Winter Model Discussion 18Z 19/2/13 onwards.

[Thundery wintry showers]

I recall reports that in early March 1970 snow stuck around for a week quite widely in southern England, in sunshine, with 850hPa temperatures mostly in the -7 to -10C region and surface maxima of 2 to 5C. The reason for this was a very deep snowfall on the 3rd/4th which came from a disturbance in the northerly flow. The most prominent example that I can recall from Tyneside was in early March 2001 when a three-inch snowfall on the 2nd stuck around for three days in sunshine. That spell was exceptionally cold by night but temperatures still got up to 2-4C during the daytime.

Looking over the UKMO and GFS runs, though, there are hints that we might end up with a cold anticyclone settling over us into early March, rather than something snowy coming down from the north. A cold anticyclone would be likely to bring dry sunny weather unless associated with an east to south-easterly flow in which case cloud off the North Sea would reamin an issue. The northerlies had pretty strong support on this morning's ECMWF run and its ensembles though, so the positioning of the main "thrust" of the northerlies is still open to question.

Before that, a NW-SE split looks probable for next week, with generally sunny weather over central, northern and western Scotland, much of Wales, and the western side of England, but generally cloudy weather for SE Scotland and eastern and central England.

Edited February 23, 2013 by Thundery wintry showers

[Mucka]

GFS seems to be slowly trending away from the Northerly for something a little delayed and more Easterly based, so more drab, grey, essentially dry cold weather no doubt.

This would be acceptable though.

[bradymk]

GFS seems to be slowly trending away from the Northerly for something a little delayed and more Easterly based, so more drab, grey, essentially dry cold weather no doubt.

This would be acceptable though.

except the charts you post above would certainly not be dry for most areas. Edit: Sorry Mucka, misread the last bit. Edited February 23, 2013 by bradythemole

[Panayiotis]

GFS seems to be slowly trending away from the Northerly for something a little delayed and more Easterly based, so more drab, grey, essentially dry cold weather no doubt.

This would be acceptable though.

I know we shouldnt be discussing what will happen on the 8th of March but you would find much more snow showers in that easterly than the one we are currently witnessing, low thickness and v.cold uppers would cause a lot of instability out in the North Sea and with the strong easterly flow those showers (which would be heavy) would be driven right inland, also a Thames streamer I would also think in those conditions would be developed. Again though nothing mild showing on the models.... Edited February 23, 2013 by Panayiotis

[Captain Shortwave]

@bradythemole and Panayiotis

I think mucka is saying that chart would bring snow, compared to the dryish easterly we have at the moment

Do love that chart, pretty much a bullseye shot of cold uppers

Edited February 23, 2013 by Captain shortwave

[Mair Snaw]

GFS seems to be slowly trending away from the Northerly for something a little delayed and more Easterly based, so more drab, grey, essentially dry cold weather no doubt.

This would be acceptable though.

OH IF ONLY WE COULD MAKE THE WEATHER DO WHAT THE CHARTS SHOW!!!!

[on the coast]

OH IF ONLY WE COULD MAKE THE WEATHER DO WHAT THE CHARTS SHOW!!!!

Just imagine if the black bit hit our tiny island one day. We can but dream. Cold March heading our way maybe.

[weatherguy]

OH IF ONLY WE COULD MAKE THE WEATHER DO WHAT THE CHARTS SHOW!!!!

Didn't you know? The charts control the weather!

(or so some people seem to believe at times )

[Mair Snaw]

Just imagine if the black bit hit our tiny island one day. We can but dream. Cold March heading our way maybe.

Yeah this place would go into overload, i guess one day it will happen but within our life time?? i get the feeling that this march is gonna be a bit different from last march with its warm sunny days.....

I dont think winter has finished with us just yet.. maybe time for one last blast.

[Mair Snaw]

Didn't you know? The charts control the weather!

(or so some people seem to believe at times )

No i didntknow that, i thought it was the express that controls the weather....the headline today says " COLDEST WINTER FREEZE OF YEAR" so from that we can decide that december 2013 will be mild!!!!!!!

