12z model discussion - snow or sleety rain?

[phil nw.]

A move back towards ECM and UKMO by 12Z GFS which means a better chance of a transistional Snow event for many parts of the UK except perhaps the South West and the extreme South.

Even after Friday there`s still a lot of PM air in the mix of the following lows and this could mean further Snow in the North,especially the Highlands which could have a few days of lying snow from these systems.

It`s good to see a few days of Winter sypnotics at any rate even if we don`t all get the lying Snow this time.

Edited February 5, 2007 by phil n.warks.

[snowhope]

I hope you just used Birmingham as an example of where it is going to snow north from TEITS as it is a big place where everybody knows. Now what you meant to say was North of and including Upton Upon Severn. (About 40 miles south) :lol:

Seriously though this is facinating watching at the moment, and I cant wait for each set of Models atm. Remids me of the easterly that appeared last year to completely dissapear off the charts well within the reliable time frame and then to re-appear a few models later.

All good fun and as we saw in the last little Snow storm we got, precipitation and snow fall can be very localised and changable right up to a few hours before it is due to fall. Cant wait for Thursday/Friday to see what the country gets.

Edited February 5, 2007 by snowhope

[Pennine Ten Foot Drifts]

I think there will definatly be snow, just where? remains the question. Most probably on the northern side of any precipitation moveing in....

Hey your at an alltitude of over 900ft, no need to get greedy now! :lol:

I must admit I'll be quite disappointed if I don't see a decent fall later this week (if I'm honest, just don't let the weather gods hear !). But I remember a similar setup from New Years Eve a few years ago where the models were promising loads of frontal snow, but, whilst we got about two hours of snow, it turned to rain and was just about gone by morning - a very chastening experience in terms of model predicitions vs. reality, and the models have been so inconsistent in forecasting this week so far that I'm still very reluctant to take anything more than likely trends from them.

[kold weather]

WW, your point about a 930mb low is a very good one (infact its about 929mbs...) do we seriously think that low will be as deep, or even close to that given they are a once in a couple of winter events, tohugh the FS seems to bring up several in a month normally!

Now what happens after on the op 12z run is totally dependant on the strength of that low, a monster low is more likely to bring up a bartlett/azores high set-up like the 12z shows which will also keep any zonality mild in nature:

http://www.wetterzentrale.de/pics/Rtavn2161.png

Also another problem the GFS looks like having is its probably underdoing pressure rises to our north as the LP's swing across the south of England. Nearly every model has a breif easterly intrusion bar the GFS which suggests it will be forced in line sooner rather then later as it starts to tone down on the strength of those Lp's downstream.

I do think the atlantic will come back in however I stromngly favor zonality that is rather cool in nature with the jet stream running mighty close to the UK, i suspect the GFS is badly under-cooking the AO signal over the pole, put it this way..every time the GFS predicted a change away from the present one it, its been wrong this witner bar once which was the large change mid-Jan.

So overlal its been utter cack...or as Steve.M said once, a crock of....

Edited February 5, 2007 by kold weather

[nick sussex]

The first euro model of the evening in the shorter term disagrees with the gfs and still looks like taking a feature across the south.

Heres the charts for the gme first.

http://www.wetterzentrale.de/pics/Rgme361.html

http://www.wetterzentrale.de/pics/Rgme481.html

And now the gfs.

http://www.wetterzentrale.de/pics/Rtavn361.html

http://www.wetterzentrale.de/pics/Rtavn481.html

If people are hoping for agreement this evening the early signs arent good for this!

Edited February 5, 2007 by nick sussex

[gobbyash]

Looks like a rash of showers heading into North/East Yorkshire.

Hope its snow.

gobbyash

[phil nw.]

The first euro model of the evening in the shorter term disagrees with the gfs and still looks like taking a feature across the south.

Heres the charts for the gme first.

http://www.wetterzentrale.de/pics/Rgme361.html

http://www.wetterzentrale.de/pics/Rgme481.html

And now the gfs.

http://www.wetterzentrale.de/pics/Rtavn361.html

http://www.wetterzentrale.de/pics/Rtavn481.html

If people are hoping for agreement this evening the early signs arent good for this!

Hi Nick,

Yes subtle differences even at 36/48hrs.the development and track of that trough to the SW still not certain.

[Stuart]

UKMO is starting to come out now

http://www.meteociel.fr/modeles/ukmo2.php?...=1021&ech=6

[wellington boot]

Flippin 'eck, the low out in the atlantic around 160 is pretty much a hurricane. In every way it resembles one, if you look at the wind charts and the cloud charts. If that hit us dead on, there'd be a bit of devastation, but we'd probably also get some mega heavy snow due to dynamic cooling under 930mb pressure

[The Eagle]

UKMO has snow written all over it at 60 hrs this evening. Its amazing subtle difference make a huge difference. :lol:

[TEITS]

Right it's about time I made a more detailed post on the 12Z so here goes.

First off many are talking about snowfall during the middle part of the week and yet some could see a light covering tonight as I shall explain.

The Latest faxchart for tomorrow morning shows a trough moving S along E coastal counties during the overnight period.

