General Model Output Discussion Thursday December 24Th:

[conor123]

Merry Christmas everyone, and what fantastic charts to wake up to, looks like if this North/North Westerly comes off then we will be hit by band after band of snow showers as the wind direction would be perfect.

Hopefully Tuesday/Wednesdays low will be a bit further north just because the South East have already had plenty of snow and us Midlanders just 0.5cm though even on the track currently being progged we'd get some snow so it's all good:p

Edited December 25, 2009 by conor123

[Lewis]

The 06Z trended around 50-100 Miles south in terms of Cold air-

At t123 the -5c line - which will be the approx location for the snow is across the M4 corridoor-

http://www.wetterzentrale.de/pics/Rmgfs1232.gif

If you review the 117 chart on the 12z then that will move either north or South-

Along the western boundry of that line ( I would plump for Southern midlands + southern wales would see around a foot of snow poss more) although for a change the key variable isnt the PPN amount its where the boundry is......

Can someone put a link up to the wetter or weather online snow depth link-

also an image of the total snow depth at t144 for the UK from the 06z..- I would go for a fat 40 or 50 somewhere along the M4 route heading west- cardiff ish......

For this to be an EPIC event & more widespread we need a slightly better curvature of flow + cold undercutting over the north sea- this would be driven by the trough to the NE of scotland...........

Steve

Merry Xmas Steve, and merry xmas everyone!!

Charts look fantastic is the above one comes off with wind speeds like that they would be less moderation off the N sea i think, so i could see White out conditions (and the entire E coast)

Fingers crossed,

Anyhow, Dinner time soon

bye

[SMU]

I really like the chart below.

Oh and is this the link you wanted Steve .

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=gfs&MODELLTYP=1&BASE=-&VAR=weas&HH=0&ARCHIV=0&ZOOM=0&PANEL=0&WMO=

thanks- running the loop its around 30cm of snow --- not much then.......

S

[qseghj6]

Last year at this time the models were not as reliable due to lack of data input over the festive season. As we are at the same period now is the same thing likely to affect the next few runs ?

[Methuselah]

And, don't forget everyone, the North Sea SST must be falling all the while...

[Bolton67]

thanks- running the loop its around 30cm of snow --- not much then.......

S

[Derp Patrol]

Well hopefully I don't miss out this time.. got absolutely nothing so far apart from a light dusting

[clark3r]

Merry Xmas Steve, and merry xmas everyone!!

Charts look fantastic is the above one comes off with wind speeds like that they would be less moderation off the N sea i think, so i could see White out conditions (and the entire E coast)

Fingers crossed,

Anyhow, Dinner time soon

bye

What about the south east corner? does that look more likely to be rain there in the south east?

[J10]

I have issued the Latest Skiing Blog here http://forum.netweather.tv/topic/59094-alps-forecast-8/page__gopid__1672523entry1672523

One thing of interest is the position of the frontal system as it edges up from the South West. I have attached thumbnails of this from teh GFS 06Hz run, as a snapshot, clearly the GFS has it the furthest south of the three 3 main players, but this retains so much potential for those area effected.

The Blog contains these thumbnails also for the weekend, and also concentrates Details for Alpine Regions.

Merry Christmas to all

Nadolig Llawen i Pawb

[Wales123098]

What about the south east corner? does that look more likely to be rain there in the south east?

I would say North London across to Cardiff and Bristol northwards would have snow, but im not a metrologist so i do not know thats a guss looking at the charts. The SE corner wont do as well from this as the Midlands and S.Wales will I dont think.

[clark3r]

I would say North London across to Cardiff and Bristol northwards would have snow, but im not a metrologist so i do not know thats a guss looking at the charts. The SE corner wont do as well from this as the Midlands and S.Wales will I dont think.

thanks for that info! things are very likely to change in the next few days! Merry Christmas!

[snowmadchrisuk]

thanks for that info! things are very likely to change in the next few days! Merry Christmas!

This is how GFS see's it at +126 hours.

[clark3r]

This is how GFS see's it at +126 hours.

wow

[kold weather]

I agree with Steve, possibly could be a good foot in the sweetspot from this set-up, very old school set-up.

Even here in the south the 06z GFS has become a lot more interesting as the cold air cuts in before the first front has even cleared the south which then makes things very complicated, but very interesting.

Anyway the longer term prospects still look good...once again a lot of uncertainty about the set-up but the general idea of a -ve NAO spell setting up is looking more and more probable, it is a matter of now of just how long the set-up can last but I see no reason why it should change too quickly...

