Winter Model Discussion - 11/01/13 00z Onwards

[pages]

Ensembles show massive just how liable change is in the medium term. Only out to 90hr so far and already a 15mb difference over greenland.

[TEITS]

what are the chances of a westward shift in tomorrows runs ? 15% 20%

Funny you say this because in my opinion its quiet good, won't give a percentage though.

I shall begin by saying though that the track this LP takes is quiet unusual between +48 & +96. Looking at the NAE and in my opinion the front moving SE is quicker than the GFS is suggesting and possible slightly further W. As I believe this diving S LP might be further W I will be far happier if Mondays snow continues to be suggested for my location tomorrow because I want to make sure the precip even reaches this far E!

If the LP is further W than the models are currently suggesting then this could have implications further on. The LP further W could mean the E,lys that follow might be further W and this could mean the HP that develops as the ECM could have implications with the Atlantic LPs i.e underneath or over the top.

So at the moment we have good agreement of snow moving SE on Monday followed by a cold E,ly flow thereafter. However the models are a right mess afterwards and the two main questions is where and how strong will the developing HP be after the dive bombing LP and will Atlantic LPs go under or over.

[Carl46Wrexham]

The Azores high is being a hinderance here (as ever)

We could do with that high splitting over the UK with one half retreating SW and the Atlantic coming in at a NW-SE trajectory under the other half of HP to the NE

P.s ON THIS RUN you can forget LOW LYING snow west of about Manchester (this includes me). Uppers appear to be continually moderating for the monday event out west and it looks increasingly marginal and mixed out. Looks good east of this though and you should keep your lying snow for a few days.

Definately not good news for the South West...the last thing needed is more rain.

[Jason M]

At 120 hour mark ensembles are showing a clear tendency to build high pressure to our northeast over scandi. This makes sense IMO and is a logical way forward.

Time will tell :-)

Jason

[pages]

perturbation 10 looks good wedge of high pressure over greenland azores high send packing and slider lows. cold going to be locked in?

[bluearmy]

Just to correct a tweet ref from earlier re mean ecm maxes 5c latter stages ecm - updated london numbers mean maxes around 3c throughout fi.

Reliable? No idea but at the end of the fortnight it appers to show a lot of cold runs with the mean skewed by some mild ones.

http://www.meteo24.fr/fr/home/meteo-france-et-europe/passion-meteo/ensemble-de-previsions.html?eps=london

Edited January 11, 2013 by bluearmy

[goosey007]

Funny you say this because in my opinion its quiet good, won't give a percentage though.

I shall begin by saying though that the track this LP takes is quiet unusual between +48 & +96. Looking at the NAE and in my opinion the front moving SE is quicker than the GFS is suggesting and possible slightly further W. As I believe this diving S LP might be further W I will be far happier if Mondays snow continues to be suggested for my location tomorrow because I want to make sure the precip even reaches this far E!

If the LP is further W than the models are currently suggesting then this could have implications further on. The LP further W could mean the E,lys that follow might be further W and this could mean the HP that develops as the ECM could have implications with the Atlantic LPs i.e underneath or over the top.

So at the moment we have good agreement of snow moving SE on Monday followed by a cold E,ly flow thereafter. However the models are a right mess afterwards and the two main questions is where and how strong will the developing HP be after the dive bombing LP and will Atlantic LPs go under or over.

very informative ..thanks, I am more impressed that i understood it all...you will make a model watcher of me yet!

[Panayiotis]

perturbation 10 looks good wedge of high pressure over greenland azores high send packing and slider lows. cold going to be locked in?

From one member? Not enough support...

[TEITS]

If you want any answers from the ensembles then don't even bother, bloody clueless.

Example of this at +144.

[Skyraker]

From one member? Not enough support...

I dunno, West Brom do OK.

[Jason M]

Ensembles good to 168. Obv not perfect at that range but some coherence emerging for scandi high. One ensemble looked very much like METO 144 chart..............

Jason

[Froze were the Days]

If you want any answers from the ensembles then don't even bother, bloody clueless.

Example of this at +144.

http://modeles.meteo...-7-1-144.png?18

http://modeles.meteo...-3-1-144.png?18

Yep! complete opposites. All about the shape of the block after monday, UKMO. looks good but obviously ECM/GFS doesn't

[Jason M]

If you want any answers from the ensembles then don't even bother, bloody clueless.

Example of this at +144.

