314 replies to this topic

[Radders]

Another close but no cigar situation from the 12z again. At around t140 I thought the floodgates might open from the east, but the atlantic is just to stubborn. Perhaps we'l see it budge later on the 18z. Big, Big ECM coming up.

[john mac]

Steve Murr, on 16 January 2012 - 16:18 , said:

Hum not a lot of Accuracy so far in this thread-

GFS much more akin to UKMO now-
http://modeles.meteo...12-0-114.png?12

UKMO good at 96 as well-
http://www.meteociel...96-21.GIF?16-17

ALSO very good UKMO 120
http://www.meteociel...20-21.GIF?16-17

GFS 126
http://modeles.meteo...12-0-126.png?12

WALL of cold building up to the NE & the atlantic low seperated from a smaller shortwave on its southern flank which is good-

S

You took the words right out of my mouth steve, with the low track much more NW-SE a bit more amplicfication too.

[Buzzit]

The GFS 12z flirts, but does not want the UK to have anything to do with the East. I am still of the opinion that the models cannot handle major synoptic change and will fight against influence from the East until the change is on top of us. The ensembles will be interesting but I doubt they will give us any definite clues. I think it will be on like Kong before too long.

[Frosty039]

Maybe a lot of snow for ne scotland if the ukmo 12z verified? trough close to ne britain and a NE'ly element to the windflow from a very cold source, maybe some snow showers down the eastern half of the uk on saturday? It doesn't look wintry for western britain but there is a chance for the east and northeast, I can't imagine the pattern will be pushed any further west, more chance of being shunted east.

[Steve Murr]

GFS is edging towards a snowfest for england > the midlands +NE/ E/SE at 192-

Doesnt look all that great in the big picture but when you see this-

http://www.wetterzen...s/Rmgfs1892.gif Uppers -2

http://www.wetterzen...s/Rmgfs1899.gif Theta Around 10-12C

http://www.wetterzen...s/Rmgfs1898.gif Surface dewpoints -2c

http://www.wetterzen...s/Rmgfs1894.gif Surface temps Zero & below

http://www.wetterzen...s/Rmgfs1893.gif PPN moving slow east...


The GFS is NEARLY NEARLY there & UKMO looks good-

Very positive this eve-
S

[shedhead]

happy days, on 16 January 2012 - 16:38 , said:

Its all very frustrating isn't it.We seem to be having numerous bites at the cherry regarding the anticyclone to the NE but the Atlantic just keeps shutting the door on us.
At least there is no sign of that jet blasting into scandy but the PV needs to back west and we need to see some energy dive to the SW of the UK to allow the high to drag the cold west.

Indeed HD, yet another close but no cigar run from GFS, but we've seen cold weather remain tantalising close to our E/NE on many occasions in the past - tapping into it is a different proposition altogether though. On
the plus side however it is at least likely to be in situ come this time next week, which is not something we've been able to say hitherto this Winter, so all is far from lost re Feb at this stage.

Edited by shedhead, 16 January 2012 - 16:49 .

[Zakos]

Yes, look at the bigger picture, not the fine detail which is almost certain to change.

GFS, run after run, upgrades the strength of the Russian high. It doesn't matter if we miss the initial easterly, the Atlanticcant hold it back forever, especially as the PV is being shown weaker and weaker each run.

Frosty039, on 16 January 2012 - 16:45 , said:

It doesn't look wintry for western britain but there is a chance for the east and northeast, I can't imagine the pattern will be pushed any further west, more chance of being shunted east.

Why do you say this? After GFS and UKMO have both shifted the pattern significantly west?

[reef]

Maybe Im missing something, but all Im seeing is a weak north-westerly at around the T+144 range as the jet weakens and attempts to bifuricate. It doesnt quite manage it though and the pattern then flattens back into more a WNWerly as a shortwave moves down from Iceland on the next jet streak?

More importantly, the core of the high pressure is well to the east of the Urals and the trigger low (along with the weak ridge extending from the high) is too far to the east. In the end all we end up with is pretty marginal uppers and a weak NNE drift for around 12 hours. There isnt really much cold pooling on the continent anyway.

[Weather wizard]

Steve Murr, on 16 January 2012 - 16:45 , said:

GFS is edging towards a snowfest for england > the midlands +NE/ E/SE at 192-

Doesnt look all that great in the big picture but when you see this-

http://www.wetterzen...s/Rmgfs1892.gif Uppers -2

http://www.wetterzen...s/Rmgfs1899.gif Theta Around 10-12C

http://www.wetterzen...s/Rmgfs1898.gif Surface dewpoints -2c

http://www.wetterzen...s/Rmgfs1894.gif Surface temps Zero & below

http://www.wetterzen...s/Rmgfs1893.gif PPN moving slow east...