0z ECM is very interesting between 216-240hrs, the high there could go either way, there is another flabby upper high in the Mid-Atlantic which could go on to take over and the motion of the PV southwards into Scandinavia would also agree with that however equally we'd be right on the western edge of any cold shot...most interesting.

Edited December 25, 2009 by kold weather

[MR EXTREMES]

This is how GFS see's it at +126 hours.

need the whole of that chart with snow flakes lol better than the north london northwards idear lol:drinks:

[Frosty.]

This is how GFS see's it at +126 hours.

Major blizzard for the south and a mix of snow/hail showers elsewhere, sensational model output this morning and a big improvement in FI from the 18z last night which shortened the wintry spell to around the end of next week. I am a bit concerned the models might flip flop a bit during the next few days due to lack of data from critical areas but hopefully it wont make much difference, MAJOR SEVERE WINTRY SPELL ahead if these charts verify.

[kold weather]

Also worth noting in this type of evolution we are once again at big risk from an attack from the SW by a Low pressure cell, the big difference this time is the block looks like holding the Cyclonic northerly flow for a little longer...though the ECM goes against that idea by allowing a weak (but likely very cold) ridge over the UK.

I'd imagine the south Midlands looking good at the moment, the south would probably get a lot of rain followed by a change around to snow at some point...

[Cecil Hogmanay Melchett]

Yes, as far as I'm concerned we can take the Greeny High to the bank.

The battleground placement is still to be determined, I think the models will trend this Southwards although the trend this morning has been to progress the core centre of the Low towards the SE, but my call for major snowfall remains Mid/South Wales, much of the Midlands (but not me, Conor or Mark Forster ! - too far North) and Central Southern England.

meto going for heavy snow north of england Ian.

They think the low will be further north.

[Solar Cycles]

meto going for heavy snow north of england Ian.

They think the low will be further north.

We can hope HD, but I'm with Ian on this one!

[bluearmy]

couple of points:

joe B showed an anomoly chart for dec/jan mid november that had a large positive anomoly iceland/greenland ridging towards scandi and an eastern euro trough. therefore the flow was ne across the uk and the coldest air went into eastern europe. the ridge came away from due north jan/feb which introduced the colder flow over the uk. i note that he blogged last night about the cold first fortnight of the new year in europe and he asked for 'brownie points' re getting the spirit of the forecast right, if not the detail. my take on this would be that the cold has backed further nw than he had forecast which is obviously better for us though not for e europe (bulgaria/romania/n greece.

the lastest T84 FAX shows the approach of the occlusion to be less exciting for the south than yesterdays T96. obviously we wont know exeters take on where the push of energy from the trough heads until we see T96/T120 tonight but it could be a classic chart this evening (many of you will see several at the same time!!). in the old days, the energy always got pushed back if it approached on a sw-ne axis with a resulting devonian blizzard. i think there are several factors to consider. the most important is to get a stronger kick from the trough to our ne to get cold air undercutting the warmer uppers spreading north. not too much though or the front will fail to get north of the coast. it will also help that the continent looks to get a cold couple of days ahead of the fronts. a se draw will be just fine for the south though you want to avoid to0 long a sea track as the north sea is still warm enough to modify the lower layers.

enough divergence in the solutions in the mid term to keep us 'on our toes'. splendid model watching times.

[492]

UKMO have just put out warning for snow on Tuesday.

[bluearmy]

meto going for heavy snow north of england Ian.

They think the low will be further north.

HD - they state that the precip is likely to be rain in the 'far south of england'. that covers their backsides nicely. they, like us, have no idea where the snow will be. een by sunday evening, if the evolution remains similar, we still wont be sure. thats why its so funny to see a few peeps 'slitting their wrists' after each run. thankfully, there doesnt appear to be too much dramatism at the moment but by sunday, this thread could be IMBYism at its worst.

[snowmadchrisuk]

We can hope HD, but I'm with Ian on this one!

In the sort of flow that GFS has lined up for us , Even if you didn't score from the first low , the setup is so unstable showers would likely be widespread . If we actually get to the point where we have 2 ten day cold spells within 5 days of each other it is pretty amazing in it's self . Infact the Highlands doesn't really warm up at all .

[J10]

Is this also a Hale winter?

[snowmadchrisuk]

UKMO have just put out warning for snow on Tuesday.

Yes , there going against the GFS though , that doesn't have the precipitation moving North until Wednesday , although it has to be said these events tend to be brought forwards a little as we get nearer the time.