I understand where your coming from and given the divergence at 70 odd hours its a fair enough point, but having looked through them all at 168 hours there is a stronger signal for high pressure to our NE. The details vary as is to be expected but the underlying trend is there. This morning the ensembles were mental, and almost completely random.

It will all probably change again tomorrow though :-)

Jason

[bluearmy]

Ref te gefs - at T192, less than 50% have managed to get the atlantic through and i would happily recommend 11 of them from a perspective of sustained cold.

[cooling climate]

Looking forward to the morning with the UKMO and ECM in unison following

this evenings UKMO t144 chart and the GFS taking another small step or two.

[stevofunnelcl]

Id say its finally nailed on... Sundy will be cold!!! Lol. Monday onwards will all change slightly as to where exactly areas are affected by cold and snow, which is what makes the models and this forum soo bl**dy adictive.... All members will be sleeping like children on christmas eve tonight excited to see what subtle changes father gfs and his reindeer (ecm, meto, etc) bring. Some children who have been good will be soo happy and others will have a piece of coal;-)

replace bucket'o drizzle with that piece of coal

Get people further east to blow hard in a westerly direction, maybe blow a few flakes out this way

Edited January 11, 2013 by stevofunnelcl

[Jason M]

Ref te gefs - at T192, less than 50% have managed to get the atlantic through and i would happily recommend 11 of them from a perspective of sustained cold.

I agree, I think this whole saga has a way to run and I wonder if this first cold surge is just a taster. For the first time in days there is some sort of trend.

Jason

[Paul T]

The big concern I have is the extreme cold coming out from Canada/Greenland set to fuel the Atlantic Jet Stream from 168hrs+. It's generally acknowledged on all models that this will happen.

Surely that will put the kibosh on any longer term cold prevailing. The SW'rlys during Dec were fuelled by this. Its very very dull.

Edited January 11, 2013 by Paul T

[pages]

From one member? Not enough support...

No about 5 of them so thats 25%, looks like 4 may go on to give an easterly. haven't a clue what pertubation 11 will do, it has nice 1025 heights from scandie to greenland, but the vortex is powering up a 930mb low south of greenland.

[Richie V]

Well, so much for my reconing on this been a short term shot of cold. Looking like ive been totally disproved on the too much energy above 60N and not enough low heights to southern euro. Bitter cold with an ever elervating snow risk is here to stay for a good long while. Im man enough to admit I was wrong in the quick smash thru from the west, but hey, im only human...... I think!

Peace all, and...... Enjoy.

Ric

[Nick F]

As well as the risk of moderate snowfall spreading southeast away from western areas on Monday, 18z GFS shows a 515dam cold pool over the south North Sea drift SW across southern Britain on Weds, so a risk of more general snow developing later on Tuesday overnight into Wednesday towards eastern England, with snow showers following across the east coast.

With day maxes progged to be at or below freezing inalnd, I imagine places that receive snow Monday onwards will retain it for the rest of the week.

Even if it does turn milder next weekend, it's still a reasonable 5-6 days of cold and snowy conditions, though no 2010.

Edited January 11, 2013 by Nick F

[Ice Day]

I agree, I think this whole saga has a way to run and I wonder if this first cold surge is just a taster. For the first time in days there is some sort of trend.

Jason

Absolutely agree. GP's talking about the end of Jan as the main event. This would be a pretty epic aperitif!

[ChartViewer]

The big concern I have is the extreme cold coming out from Canada/Greenland set to fuel the Atlantic Jet Stream from 168hrs+. its generslly acknowleged on all models that this will happen.

Surely that will put the kibosh on any longer term cold prevailing. The SW'rlys during Dec were fuelled by this. Its very very dull.

For me i take heart that this is being diluted by reverse winds, ssw taking hold, jet slower so diving further se.....Well i hope...energy coming out of the Eastern Seaboard off the lobe of vortex should surely slow down and allow more heights building North....charts will hopefully show this soon.....

[Ice Day]

For me i take heart that this is being diluted by reverse winds, ssw taking hold, jet slower so diving further se.....Well i hope...energy coming out of the Eastern Seaboard off the lobe of vortex should surely slow down and allow more heights building North....charts will hopefully show this soon.....

How's the CMA looking this evening??? Must be out to 120 by now!

[weather_it_will]

Wide scatter of the ensembles starts after just day one or two, so not much point taking them seriously.

http://modeles.meteo...un=18&runpara=0

Edited January 11, 2013 by snow is falling