The conditions are certainly favourable for snowfall as the links below show

http://www.wetterzentrale.de/pics/Rmgfs122.gif

http://www.wetterzentrale.de/pics/Rmgfs128.gif

Im not expecting much but if you live in N Norfolk and wake up to a light covering don't be surprised.

Now onto Thurs morning when the fun could begin for some of us.

Here are the links to the movement of the precip

http://www.wetterzentrale.de/pics/Rtavn604.png

http://www.wetterzentrale.de/pics/Rtavn664.png

I said earlier the Midlands Northwards look favourable and here are the attached charts.

Looking at the surface temps, 850 hpa temps, dew points what I believe would happen from these charts is once the precip moves inland this will turn to snow for places like inland central Wales, midlands and then this risk pushes NE throughout the day with temps recovering behind the front to around 5C and 7C on the coast. Areas to the S of this line/ coastal locations, Ireland are more likely to see rain although snow could be likely at higher elevation.

[Jude_foster]

The first euro model of the evening in the shorter term disagrees with the gfs and still looks like taking a feature across the south.

Heres the charts for the gme first.

http://www.wetterzentrale.de/pics/Rgme361.html

http://www.wetterzentrale.de/pics/Rgme481.html

And now the gfs.

http://www.wetterzentrale.de/pics/Rtavn361.html

http://www.wetterzentrale.de/pics/Rtavn481.html

If people are hoping for agreement this evening the early signs arent good for this!

Ok Nick, Answer Honestly, If the rest of the Euros show what the gme shows, who do we beleive? Im an amatuer thats why im asking a very knowledgeable member.

Jude

Edited February 5, 2007 by Jude_foster

[The Eagle]

I think you will all agree this is the chart of the winter so far at 72 hrs :lol:

http://www.meteociel.fr/ukmo/run/UW72-21.GIF

[kold weather]

Nick, I wouldn't be suprised if that happens actually, I seem to remember a similar set-up in March 2006, tohugh northern blocking was far stronge rthe jet wasn't too dissimilar:

http://www.wetterzentrale.de/archive/2006/...00120060303.png

That was orginally progged to come in at a similar latitude that the GFS this one at only for it to be steadily adjusted southwards over the 48hrs into the build-up.

Its a very fine balancing act. if its struck perfectly somewhere could be hammered and i mean hammered but slight shifts can move that zone quite a lot. Even now the ensembles have some rather varying set-ups even as close as 48-72hrs, and i mean some quite alrge differences. The exact polace that we get a hit ib that Lp will make a huge difference and even now its a very hard call to make to be honest.

By the way i wouldn't be suprise dif we get a Feb 06 re-deux over the next few weeks given the jet stream state right now.

Edited February 5, 2007 by kold weather

[PB22]

The link Stuart gave...the 12Z UKMO is stunning if I've read it properly!

[Snow storm]

http://www.meteociel.fr/ukmo/run/UW42-21.GIF

Very hit or miss for the South. Fortunetly there are signs of improvement in the 12Z run. Fingers crossed.

[Weather-history]

UKMO 12z for 120 hr

Is this right?

http://www.meteociel.fr/ukmo/run/UW120-21.GIF

:lol:

[Jude_foster]

I think you will all agree this is the chart of the winter so far at 72 hrs :lol:

http://www.meteociel.fr/ukmo/run/UW72-21.GIF

WOW WOW WOW.... Your right that is a good chart.

Herts would definatley receive snow from that chart.... Better than the gfs 12z for my location anyway

Edited February 5, 2007 by Jude_foster

[Harsh Climate]

I must admit I'll be quite disappointed if I don't see a decent fall later this week (if I'm honest, just don't let the weather gods hear !). But I remember a similar setup from New Years Eve a few years ago where the models were promising loads of frontal snow, but, whilst we got about two hours of snow, it turned to rain and was just about gone by morning - a very chastening experience in terms of model predicitions vs. reality, and the models have been so inconsistent in forecasting this week so far that I'm still very reluctant to take anything more than likely trends from them.

haha, I remember that one.. It snowed beteen 8 Pm-1am before turning to rain, we recieved a foot of snow from it!

Edited February 5, 2007 by Jed Bickerdike

[Anti-Mild]

UKMO 12z for 120 hr

Is this right?

http://www.meteociel.fr/ukmo/run/UW120-21.GIF

Good God!!! It's a monster!!!

:lol:

[Snow storm]

http://www.wetterzentrale.de/archive/2006/...00120060303.png

Wow wow! If only a 12Z

Edited February 5, 2007 by Snow storm

[Jude_foster]

UKMO 12z for 120 hr

Is this right?

http://www.meteociel.fr/ukmo/run/UW120-21.GIF

:lol:

Are my eyes playing tricks

[TEITS]

UKMO

:lol:

Tamara

I kept on refreshing and I even deleted my temporary files because I thought I was seeing things .

[VillagePlank]

It's a monster!!!

. . . coming over the hill, it's a monster.

:lol:

[Snow storm]

I find it very confusing. The UKMO has picked up a fantastic channel low only 48 hours away, whilst the GFS shows nothing.

Which will be right?