Edited February 23, 2013 by bigsnow

[cooling climate]

Don't get too excited it may look good but could easily change.

Also if your looking for snow cover then where going to need the -13 uppers or lower with significant cloud cover.

I can't actually get my hopes up as I am in the worst location for a northerly.

ECM looks good as does the 12z but way to far out to say anything.

Yes agreed although -13 uppers at this time of the year would probably produce max of 0c to 1c in

sunlight, colder if cloudy. Its not so much the air temp as how much warmer darker surfaces are

with increased solar radiation.

In colder climates you can have 2m temps of -8c say and yet with a stronger radiation the snow will

still disappear this due to a process called sublimation or evaporation where a solid will

transfer to a gas without going through the liquid stage.

Anyway back to the models and I am hopeful that after the northerly push we will see a

continued trend on the ECM tonight of developing a potent easterly/northeasterly as we

go through the second week of March.

[chris55]

Plenty of interest for those looking for one last shot at snow for the winter season, details are changing every run, but the overall pattern has potential.

However GEFS has backed away from the colder pattern on the last few runs,

Has the ensemble suite picked up on the new trend or will we see a backtrack. ECM 12z will be very interesting, and after seeing Snowkings post from earlier with those Birmingham 2m temps from ECM we will just have to see which model has the better handle on things. Although the UK ridge GFS wants to keep in place looks a little shaky to be honest.

Taking UKMO and GEM at 144, the GFS looks to have the UK ridge a little to strong, and this is what is preventing those ensembles from going cold.

UKMO144

GEM 144

GFS 144

[Mair Snaw]

Plenty of interest for those looking for one last shot at snow for the winter season, details are changing every run, but the overall pattern has potential.

However GEFS has backed away from the colder pattern on the last few runs,

Has the ensemble suite picked up on the new trend or will we see a backtrack. ECM 12z will be very interesting, and after seeing Snowkings post from earlier with those Birmingham 2m temps from ECM we will just have to see which model has the better handle on things. Although the UK ridge GFS wants to keep in place looks a little shaky to be honest.

Taking UKMO and GEM at 144, the GFS looks to have the UK ridge a little to strong, and this is what is preventing those ensembles from going cold.

UKMO144

GEM 144

GFS 144

Some good charts there Chris. i would take the gem one as the best of the lot, im sure the next few days of runs will tempt us with some stunning stuff in FI but im sure this is far from settled yet.

[chris55]

ECM 120 hard to judge where it will go, but it looks to me that trough to the north should drop right over the UK? (although second guessing a model run is often futile)

[Summer Sun]

The high backs west at t144

Edited February 23, 2013 by Gavin.

[Mair Snaw]

ECM 120 hard to judge where it will go, but it looks to me that trough to the north should drop right over the UK? (although second guessing a model run is often futile)

Yep it will probably go east and then down toward Greece....... they always get our snow...

[chris55]

Shortwave dropping south, UK ridge less prominent than GFS. Impossible to call at this stage, but still an interesting outlook.

Edited February 23, 2013 by chris55

[Captain Shortwave]

Not bad at t168, -12 uppers reaching northern scotland, most of uk very cold with a northerly wind

[Cheshire Freeze]

Shortwave dropping south, UK ridge less prominent than GFS. Impossible to call at this stage, but still an interesting outlook.

Only one way from there.....

[Summer Sun]

Northerly incoming

[Panayiotis]

Northerly incoming

Gavin isnt that a northerly?

[Summer Sun]

The high edges back east at t192

Snow likely in the east looking at that

[Liam J]

Bound to be watered down in time but some really epic looking charts being played out for the beginning of March. The most impressive we've seen all winter for prolonged cold prospects! Yes it is still possible to have very wintry and unseasonable weather into March - Just takes something rather more special...

[Summer Sun]

t216 and t240 see's the coldest air to our east

[mountain shadow]

Its amazing how the models were indicating a Western based -NAO a few runs ago with the colder air in the Atlantic.

Now its shunted too far East!