Model Output Discussion

[grab my graupel]

Please continue to discuss the Models

The latest Model output can be viewed in the Netweather Datacentre: http://www.netweather.tv/index.cgi?action=nwdc;sess=

Brian

[ZONE 51]

no wind included!

Taking a look at the surface pressure charts from GFS 00z from midday today up to tuesday next(all are for 1200hrs)

wednesday

thursday

friday

saturday

sunday

monday

tuesday

[Jason T]

Well i think output this morrning, still looking an improvement with everything to play for. Fingers crossed,however a nice little summer breather this weekend. Just wish that jetstream would move NORTH. Lets see what the output through the next few days brings.

[mushymanrob]

re yesterday mornings post .... on monday morning the ecm 00z had the ridge building and staying put over or near the uk , hence the referance to the ecm's heatwave, that of course has gone. and the models had slipped away slightly but significantly from a prospect of a sustained hot spell. ok a day or two here or there was likely, but no prolonged spell.

this mrning prospects for something warmer, sunnier and more settled have moved back, as models do... and as some of the 'big guns' are suggesting pressure rise to our south is likely over the next few weeks, then prospects are there for something to evolve. indeed this mornings gfs 00z highlights exactly how a normal summer hot spell might develop... but its fi!

as for the ecm... i dont get it, it seems irrational and has little resemblance to the fax which is often regarded as more accurate out to +120.

[Gibby]

Good morning everyone. Hee's this morning's account of the 00zs from the big three.

The current cool and showery theme continues across all models until Friday with low pressure moving slowly away NE from our shores.

GFS on Saturday shows a warm front moving NE through Britain bringing rain and drizzle for a while early saturday and introducing moist, humid air. Western coasts and hills would be shrouded in fog and drizzle with the east and SE brightening later. Then on Sunday as winds back southerly very warm, continental, drier air is sucked Northwards with sunny skies and high temperatures away from the NW. By Monday a weak cold front moves slowly east bringing cooler Atlantic air but ahead of it the high temperatures could trigger some thundery showers or storms. By Tuesday cooler air has spread to all areas with some rain in the North. Pressure builds strongly in association of the Azores High which extends over Britain onThursday. Thereafter a temporary injection of lower pressure bring the risk of rain but fine and settled weather dominates for most of the time as high pressure lies over or close by. Temperatures would lift into the very warm or hot category by the end of the run with 30C possible in places.

UKMO brings the ridge across on Friday with the warm front following overnight Friday to give a cloudy damp start to Saturday for many with drizzly rain and hill fog widespread. Through the day and definately over Sunday clouds break up as drier air feeds into the south giving a sunny, very warm day for southern and eastern areas though the NW is shown to stay quite cloudy and misty. By Monday a cold front moves east over the UK bringing temperatures back down with a short spell of thundery rain before cooler fresher conditions reach all areas by Tuesday.

ECM is the stand alone model this morning. It follows UKMO up to Sunday but keep things very warm and humid then as the cold front and eventual thundery Low formation to the SW delays the onset of fresher air. Sunday would stay mostly dry and away from the NW become very warm and humid in strong sunshine. By Monday things will turn thundery down to the SW with quite heavy rain likely there with thunderstorms breaking out further east in southern England likely too. Then over Tuesday and Wednesday as the Low drifts North any remaining warm air is swept away east on the strengthening westerly breeze south of the low pressure centre with further rain at times. The run ends then as last night with pressure becoming slack over the UK with an upper cold pool trough keeping the risk of showers going in light winds and normal temperatures.

In Summary it looks as though the latter end of the weekend will become briefly very warm but a cool down will take place early next week with the risk of thunder heightened by the ECM solution. Then it seems a waiting game for the Azores high to rebuild in a more favourable way to introduce a more sustained spell of summer weather. GFS shows this well and although ECM is slower to indicate this we're not a million miles away from it developing by 240hrs.

[Turnedoutniceagain]

http://www.meteociel.com...;y=141&ville=Londres

Looking good for Sunday and Monday, followed by a return to average temps next week. Fingers crossed for Saturday - I'm camping out !!!

[Nick F]

ECM looks quite a bit deeper with the trough to the west of the UK early next week, compared to GFS and UKMO, which creates strong WAA and pulls very warm T850s of 20C+ into far S of England, which could perhaps bring temps into low 30s deg C if it came off,

... then a rather active cold front along a particularly steep temp gradient pushes the hot air away eastwards early Wednesday - which would result in quite a lively breakdown:

.... but given GFS and UKMO prefer a less amplified and faster trough to move in from the west, ECM's operational solution this morning may not be the favourite, and that deep low racing NNE over Wern UK next Weds seems a little far-fetched though would be possible based on the temperature gradient of the operational.

