Spring Model Discussion 18Z 6/3/13 onwards....

[shaky]

And to note the 00z was better than yesterdays 12z as an overall run so yes a good shift back on 12z. We are only talking slight movements here for this spell to become notable or just a cold week. It does make for good model watching

BFTP

Damn right!!lets hope for a further southward movement between 216 and 240 hours tomorrow!!

[cooling climate]

at least it 'turned' at a longer timeframe than the infamous gfs T72 about turn in feb. all three big 'uns have now had their moments. if we dispense post T144 (as ukmo goes no further), i would say the verification stats are supported by performance with ecm leading ukmo and then gfs.

This week the UKMO was definitely up there with the worst of them. Very closely followed by the Met

and their blinkered vision.

Onto the models and I would say FI is t144 with a very good chance of prolonged cold and more

snow opportunities. I try not to get into the if only it was Dec etc etc because its not its March but

had it been many areas could very well have been looking at a prolonged period of ice days.

[Average Joe]

Well, in the words of Nick Miller on the latest Beeb forecast, "nothing significant or disruptive" in terms of snow, and drier next week than this. So perhaps Cobra and the Army can stand down?

[nick sussex]

This week the UKMO was definitely up there with the worst of them. Very closely followed by the Met

and their blinkered vision.

Onto the models and I would say FI is t144 with a very good chance of prolonged cold and more

snow opportunities. I try not to get into the if only it was Dec etc etc because its not its March but

had it been many areas could very well have been looking at a prolonged period of ice days.

CC I've been quite harsh regarding the raw UKMO output, but all models go through good and bad patches. I think you're being a bit over the top regarding blinkered vision though.

We have been here before with the UKMO not going along with an easterly which did indeed prove the right call, that's why until the raw UKMO output comes on board then I'm always reluctant especially with easterlies.

In this case the UKMO was wrong but I'm confident it will return to 2nd place behind the ECM after this dodgy week.

[shaky]

Well, in the words of Nick Miller on the latest Beeb forecast, "nothing significant or disruptive" in terms of snow, and drier next week than this. So perhaps Cobra and the Army can stand down?

i dont understand how he can say non disruptive cos the charts are showing completely the opposite for monday!!but i guess you dont expect anything more from them considering there still 4 days left till monday!!maybe there forecast will change later on after viewing the 12zs!!

[Gibby]

Good evening. Here is the latest report of the 12z output from GFS, UKMO and ECM for today Thursday March 7th 2013.

All models show a change is on the way later in the weekend. Through the next few days the weather remains cloudy and quite unsettled with rain at times. Cold Winds though are waiting NE of the UK and they will start to feed into the North early in the weekend extending to all areas by late Sunday with rain possibly turning to snow for a time before clearer but windy conditions arrive on Monday with bitterly cold winds and occasional snow showers possible in the East. By Tuesday the winds will decrease and back Northerly with further scattered snow showers, especially in the East with widespread frost at night.

GFS then progresses through the rest of the week with a further small Low pressure sinking South in the cold polar air delivering further rain, sleet or snow in places as it moves South exiting the SE at the weekend. Through FI tonight cold weather only slowly gives way as winds back towards the West feeding less cold Atlantic air in with any precipitation falling from the sky will revert back to rain with daytime temperatures recovering with time. The warming process is complete by the end of the run with Westerly winds well in charge as Low pressure crosses East to the North with all areas seeing occasional rain, heaviest in the North.

The GFS Ensembles show that the cold snap is still very much on course with tonight's ensemble set rather in less of a hurry to bring milder conditions back to the UK with average values not achieved until right at the end of the run. With plenty of colder options on offer too changes look like they are going to be rather slow with plenty of Low pressure around giving the chance of rain or snow throughout the run.

The Jet Stream shows little change from previous runs holding it's position at more Southerly latitudes than is usual with a limited incursion North towards the UK of a wing of the flow moving SE over the UK in a week or so.

UKMO for the middle of next week shows a weakening Northerly flow over the UK with a High pressure cell close to the West. Scattered snow showers would be likely near Northern and Eastern coasts and other areas inland through the afternoons but frost at night will be the most notable feature with clear skies and light winds.

ECM finally shows a similar evolution to UKMO tonight with a ridge covering the UK through the middle and end of next week with dry, bright days and overnight sharp frosts with just the chance of the odd snow flurry near North facing coasts. Late in the run milder air attempts to dislodge the cold pool over the UK with limited success, at least in the South with rain at times. However one proviso to this is that very cold air lies very close to the North of the UK with further cold conditions with the risk of snow holding in the far North with the risk of this pulling back down over the UK soon after Day 10.

In Summary next week looks like it is going to be cold with widespread and sharp night frosts. Snow though is unlikely to be a major problem for many unless the Low pressure shown on the GFS operational materialises through the middle of next week. Far more likely is clear and crisp weather with some sunshine by day but a few snow showers near windward coasts with most areas staying largely dry. The transition to this cold snap will be marked by a strong and cold NE wind with significant windchill over Monday but only light winds likely thereafter. Longer term milder conditions are still shown to develop over time but the method and extent is still open to question at this range.

[Summer Sun]

i dont understand how he can say non disruptive cos the charts are showing completely the opposite for monday!!but i guess you dont expect anything more from them considering there still 4 days left till monday!!maybe there forecast will change later on after viewing the 12zs!!

Lets not forget as well they have a lot more tools at there disposal than we do. Nick wouldn't say "nothing significant or disruptive" in terms of snow unless there is decent confidence at the met office

[Gibby]

i dont understand how he can say non disruptive cos the charts are showing completely the opposite for monday!!but i guess you dont expect anything more from them considering there still 4 days left till monday!!maybe there forecast will change later on after viewing the 12zs!!