The GFS is NEARLY NEARLY there & UKMO looks good-

Very positive this eve-
S

Steve I think you should find your nearest specsaver's dew points look all positive to me and all surface temps appear to be well above zero.

Edited by Weather wizard, 16 January 2012 - 16:54 .

[Optimus Prime]

Steve Murr, on 16 January 2012 - 16:45 , said:

GFS is edging towards a snowfest for england > the midlands +NE/ E/SE at 192-
The GFS is NEARLY NEARLY there & UKMO looks good-

Very positive this eve-
S

Looks too mild for snow for me with very little cold pooling across Europe. Atleast the signs are there won't be many more mild days left.

[Steve Murr]

I must have had the wrong dewpoints on my screen said -2 across the Spine-

Maybe the cache for 06z hadnt updated

S

[JonMillar]

Last three 12z runs for the 20th, 21st and 22nd.

GFS trying to shut the door on Friday cold with the ridge being a lot flatter that the 15th 12z albeit to the west of the flat 14th 12z, but the new low developing off the intensified Iceland low offering a tantalising second bite of the cherry on Saturday.

Attached Files

•  2012-01-20 Height 500hpa + SLP GFS 12z Model Output.xls   2.83MB   34 downloads
•  2012-01-21 Height 500hpa + SLP GFS 12z Model Output.xls   2.83MB   10 downloads
•  2012-01-22 Height 500hpa + SLP GFS 12z Model Output.xls   2.68MB   27 downloads

[Zakos]

Steve isnt saying that there is a snowfest, hes saying we edging towards one.

One or two more upgrades would see a snowfest, so Steve is correct .

[Steve Murr]

Optimus Prime, on 16 January 2012 - 16:54 , said:

Looks too mild for snow for me with very little cold pooling across Europe. Atleast the signs are there won't be many more mild days left.

192 is slightly to warm but your point about cold to the east is a mile wide- it could almost be called a no ball-

S

[The PIT]

Aaah a deep FI tease you get the feeding frenzy going tonight. Close but no cigar. In fact I'm going to complain to the royal society for the prevention of cruilty to snow lovers. The really cold air just sitting to the east in deep FI is really cruel. Just outside the reliable time which seems to be going unnoticed is a possible breezy period for North eatern and eastern coastal areas this weekend. So you get some good seas to photograph if not any snow.

[Steve Murr]

OP you are looking for a theta chart ideally below 10C in the contiental flow & probably sub 5 in a Northerly-

http://modeles.meteo...12-6-168.png?12

Its plenty cold enough for Frontal Snow turning to snow IF we we get a slightly more SE flow into a System from the atlantic-

regards
Steve

[The PIT]

If Steve is referring to T168 period, I can't get his charts to load snow seems possible with temps and dew points close to zero. If the rain is heavy enough you should get evapourite cooling as well to help things along.

Edited by The PIT, 16 January 2012 - 17:00 .

[chionomaniac]

Synoptically there is not far for the cold air mass boundaries to change for during the next few runs to leave us in the cold air.

And I think that everything will be a little further west as the negative zonal mean anomalies put a stop on the eastward flow.

Just for FUN, at T+192:



Reminds me of Dads Army. So close for the south.

Edited by chionomaniac, 16 January 2012 - 17:04 .
changed east to west- makes quite a big difference!!

[Frosty039]

Zakos, on 16 January 2012 - 16:50 , said:

Why do you say this? After GFS and UKMO have both shifted the pattern significantly west?

With the high just to the southwest of the BI, it currently seems unlikely, the gfs 00z was showing milder weather covering the uk next weekend but it has backtracked quite a lot, the ukmo 00z was showing a cold weekend and still is, infact it has upgraded slightly but this is only my view Zakos, these kind of charts have been rare this winter, I can't recall an instance in the last 6 weeks when the pattern has backed west bringing snow risk so we are potentially breaking new ground if it happens.

[KTtom]

http://www.wetterzen...s/Rtavn1441.png

The +144 chart is probably the best of a dismal set(12z GFS)! Nothing remotly wintry in that run, some innacurate posts IMO so far on this thread.

Still, its only 1 run!