Winter Model Discussion 18Z 16/1/13 onwards.

[The Weather Dragon]

I've seen enough of the output at +72 to even know that this outlook is far from settled.

12'>http://modeles.meteo...gfs-0-96.png?12

We have a lobe of PV to the SW of Greenland and a lobe moving into N Scandinavia. Now in my opinion the models are going to struggle which has the greater impact on our weather pattern. The key question is how much energy E will the lobe of PV over SW Greenland send across the Atlantic. Are the models overdoing this?

Im expecting even the UKMO/ECM to struggle and I wouldn't be surprised if tonights ECM is much better than the 0Z.

Have you seen the predicted temps though.

Eye - I wouldn't trust those predicted temps they are always a good 2/3 c overcooked for our area. Met had us for 2 today - didn't get above 0 here

Edited January 19, 2013 by Jonathan Evans

[Panayiotis]

Have you seen the predicted temps though.

http://www.meteociel...2-580.GIF?19-16

I have feel that the uppers and precipitation charts are far more reliable than the predicted 2m temps by the UKMO, also with -6/7C uppers over Wales with the added snowfall which has settled, I would expect the 2m temps to be lower than that, but as John says time will tell.

[Methuselah]

Come on, peeps! Some recent posts have been about as close to model-discussion as I've been to Angelina Jolie's G-string!

[Tim Bland]

For Tuesday now the SW and especially Wales will be crippled at 72hrs on the UKMO!

That ties in with the SE snow event on Sunday causing the south to be completely crippled over the next 3 days!

Agreed this could be yet another major snow event. Uppers / temps in the SW look a bit high but Wales east look ok

http://www.meteociel.fr/modeles/ukmo2.php?nh=0&carte=1007&ech=6&archive=0

http://www.meteociel.fr/modeles/ukmo2.php?nh=0&carte=1594&ech=6&archive=0

Before this even hits areas such as Gloucestershire / west mids etc will already be under over 20cm of snow because of tomorrow's front clipping them. People should stop sweating over the breakdown in Lala land and enjoy what's going to happen in the next 5 days.

[Katiewombat]

For Tuesday now the SW and especially Wales will be crippled at 72hrs on the UKMO!

That ties in with the SE snow event on Sunday causing the south to be completely crippled over the next 3 days!

For a non model reader. Please explain.

Many thanks

[TEITS]

Eye - I wouldn't trust those predicted temps they are always a good 2/3 c overcooked for our area. Met had us for 2 today - didn't get above 0 here

Reason for the predicted temps is due to the warming effect from the sea on a SW,ly flow.

Higher ground and inland parts of Wales might be okay but anyone near the coast of Wales, SW would likely see those predicted temps.

[Tim Bland]

Jet going south http://www.meteociel.fr/modeles/gfse_cartes.php?ech=204&code=0&mode=5

Could mean the next low undercuts?

Unfortunately not, plus there's no real block left to undercut

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=228&mode=0

Not much of a pv left so only a matter of time before GPs reload?

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=300&code=code&mode=0&mode3h=0&runpara=0&carte=1

Edited January 19, 2013 by Tim Bland

[shotski]

The 500mb Anomaly charts don't fill you with confidence if your looking for a rise in heights NW

[Troubleatmill]

Come on, peeps! Some recent posts have been about as close to model-discussion as I've been to Angelina Jolie's G-string!

angelina jolie!! best lady ive spent the night with only kiddin.................she was rubbish

[Snowman.]

Gfs doesnt get me jumpin for joy in Fi but thats Fi its not going happen.... right?

[bluearmy]

Eye - I wouldn't trust those predicted temps they are always a good 2/3 c overcooked for our area. Met had us for 2 today - didn't get above 0 here

Dp's will be higher than zero as ukmo raw has sw flow (winds will be just west of south = non continental flow)

Anyway, gem and gfs are different and no doubt so will ecm. The interaction of all these shortwaves and the long wave trough proving a headache.

[weather eater]

Come on, peeps! Some recent posts have been about as close to model-discussion as I've been to Angelina Jolie's G-string!

Please pete you can keep it, she looks like somebody had a fight with her lips, they are weird.

[nick sussex]

Alex Deacon on the BBC suggests no foreseeable end to the cold but you look at the outputs and think there is!

Both the GFS and UKMO look pretty intent on ending the cold by the end of next week however the route there begins to diverge as early as T72hrs with contrasting views of the Greenland area.

Both the GFS and GEM at T72hrs split the energy, indeed the GEM looks the best of the outputs at that timeframe in terms of cold potential, still waiting for the rest of its output to come out.

Edited January 19, 2013 by nick sussex

[phil nw.]

The 12Z runs so far give us plenty of cold with chances for further snow in the next 4 days.

