Winter Model Discussion 18Z 19/1/13 onwards.

[Severe Siberian icy blast]

Maybe the 5th!!!

You seen the 18z NAE SSIB!

Lol yes I have of course !! But lets hold our fire because it can all change in the morning, if is still looking good this time tomorrow then we can look forward to another 5inches !!!

[BLAST FROM THE PAST]

The one thing the 18z can be good at is trend spotting , it's happened many times before, and this coincides perfectly with GP's and chiono's comments as if they've listened to them! Fi brings the greeny heights we have been looking for all winter . Lets see how long it takes for the rest of them to get to grip with what's round the corner .

Fascinating

No trend to spot, Feb is the month in this descending winter. Its coming [nicked that from GP], most confident month ahead Vortex on the move, could be a stormy end to the month.

BFTP

Edited January 20, 2013 by BLAST FROM THE PAST

[bluearmy]

looking through the ensembles and its game, set & match to the vortex.

Opp has very strong support now out to day 5/6.

Jason

really ? i thought there were more members not so keen than i expected. infact, enough to make me think i may have gone a bit early to proclaim an atlantic victory next weekend. still strongly favoured though.

[Ade]

Snowing now in cornwall - the last place to see any.

[TEITS]

No trend to spot, Feb is the month in this descending winter. Its coming [nicked that from GP], most confident month ahead Vortex on the move, could be a stormy end to the month.

BFTP

Lets hope so because in the medium range i.e +240 pretty solid support for mild SW,lys for the end of Jan.

As for Feb I shall do the usual and wait for it to appear at a sensible timeframe. All very well saying so and so will happen but it means very little if it doesn't appear in the model output in my opinion.

[Jason M]

Looking through at day 5 its pretty much game over on the 18z set IMO. Fair enough if you have a different view :-)

At 240 hours still not great tbh. Couple of useful ones and one that looks great but has poor 850s.

Awaiting the deep FI stuff to see if any trend (though I only tend to take much note beyond day ten when it looks grim).

Overall massive trend away from cold today within the ensembles. It seems mogreps and ECM ensembles agree as well, so its pretty much a full house.

As said earlier I get the sense that the model output is starting to settle down to a more normal state of reliability. Hopefully by the morning I'll be proved wrong.

Jason

[Jason M]

Just to finish off tonight, late FI does provide some support for Greenland high. Control run also goes with this.

Obv so far out that its not worth thinking about tbh, but the signal is there within the ensembles amongst the durge.

Jason

Edited January 20, 2013 by Jason M

[TEITS]

Not bad ensembles in distant F.I with many suggesting blocking to our N/NW. The upper temps may not reflect this on the ensembles yet but the synoptics are promising.

Still I shall await the mornings runs. I do feel as though some goalposts have been moved this evening though. What I mean by this is im sure I read some predicting the Canadian PV lobe weakening and the Siberian lobe extending SW and becoming the dominate force bringing potentially bitter NE,lys in the final week of Jan. This clearly isn't going to happen and quiet the reverse is going to occur with the Siberian PV being forced back NE. So excuse my rather sceptical posts this evening and like I said I shall await this to appear in the model output inside +192 before I start getting excited.

[BLAST FROM THE PAST]

Lets hope so because in the medium range i.e +240 pretty solid support for mild SW,lys for the end of Jan.

http://modeles.meteo...21-1-240.png?18

As for Feb I shall do the usual and wait for it to appear at a sensible timeframe. All very well saying so and so will happen but it means very little if it doesn't appear in the model output in my opinion.

Dave

Like I said earlier, lets see what models show come Thurs onwards. Also what's this trust in he models?

BFTP

Edited January 21, 2013 by BLAST FROM THE PAST

[Cheese Rice]

ECM coming out now up-to T120. Low nowhere near as deep as previous projections, if we do see a breakdown it's likely to be delayed yet again.

[Jason M]

No arguments this morning.

Every model, every ensemble agrees on a breakdown. Plus we have intra run agreement from last night.

Looks like Shannon entropy has left town :-)

Looks like a potentially lively period of weather coming up.