I think you will find Monday will be a largely cloudy or overcast day with little convection nor frontal activity affecting the South of the UK at least. There will be though a strong and cold NE wind though with big windchill factors rather than disruptive snowfall.

[The PIT]

What exactly are you talking about,better still what exactly are you looking at to make such a statement?

I guess ECM T240 which isn't zonal but may fool one or two people into thinking it is. Another cold spell coming up it's just a question how long it will last.

[Hammer]

I think you will find Monday will be a largely cloudy or overcast day with little convection nor frontal activity affecting the South of the UK at least. There will be though a strong and cold NE wind though with big windchill factors rather than disruptive snowfall.

Gibby since when do we know exactly conditions 96 hours or so away as if fact.

[SE Blizzards]

Latest CFS run, and the cold just keeps on coming until the start of April! I'm sure that model is Anti-mild!

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=96&mode=2&carte=0&run=10

[nick sussex]

I think you will find Monday will be a largely cloudy or overcast day with little convection nor frontal activity affecting the South of the UK at least. There will be though a strong and cold NE wind though with big windchill factors rather than disruptive snowfall.

Are the UKMO expecting the cloud shield from the low in France to effect any convection? If not then I would have thought the set up was condusive to some convection.

[Gibby]

Gibby since when do we know exactly conditions 96 hours or so away as if fact.

Because that's what the charts currently show. Things may well change over the coming days but I can only report things as I see them as I hope most of you know I always do.

[Snowman.]

RAMP TIME!

Ahhh just when it was starting to get good

[Gibby]

Are the UKMO expecting the cloud shield from the low in France to effect any convection? If not then I would have thought the set up was condusive to some convection.

Yes exactly that as the clearance SE is not a clean one with a hangback of cloud likely to last until later in the day as the winds back Northerly dragging down clearer skies.

[SE Blizzards]

RAMP TIME!

In the reliable time frame as well.

[bradymk]

+192 would be a massive frontal Snow event even if it was only in the East , it is bumping into embedded -10 850's , would likely be all Snow for some, March or no March trust me on that one

There is no -10 850's even in the east at 192. It is -8 850's, unlikely to snow during daylight hours. http://www.yr.no/place/United_Kingdom/England/Norfolk/long.html these forecasts use the latest ECM data and although probably not that accurate, dont show any snow event.

[LomondSnowstorm]

Are the UKMO expecting the cloud shield from the low in France to effect any convection? If not then I would have thought the set up was condusive to some convection.

As with last time I think the skew-ts will be the most instructive, I've only really looked at my neck of the woods but from Sunday afternoon through to Monday morning here it looks good for convective snow.

Actually looking at the skew-ts the cloud base does look capped to about 750hpa for the southeast and East Anglia through Monday, so somewhat limited convection.

[Bradowl]

As Gibby says......

GFS then progresses through the rest of the week with a further small Low pressure sinking South in the cold polar air delivering further rain, sleet or snow in places as it moves South exiting the SE at the weekend.

This is worth keeping an eye on, these situations can show up nearer to time.

[Summer Sun]

Gibby since when do we know exactly conditions 96 hours or so away as if fact.

The met office agree with Gibby as well only Monday is different at this stage

Outlook for Saturday to Monday:

Further rain for some on Saturday. Rain easing on Sunday but turning colder with the risk of snow in places. Dry, bright but very cold by Monday.

Those expecting heavy disruptive type snowfall could be in for a big disappointment

[nick sussex]

Yes exactly that as the clearance SE is not a clean one with a hangback of cloud likely to last until later in the day as the winds back Northerly dragging down clearer skies.

Oh right, well that would make sense then.If that's the case then the better chances will be during the evening and overnight.

I think we'll just have to see nearer the time how quickly that cloud clears and also whether that cold front sees an undercut as it slowly clears.

[ribster]

The met office agree with Gibby as well only Monday is different at this stage

Outlook for Saturday to Monday:

Further rain for some on Saturday. Rain easing on Sunday but turning colder with the risk of snow in places. Dry, bright but very cold by Monday.

Those expecting heavy disruptive type snowfall could be in for a big disappointment

As could those expecting any warm spring conditions! Temps close to freezing by day Monday, in a bitingly raw wind, delightful!

[Froze were the Days]

Lets not forget as well they have a lot more tools at there disposal than we do. Nick wouldn't say "nothing significant or disruptive" in terms of snow unless there is decent confidence at the met office

Also the MetO were correct for the generally dry spell in the last cold snap back around the 22nd Feb when a few on here were screaming for convectivity. Looks like a similar pattern to me.

[Guest pjl20101]

Latest CFS run, and the cold just keeps on coming until the start of April! I'm sure that model is Anti-mild!

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=96&mode=2&carte=0&run=10

Think the Bejing climate center are more helpful to be fair as they are more consistent, I find that particular model very choppy and a change type of model. Even Gavin p who hasn't posted here for a while doesn't rate CFS too much. What we really need is some stratospheric warming to increase any remote chance of settled warm weather. Having said that the atmosphere like I said in a previous post is in a niño ish kind of pattern so maybe that is why everything is higgledy piggledy currently.

[Captain Shortwave]

Also the MetO were correct for the generally dry spell in the last cold snap back around the 22nd Feb when a few on here were screaming for convectivity. Looks like a similar pattern to me.

It's a different pattern with colder more unstable air. Trouble is if you have frontal cloud cover overhead that kind of stops convection which might be the case here. When the cloud clears brighter weather will follow from the north/north east hence a sunshine and showers scenario, just when this occurs will determine how much snow potential we will get. If the cloud sticks until Tuesday we pretty much get nowt, if it clears quickly Sunday then there is potential from a very nasty north east wind.