Model Discussion 12Z 25/02/13

[No Balls Like Snow Balls]

I am surprised that no one has mentioned the GEM in LA LA land. If you like a tease take a look lol

Edited February 26, 2013 by No balls like Snow Balls

[be cause]

Aint bad by the ECM! Something similar was shown by the CFS, however it brings it in much earlier at 174hrs. Hopefully it will have support in the ensembles later....

It only needs support in 'reality'

[Frosty.]

At least the 12z has stirred some interest with arctic air seeping southwards like a slowly dripping tap, the ecm 12z is synoptically the most promising at T+240, how often have we seen that this winter only for it to go pete tong, the ecm has been the biggest tease and given the most false hope all through the winter and has been overly praised for ultimately delivering very little or nothing. The Gfs 12z is showing something inferior to the ecm, more of a short sharp burst of cold before atlantic high pressure drifts east. As for the next 7-9 days, mainly settled for several more days before slowly trending more unsettled with temps returning closer to average, coldest in the far north with polar airmass close by and possible arctic air into the far north of the uk towards the end of next week but it's very easy to be cynical and dismissive about those T+240 ro T+300 range charts, the set up is unusual but terminally slow to evolve.

Edited February 26, 2013 by Frosty039

[stodge]

Evening all

People are, perhaps understandably, quick to dismiss the ECM evolution and it's certainly very different to GEM which is unlike anything else I've seen so far.

What it does remind me of is the GFS 00Z output from this morning and it does seem there are the two potential evolutions (amongst others) on the table. Both bring us to an E'ly or SE'ly but the question is the source of the air. I do think GFS is starting to show the jet returning north and that would be a natural evolution for the onset of spring so let's see if the ECM option has ensemble support and whether we see it appear again in coming output.

GFS ensembles look very solid for a benign spell through into next week but, as we know, that's not always conclusive.

[damianslaw]

Haven't posted much in this thread recently, largely due to the very static pattern we are currently languishing in, with little day to day change and no obvious signs of a significant pattern change within the reliable timeframe.

All models agree on the current high drifting away painfully slowly to the SE opening up an attack from the south/southwest, whilst at the same time we see a very robust high pressure cell developing over greenland into NE Canada as the polar vortex drops a lobe into scandi - some very very frigid air is poised to be tantaslingly close to the UK next week.

The outlook for the first part of March will depend largely on how the atlantic trough phases with the scandi trough - it looks a difficult pattern to call and the UK looks like being caught up in the middle. We could end up with a mild SE/S flow with rain struggling to make inroads across the country,or we could end up with a much colder unsettled outlook with easterlies/northeasterlies.

[Dunstable Snow]

Haven't posted much in this thread recently, largely due to the very static pattern we are currently languishing in, with little day to day change and no obvious signs of a significant pattern change within the reliable timeframe.

All models agree on the current high drifting away painfully slowly to the SE opening up an attack from the south/southwest, whilst at the same time we see a very robust high pressure cell developing over greenland into NE Canada as the polar vortex drops a lobe into scandi - some very very frigid air is poised to be tantaslingly close to the UK next week.

The outlook for the first part of March will depend largely on how the atlantic trough phases with the scandi trough - it looks a difficult pattern to call and the UK looks like being caught up in the middle. We could end up with a mild SE/S flow with rain struggling to make inroads across the country,or we could end up with a much colder unsettled outlook with easterlies/northeasterlies.

I think this is a sensible post. I think there is every chance the boundary between very cold and less cold/mild could well end up over Britain with some significant contrasts in weather being experienced across the country.

[Cheese Rice]

I'd say a middle ground solution appears most likely going by the models/ensembles. The far north hanging on to the bitter cold air to the NE with it drifting south to Northern England at times, the outlook isn't particularly inspiring for southern England which might explain the lack of posts on here, unfortunately the risk of anything wintry confined to anywhere north of the midlands *for now* .

I wouldn't rule at an easterly if we get the right angle of attack, a few of the GFS ensembles show this quite well.

Edited February 26, 2013 by Cheese Rice

[Summer Sun]

Excellent agreement to the 9th of March from the GFS ensemble tonight

The Aberdeen ensemble has a lot more scatter

[fergieweather]

I think this is a sensible post. I think there is every chance the boundary between very cold and less cold/mild could well end up over Britain with some significant contrasts in weather being experienced across the country.