Jason

[IDO]

ECM very poor for cold medium term. At T240:

No sign of any fledgling northern blocking there. Just the seeming migration of the PV from Canada to Siberia, but painstakingly slow. All main models on board for a breakdown at the end of the week. GFS has some ensemble members making it slower than the op run, but inevitable either way:

The op appears to be progressive on the 0z run.

As far for the rest of the week, mainly cold, probably very little snow in the SE, the SW Tue/Wed with their last belt and Northern England some heavy falls today. Scotland maybe the best snow chances for the rest of the week. From the weekend very mild (12c on GFS in places), stormy and wet.

As for how long the zonal weather stays with us, it looks like a minimum of 7-10 days. GFS late in FI offering potential but nothing we could be confident about, due to the PV piece over N Canada remaining in place throughout the 0z:

[snow drift]

The big 3 having a similar trend this morning and we can all go back to our normal hobby of chasing cold 5 plus days away from Sat. Though it is not mild, just not as cold. Benign is not a word you would use to describe the period after sat if the output is to be believed. This week is not without interest with further places seeing snow fall and some heavy in places. It has been nice to have a break from the norm of chasing cold in the longer term and having it in the here and now.

So from sat we can go cold hunting, Short Wave dodging and hope GP Met and co are correct in their assessment that Feb will bring some more cold to the here and now.

[Timmytour]

GFS 0z still shows an Atlantic Low moving in an easterly direction on saturday.

I'd say the Fat Lady is booked, and ready to appear on stage, but nobody's handing her the microphone just yet.....

[shaky]

I dont think the end of this weeks breakdown is settled just yet!!

[bradymk]

No arguments this morning.

Every model, every ensemble agrees on a breakdown. Plus we have intra run agreement from last night.

Looks like Shannon entropy has left town :-)

Looks like a potentially lively period of weather coming up.

Jason

Maybe but im starting to think this breakdown to less cold is not a bad thing at all. The movement of the canadian vortex will create a period of more unsettled milder weather yes, but it will also finally create a good opportunity for height rises to our north west. Without the less cold period, it is unlikely to get any height rises to our NW and this current cold spell cant last forever.

[TEITS]

I dont think the end of this weeks breakdown is settled just yet!!

I think we have pretty solid support for this. However the very end of the week could be interesting with some incredibly low min temps before the warm up arrives.

A straw to clutch is this below.

http://cdn.nwstatic.co.uk/ensimages/ens.20130121/00/prmslReyjavic.png

Around the 5th Feb is when we could see the elusive GH develop if this trend continues.

[Cecil Hogmanay Melchett]

VPoor models this morning with a positive NAO developing and still a woeful profile to the north west,still.got a good 4inches of snow overnight which will stay until friday so best event of the winter here.

[Gibby]

Good morning folks. Here is my take on how the models shape up this morning taken from the 00zs of GFS, UKMO, GEM and ECM for today Monday January 21st 2013.

All models show the cold weather lingering on for the whole of the working week. There will be various fronts delivering the risk of snow in places early in the week, notably in the NE today and tomorrow while Southern and SW areas may join in latr tonight, tomorrow and early on Wednesday as further Low pressure and associated troughs disrupt as they move SE over the SW then down into France. By midweek pressure will be rising and the risk of snow will be subsiding as a ridge of High pressure develops over the UK for a time bringing sharp night time frosts but brighter days with some sunshine. By Friday cloud and wind will be increasing in the NW as winds turn SW with milder weather with rain reaching these areas later. England and Wales will probably hold on to the dry and cold conditions near the ridge for one more day.

GFS then shows a change over the weekend as troughs cross East over Britain, especially on Sunday in a strengthening SW flow bringing about a rapid thaw along with heavy rain followed by showers, wintry on Northern hills. From then on through the remainder of the run the weather stays windy, relatively mild and unsettled with showers or longer spells at times in strong winds. Late in the run pressure rises over Greenland and the UK turns colder again with wintry showers right at the end of FI.

The GFS Ensembles show a warming up and the end of the week to nearer to normal uppers. Later in the run uppers do trend back downwards again to levels just below the norm. There are plenty of precipitation spikes, notably at the transition to milder weather with changeable conditions shown thereafter.

The Jet Stream shows the flow continuing East across Southern Europe for a few more days before it ridges Northwards to our West to latitudes of 50-55deg North eventually crossing the UK and turning SE through NW Europe by next weekend.

