Winter Model Discussion - The Hunt For Cold -18z 17/12/12

[Panayiotis]

The approach of the low to the south, IMO has a much better angle to it and it seems deeper, question is can it deliver?

[swfc]

I want my easterly and i want it now.

Can the 18z deliver? Here we go, sudden onset easterly.

If it is going to happen the next 24hrs are crucial

18z out to 54hrs

zero chance of an easterly!!!!now that should do it

[roys]

I want my easterly and i want it now.

Can the 18z deliver? Here we go, sudden onset easterly.

If it is going to happen the next 24hrs are crucial

18z out to 54hrs

no model exspert but it looks to me that those highs could be heading south

[Weathizard]

That deeper secondary low to our South is squashing that AH attempts to rise down at the moment.

[LomondSnowstorm]

A very helpful shortwave:

By suppressing the Iberian High hopefully we can get a slightly longer term gain for the initial lack of an easterly flow (to MBY at least).

[Matty M]

The small low doesn't deepen enough to enable a pull back of the colder airmass to the north-east, but it would not take too much more intensification for that to be a real prospect.

[Weathizard]

Ahh the shortwave is just not strong enough, still a better run to my eyes within a reliable 72-96hrs

[TEITS]

This SW tracking along the S is causing me a real headache. The track and how this develops really makes a difference. As I said earlier the deeper this develops has a knock on effect on the Iberian HP.

[swfc]

That ridging from the south is a real ball breaker!!!.so near yet so far

[Weathizard]

Someone nuke the Azores high please! Always rises at the wrong moments!

[southbank]

The irony of all of this , all summer we waited for a Spanish plume only for it to arrive on Xmas day when we least want it , signal still showing on models for this Spanish plume

[Geordiesnow]

Although there is hints of something colder trying it hardest to push in from the east, the trend is quite strongly favoring milder air to win out albeit its not going to find it easy to win for sure.

Its going to be interesting though to see how this pan out, no doubt the detail will vary from run to run although you like to think in 24-48 hours time, we will know for sure what will happen. At this stage its 70-30 for the mild air to win out and if it does, it could be a very mild xmas although changes could alter how mild the air gets.

[Panayiotis]

The irony of all of this , all summer we waited for a Spanish plume only for it to arrive on Xmas day when we least want it , signal still showing on models for this Spanish plume

The 18z is still on the 22nd and updating, yes I know it shows a Spanish plume for this date but for Christmas day it could all change, however you could be completely right Very warm for the 23rd if this comes off! http://cdn.nwstatic..../h850t850eu.png Edited December 17, 2012 by panayiotis

[I remember Atlantic 252]

Am I the only one that thinks this 18Z is dreadful? I mean where has friday's rain come from? was bone dry on 12Z, this run seems to suggest 4 washouts in a row? surely wrong

[damianslaw]

Reliable timeframe 72 hrs tops at the moment, the shortwave development forecast for Thursday will have a crucial bearing on how things pan out thereafter, if it intensifies and moves on a southerly track then the colder uppers to the NE would have no problem making inroads into the north and importantly help to support height rises over Greenland as the parent low over the atlantic sinks further south thanks to weaker heights over the azores - but if a secondary low develops off the eastern seaboard this could scupper the chances of a colder evolution early next week, oh dear its a real mess at the moment, far too many variables to predict what the run up to christmas is going to be like.

The BBC seem very uncertain of developments beyond Thursday evening.

[Weathizard]

Don't like the 18z at all at 132hrs, Azores high is super strong, why now? Its like that annoying Aunt or mother in law at christmas, wretchid thing.

[swfc]

Am I the only one that thinks this 18Z is dreadful? I mean where has friday's rain come from? was bone dry on 12Z, this run seems to suggest 4 washouts in a row? surely wrong

it is pretty rank to be fair and showing nothing consistent

[Geordiesnow]

The 18z is still on the 22nd and updating, yes I know it shows a Spanish plume for this date but for Christmas day it could all change, however you could be completely right Very warm for the 23rd if this comes off! http://cdn.nwstatic..../h850t850eu.png

Very warm?? I would say very mild potentially with a very mild feeling wind but it certainly won't be BBQ weather with alot of Sea Fog and low cloud would probably dominate as normally the case with a set up like this at this time of year.

Interesting output and it will be interesting which airmass will win at least pre xmas - what happens after that is anybody's guess!

[Fred Sykes]

Right, that's it. I've had enough of this. Can't stand looking at the models any longer. I'm taking a break. See you in the New Year. Happy xmas everyone

[LomondSnowstorm]

The NAE again looks better at +48 than the GFS:

compared to:

[phil nw.]

The problem is the second low coming off the E.Seaboard at T48hrs this moves into the Atlantic and phases with our main trough.

The whole low complex then digs south and pushes the upstream Iberian ridging ahead of it.

Inevitably the mild air then gets pushed north across the UK after a struggle.

[cooling climate]

Couldn't give a monkeys with regards to the will it won't it easterly because for the vast

majority of the country it won't and those that do get something from it could luck to you.

I am far more interested in what may be developing after Christmas this is where there

is real possibities of a cold spell setting up.

[Panayiotis]

Very warm?? I would say very mild potentially with a very mild feeling wind but it certainly won't be BBQ weather with alot of Sea Fog and low cloud would probably dominate as normally the case with a set up like this at this time of year.

Interesting output and it will be interesting which airmass will win at least pre xmas - what happens after that is anybody's guess!

Ye sorry very warm for this time of year..

[bluearmy]

so the Russian ridge retreats and we get our own ridge, courtesy of the remnants of the RR and some WAA from the Iberian ridge. Can we claim this height rise as fitting in with cohen's theory or does it have to be the Russian ridge?

[swfc]

In all honesty things considered i think its time to look to the new year for a change in the current set up.granted a few tweaks here and there can make a vast difference but looking at the here and now "northern hem charts"i cant see any real push from the east making it across the uk in generall.If the north east gets a couple of days of cold fair enough but it would be a biblical straw clutch for me .imo

Edited December 17, 2012 by swfc