That's certainly been the UKMO view for the past 2-3 days (i.e., looking ahead into the 6-15d period). They've consistently talked of a low threat of a widespread snow event potentially taking-shape "...somewhere across the UK" where this boundary eventually sits (and of course dependant on various other criteria), but stress 'low threat' currently. I doubt anything in the present set of ensembles will alter their broad view for now.

[Mair Snaw]

That's certainly been the UKMO view for the past 2-3 days (i.e., looking ahead into the 6-15d period). They've consistently talked of a low threat of a widespread snow event potentially taking-shape "...somewhere across the UK" where this boundary eventually sits (and of course dependant on various other criteria), but stress 'low threat' currently. I doubt anything in the present set of ensembles will alter their broad view for now.

Thanks for the update Ian, sounds like a forecasting nightmare....

[Weather Monkey]

Looking at the 18z upto +87 so far looking settled with high pressure sat over us. The GEFS for 12z show a similar story with the period 1-3 Mar where the divergence begins. Temps for South/South East showing little variation with a slow incline upwards in temps.

I don't think deep cold is what anyone should look for but as Nick S alluded to earlier at 1909:

On a positive note at this time of year you need to be chasing the coldest source of air and its there waiting to break through the UK's defences! 

Mar 06 and Apr 08 are the type of event I'm hoping we see in s/se. Be more than happy with that.

[weather_it_will]

Nothing like a good easterly in the middle of March to see the end of winter, or maybe this is how summer is going to be. LOL

[davehsug]

Nothing like a good easterly in the middle of March to see the end of winter, or maybe this is how summer is going to be. LOL

No such thing as a good easterly in March, they all tend to be just like we've had for the past week. You have to source your air well to the north to get anything of interest from now on really. Easterlies are no good now until we get towards May, when they can bring some pleasant warm weather away from the East coast.

[weather_it_will]

Easterlies are no good now until we get towards May, when they can bring some pleasant warm weather away from the East coast.

I have seen snow in May, so don't get your hopes up.

[davehsug]

I have seen snow in May, so don't get your hopes up.

Not from easterlies. Please read the post.

[LomondSnowstorm]

No such thing as a good easterly in March, they all tend to be just like we've had for the past week. You have to source your air well to the north to get anything of interest from now on really. Easterlies are no good now until we get towards May, when they can bring some pleasant warm weather away from the East coast.

You're basically right, continental easterlies are usually a waste of time when you get into Spring while northerlies can deliver snow even into May (or June 1975 of course). However, the holy grail (for us lowland Scots at least) of an Arctic sourced east or northeasterly can still deliver even into April, moreso the further north you go of course. This chart brought the biggest snowfall of the winter for most of eastern Scotland and 9 inches was recorded in some parts:

These are more exceptions that rules of course, similar to the insane cold spell of late November-early December 2010 which seemed completely out of season for a potent easterly going by the form books:

An initial Scandi trough with a deep cold pool was required initially in both instances.

[legritter]

Must admit it seems the same most days now ,everything cold is showing on last couple of charts .but we have to be in with a fair shout .we are still in feb JUST and march as delivered cold snowy synoptics on many occasions and even early april and mid april 1908 brought copiouse amounts of snow to lowland southern and central parts .there is in my opinion plenty in later modell output and hints from other data so lets all keep the faith going .if there is going to be a battleground come early march a weather war is welcome in our green and pleasant land .

[cooling climate]

No such thing as a good easterly in March, they all tend to be just like we've had for the past week. You have to source your air well to the north to get anything of interest from now on really. Easterlies are no good now until we get towards May, when they can bring some pleasant warm weather away from the East coast.

Totally wrong. Take a look through the archives. March 62 and end of March 52

to name just a couple.

[cooling climate]

Interesting development on the ECM t144-168 charts perhaps where the low to the north

develops between Iceland and Greenland allowing heights to build to the east of this.

On this run the heights sink back southeast but this could be a new development and

one to watch.

I am still confident of higher pressure to the north of the UK and a east/northeasterly flow

into the second week of March.

[lindy2017]

I have seen snow in May, so don't get your hopes up.

It snowed on my sons birthday it was in May...............

[Frosty.]