UKMO for midnight on Sunday shows milder weather well established by then with a fresh SW wind, continuing thaw and rain moving in again from the West through the following day.

GEM shows a less mild scenario through the latter stages of its run with a slower transition to less cold weather, especially in the East through the weekend. Nevertheless, the pattern of a thaw and a good deal of rain with strong winds is shown with snow reserved for Northern hills in its latter stages as Low pressures cross into the UK.

ECM shows an active Atlantic trough moving East through the UK on Sunday followed by a run of long fetch SW winds bringing ever milder weather with rain at times, most heavy and prolonged in the North and West with just shorted cooler spells with showers likely at times later as cold fronts pass by.

In Summary the change to milder weather at the weekend is well and truly programmed to occur now at the weekend and before in the NW. There will be a few more days for snow to occur over the UK before pressure brings a day or two of cold and frosty weather. The Jet Stream then rides over the top of the ridge sinking it quickly away SE and bringing milder and strong SW winds and rain at times and a rapid thaw of all lying snow over the weekend. The pattern then seems set for a while of a traditional Atlantic feed of strong winds from the SW, with rain at times and some brief drier interludes of sunshine and showers.

[Frosty.]

The Gfs 00z saved the best until last this morning, apart from that, the breakdown later this week looks even quicker with less fuss and a much milder weekend with temps recovering to 7-9c with wet and windy spells, next week also looks mild, wet and very windy at times but with occasional less mild showery intervals.

[Paul_1978]

I dont think the end of this weeks breakdown is settled just yet!!

I don't think I've seen anything as nailed on (sadly). By T+120, all models have us in south westerlies.

However, GFS has shown Greenland height rises in FI a couple of times, and even T+384 is only 6th Feb. Don't forget one of the most famous UK snowfalls in 1991 was on 8th Feb, so there is plenty of time to get something else interesting in terms of snow in the rest of the winter.

Incidentally in Wakefield today we have approx 5cm, which for 40m ASL is pretty good.

[Polar Maritime]

The Gfs 00z saved the best until last this morning, apart from that, the breakdown later this week looks even quicker with less fuss and a much milder weekend with temps recovering to 7-9c with wet and windy spells, next week also looks mild, wet and very windy at times but with occasional less mild showery intervals.

It saved the best until last..last night to Frosty !

Yes back to normal affairs by the weekend, with a fast thaw to come there could be flooding in some part's of the country. Im very happy with this cold spell so far, with around 40cm level snow outside and still snowing, the rest of this week could bring some more surprises for some part's of the country. Im standing firmly by GP & RJS, they seem very confident, we shall see... the hunt for cold continues from this weekend.

[Frosty.]

The Ecm 00z is a bit slower with the breakdown and is not as mild a run as the gfs 00z but it's not cold either, somewhere inbetween with a more average feel with temps in the 6-8c range but with a few mild days here and there. I have a feeling that when we get to the end of this cold spell, the next cold spell will only be another 120-144 hours away, it just seems worse now because we now know this cold spell is doomed by the time we reach next weekend.

[Frosty.]

It saved the best until last..last night to Frosty !

Yes back to normal affairs by the weekend, with a fast thaw to come there could be flooding in some part's of the country. Im very happy with this cold spell so far, with around 40cm level snow outside and still snowing, the rest of this week could bring some more surprises for some part's of the country. Im standing firmly by GP & RJS, they seem very confident, we shall see... the hunt for cold continues from this weekend.

I know, I read your 18z post

[Severe Siberian icy blast]

The Ecm 00z is a bit slower with the breakdown and is not as mild a run as the gfs 00z but it's not cold either, somewhere inbetween with a more average feel with temps in the 6-8c range but with a few mild days here and there. I have a feeling that when we get to the end of this cold spell, the next cold spell will only be another 120-144 hours away, it just seems worse now because we now know this cold spell is doomed by the time we reach next weekend.

Couldn't agree more

This cold spell came out of nothing, it jumped on board with 144hrs to go , the models haven't picked up on the height rises yet , there having a hard time with the disintegration of the Canadian vortex , with it pushing into the Atlantic, get this wkend out the way and we should see changes.