The continental feature moving north tomorrow up the eastern side of the UK followed by further trough disruption in the south west late Monday will create snowfall in some places.

http://www.wetterzen...ics/Rukm361.gif

http://www.wetterzen...ics/Rukm601.gif

The pattern still looks a cold one after this showing decent agreement between the GFS and UKMO out to T120hrs.with the Scandinavian high forcing the weaker Atlantic trough towards the south of the UK.

http://www.wetterzentrale.de/pics/Rukm1201.gif

http://www.wetterzentrale.de/pics/Rtavn1201.png

However there are signs beyond that of the blocking to the NE finally easing away which would allow the winds to turn more off the Atlantic bringing less cold air in.

http://www.wetterzentrale.de/pics/Rukm1441.gif

http://www.wetterzentrale.de/pics/Rtavn1441.png

There`s still time for further changes at that range and even if current predictions were correct there`s no great warm up or return to a mild pattern suggested.The jet is modeled to remain very much on a southerly track and it wouldn`t take much in the way heights further north to renew the cold.

Meanwhile there`s plenty of Wintry weather in front of us for the next 5 days at least.

[Frosty.]

well the gfs 12z really poor in FI with mild zonal returning after such a cold promising start it just goes low pressure crazy, at least the meto will treat this run with the contempt it deserves. FI is still wide open and will include a lot more cold than mild considering what the meto have said today and the state of the strat in the next month. Lots more snow in the coming days at least.

That was a rank mild FI outlier if ever I saw one, next please.

Edited January 19, 2013 by Frosty039

[Ian Brown]

Alex Deacon on the BBC suggests no foreseeable end to the cold but you look at the outputs and think there is!

Both the GFS and UKMO look pretty intent on ending the cold by the end of next week however the route there begins to diverge as early as T72hrs with contrasting views of the Greenland area.

Both the GFS and GEM at T72hrs split the energy, indeed the GEM looks the best of the outputs at that timeframe in terms of cold potential, still waiting for the rest of its output to come out.

Yes I think today we have seen the GFS put back the return of the Atlantic again but at the same time the models are agreeing on one of the Lows finally tracking far enough North to edge the block away.

I certainly don't see a return to conventional zonality thereafter but can we finally see those Greenland heights as we head into Feb ?

[johnholmes]

The 500mb Anomaly charts don't fill you with confidence if your looking for a rise in heights NW

not too different to what I suggested in my post this morning. They have to change markedly if blocking is what you want. That can happen but currently none of the main 3 show much if any sign of that-cold zonality might be a quick rather flip description?

[UV-RAY]

Yes I think today we have seen the GFS put back the return of the Atlantic again but at the same time the models are agreeing on one of the Lows finally tracking far enough North to edge the block away.

I certainly don't see a return to conventional zonality thereafter but can we finally see those Greenland heights as we head into Feb ?

I'm very much hoping we see heights transfer to Greenland, it's been a pretty poor affair for a lot of areas in the NW. Though my concern is as we saw in December when a piece of the PV moved out of Canada.

[Froze were the Days]

Gfs doesnt get me jumpin for joy in Fi but thats Fi its not going happen.... right?

Has it got anybody jumping for joy recently (other than the 0z run which I missed) it keeps rolling out boring unsettled dross in FI, maybe like TEITS I should stop looking at it after 72z!

Edited January 19, 2013 by Froze were the Days

[Frosty.]

I'm very much hoping we see heights transfer to Greenland, it's been a pretty poor affair for a lot of areas in the NW. Though my concern is as we saw in December when a piece of the PV moved out of Canada.

I was hoping for a repeat of the gfs 00z which had a mega greenland high in FI and the arctic floodgates beginning to open above us, no such luck since playing the gfs slot machine you can get anything in FI.

[The Weather Dragon]

Why are we concerned regarding GFS - it hasn't had a clue over the last three weeks in the medium term - very poor performance. UKMO has been the king pin in handling this block - even here there has been some error, for example Mondays undercutting low is a much weaker affair than modelled a few days ago.

[SMU]

I think we will need a fast turnaround to see the atlantic return swerved away from the UK- It has happened this week & so it could happen again- however if it does move in fast it will be the end to a pretty pitiful cold spell-

A few days of snow here & there...

S

[Froze were the Days]

Even UKMO firming up on a breakdown towards next weekend, between Monday and then some east south easterly tracking fronts but whether surface temps will be cold enough for further wintryness is in question.

[bluearmy]

Btw, alex deakin said 'no let up for the foreseeable future which takes us well nto next week'. Thats not quite the tone some might have placed on it. Ian sums up the situation re the trough finally getting far enough north in our longtitude. In the meantime, those shortwaves undercutting and interacting with the lw trough are not making forecastng easy. It does look as though the cold will slowly loosen its grip as we head through the week, moreso the further south in the uk.

[The PIT]

Why are we concerned regarding GFS - it hasn't had a clue over the last three weeks in the medium term - very poor performance. UKMO has been the king pin in handling this block - even here there has been some error, for example Mondays undercutting low is a much weaker affair than modelled a few days ago.

Joint top performer for six days but third for five. Work that one out. Anyway FI breakdown stays well out in FI so lets enjoy the weather in the reliable time frame. Sliders chances of some decent snowfall.