The Ecm 00z has snuffed out the cold potential (for now or permenantly?) since the 12z last night, the gfs, which didn't look as good as the ecm has done the same, the atlantic depression looks further north and deeper. I just wonder if we have reached the point where chasing FI cold is fruitless if the models are going to pull the rug like this. As things stand, the mainly settled spell will continue for a while yet with more sunshine than recently and temps getting closer to average but still with overnight frosts, the outlook slowly trending more unsettled from the southwest with freshening winds from the South and South East, pressure slowly falling next week with rain and showers and temps rising to average or a little above... I think the ecm has performed poorly recently, not many days ago it was showing a potent arctic blast for saturday whereas for the most part, the gfs looked more benign, I think the gfs is currently performing better overall, what this ecm op run will do for the next EC 32 day outlook, I shudder to think, anyway, it's nearly the start of the meteorological spring.

Edited February 27, 2013 by Frosty039

[Frosty.]

I am still confident of higher pressure to the north of the UK and a east/northeasterly flow

into the second week of March.

i'm not

[Gibby]

Good morning. Here is the latest report from the 00z output of GFS, UKMO, GEM and ECM for today Wednesday February 27th 2013.

All models show a fine and settled spell lasting through until about Tuesday or Wednesday of next week. In the mean time the UK will be governed by High pressure innitially centred over the North or just to the NW of the UK. Over the weekend it moves SE over the UK and away into Europe with an increasing SE wind next week. Through all this period all areas spare a few outbreaks of light drizzle would be largely dry with often large amounts of cloud but some brighter and sunny intervals too. Patchy frosts would occur at night should skies clear sufficiently and it will be rather cold generally, especially in the South.

GFS then brings fronts NE into the UK by midweek extending to all areas by the weekend with rain at times in winds slowly veering towards the SW with rather milder conditions than of late. Through FI today the weather stays unsettled and windy with rain at times and average temperatures before High pressure moves East behind a depression settling things down again at the end of the run, at least in the South.

The GFS Ensembles show a milder spell is on the way although despite higher uppers over the South through the next week things might not be realised at the surface under often extensive cloud cover and a cold breeze. Beyond that an unsettled spell for all regIons is shown with near to average temperatures trending rather colder again later, especially in the North where there is a lot of spread between members from later next week. The operational was something of a milder outlier for Scotland for a time next week.

The Jet Stream shows the split flow continuing for another week with the main thrust of the Jet held well South of the UK down over the Southern North Atlantic and Southern Europe before it starts to ridge North in the Atlantic towards the back end of next week.

UKMO for early next week shows High pressure slipping away SE through Europe with a SE flow developing over the UK. Fronts are approaching from the SW though these will probably not reach anywhere spare the far SW through this period. Near to normal temperatures would prevail under the cool breeze.

ECM today follows the same route with rain bearing fronts slowly moving North and East across the UK through the middle and end of next week with a chilly SE wind for much of the time before things turn rather milder with time as winds begin to turn to a milder Southerly.

In Summary there is good agreement on the pattern of events over the UK through the next 10-14 days. Small but subtle differences do exist between the models but they all point to another week of benign and in places cloudy conditions before the atmosphere is stirred by an increasing SE breeze as the High that's governed our weather for so long finally slips away SE across Europe early next week. Low pressure lying well to the South of the UK then pushes it's fronts NE into Southern and Western areas by midweek and to all other areas later meaning some rain at times for all by the weekend with milder temperatures likely to follow on behind under winds turning more towards the South or SW.

[ANYWEATHER]

Interesting development on the ECM t144-168 charts perhaps where the low to the north

develops between Iceland and Greenland allowing heights to build to the east of this.

On this run the heights sink back southeast but this could be a new development and

one to watch.

I am still confident of higher pressure to the north of the UK and a east/northeasterly flow

into the second week of March.

Yep ,Im thinking along those lines too. I do think that the models are not modelling anything to well in the medium term. I think by the weekend the models "may" show some battleground situations across the Uk by later next week...One to watch I think....I certainly dont think we will see any extensive milder weather in the near future...

Edited February 27, 2013 by ANYWEATHER

[Frosty.]

Yep ,Im thinking along those lines too. I do think that the models are not modelling anything to well in the medium term. I think by the weekend the models "may" show some battleground situations across the Uk by later next week...One to watch I think....I certainly dont think we will see any extensive milder weather in the near future...

A milder more unsettled trend though, as gibby just posted, can't disagree with an expert and faced with the gfs and ecm 00z ops, there does appear to be a new signal which has shunted the FI cold further north and east and allowed a more unsettled and milder regime to make significant inroads.