridgemole]

Here's the snow for monday

[Snowmadsam]

I expect models are becoming confused by the SSW (or it may just be me!), it is interesting to see the models alternate like this, soon we should hopefully have a solution (I hope!)

ECM to +144 - good

lets see what happens with the GFS 06 and 12z runs today...

12z GFS, UKMO and ECM will be VERY interesting to see in terms of model behavior...

[swfc]

Good morning.Having been on line for a few days and hearing and reading in the papers about a three week freeze up im slightly struggling to see it to be fair?Five days of cold weather with various snow options but beyond that who nos i guess..very complicated set up as said by other members but the lack of and substantial pressure rise to the north or north east has me scratching my head to be honest

Edited January 11, 2013 by swfc

[The Northern Ramper]

I really don't see the point of worrying about t144 when Monday is FI

[TEITS]

Looking at this mornings output from an imby position and I cant help but feel deflated everything slightly further east so those saying GFS is a snowfest are wrong because it looks like rain for Bristol westwards.

At the moment Wales/SW England/Ireland could miss out on snowfall during Monday with rain instead. However like I said this morning how far W the snowline will be on Monday remains very uncertain. However what looks likely is as this LP sinks S the colder upper temps will begin to back W during Tues.

[Wilxy]

well the 6z will be intresting thats for sure.

[Matty M]

ECM EPS quite poor with lots of perturbations showing the collapse of the high over the UK or westerlies. Also % going for easterly.

I really must question the reliability of the ECM and its EPS of late.

Although GFS has been getting slack, it is the leader at present IMO.

6z will be very interesting.

[bradymk]

So GFS changes to the ECM evolution albeit slightly further north, UKMO is good, GEFS ens not bad, ECM good but does get milder end of next week ECM ens - completely different to yesterday by the looks of it and some poor members, however the whole EPS suite have been pretty poor, changing day to day like everything else. Bottom line - all the chopping and changing is not helping and shows uncertainty is still at really high levels, plenty more changes to come but happy GFS is now extending the cold spell.