Going into FI, GFS suggests some amplification upstream after a short spell of cooler westerlies - which would suggest possibility of a ridge building across the UK from the S or SW, ECM up to t+240 keep a flatter flow across the Atlantic, with the a more unsettled and cooler westerly regime.

[Summer Sun]

34c In the south maybe?

Also this needs to be watched closely

[Harry]

34c In the south maybe?

Also this needs to be watched closely

Yo Gav, what's occurin'?! (sorry couldnt resist lol)

If those synoptics prevail the atmosphere will go BANG!!!!

[AWD]

Need the other two to come on board first before we can get excited with the prospect of Storms!!

Hopefully the 06z GFS will edge towards the ECM and bring Mondays trough through more slowly allowing fo a big bang!!

Outlook on all models is getting better by the day for heat lovers however!!

[Thundery wintry showers]

Yes, this possible "two fine days and a thunderstorm" type event is looking more impressive than it did over the last couple of days. Saturday looks cloudy, damp and humid for most despite the proximity of high pressure, but by Sunday the damp weather looks like becoming increasingly confined to the northern half of Scotland with warm sunshine coming through elsewhere and highs of 25-27C for some. I am also monitoring the possibility of some thundery downpours, which are showing as being focused over the Midlands and NE England on the current run but will no doubt change nearer the time, while a showery, possibly thundery, breakdown looks likely on the 27th. The hot thundery spell might even extend to the 28th in eastern and southern areas, though I think the ECM has rather "gone off on one".

After that, I can see growing support for a weaker westerly type with more frequent high pressure to the east, so staying changeable, warmer at times, with longer drier brighter interludes in between the rain belts- though again I'm not sure if this is a long-term change or a temporary one.

Before all of this, a mix of sun and showers over the next couple of days, although we will have a weak front moving down from the north which may bring a belt of relatively cloudy showery conditions slowly southwards.

[Harry]

Need the other two to come on board first before we can get excited with the prospect of Storms!!

Hopefully the 06z GFS will edge towards the ECM and bring Mondays trough through more slowly allowing fo a big bang!!

Outlook on all models is getting better by the day for heat lovers however!!

Indeed

Would bring some great storms.

On the flip side, that chart (Wednesday 00z) could potentially bring widespread damage and risk to life if it occurred. A drop in pressure of 15+mb in 24 hours is not that far off being classified as a bomb (Oct 1987 storm)

[Methuselah]

Indeed

Would bring some great storms.

On the flip side, that chart (Wednesday 00z) could potentially bring widespread damage and risk to life if it occurred. A drop in pressure of 15+mb in 24 hours is not that far off being classified as a bomb (Oct 1987 storm)

Very much indeed, Harry...Defo some signs of some upcoming excitement.

Did you get the storm last Saturday btw?

[Harry]

Very much indeed, Harry...Defo some signs of some upcoming excitement.

Did you get the storm last Saturday btw?

I did indeed

Sadly, it was just the one very loud boom. But some torrential rain, squally winds and lovely cloud scapes...as ever, I wasn't at home and did not have my camera with me

Certainly a better year so far than 2010...I've had 5 thunder days so far, compared to 4 in the whole of 2010!

You?

Edited June 22, 2011 by Harry

[Gordon]

Very much indeed, Harry...Defo some signs of some upcoming excitement.

only if you like that sort of thing

besides still plenty of time for models to do a complete turn and catch everybody out

probably won't but you never know

[Harry]

only if you like that sort of thing

besides still plenty of time for models to do a complete turn and catch everybody out

probably won't but you never know

Oh Gordon I have missed you! You must have loved 2010 - hardly any storm action to speak of (across the SE anyway)

Indeed there is plenty of time for a coalition model 'u' turn...fingers crossed from me though that it doesnt

Edited June 22, 2011 by Harry

[MisfitDog3]

Hmmm...some interesting projections on the aforementioned 'Low' development for mid week next week! Personally I think it's going to track much further north or turn out to be a false alarm. I suspect the High may stick around slightly more than we see at present.

[NUT]

France looks as if it may well get some humdingers of storms next week as cape for tuesday inparticulair is at -11! (No doubt it will change) some interesting times coming up countrywide this weekend and early next week for sure

[SP1986]

A more potent spell of heat over the weekend, with high temperatures, very high humidity, and the chance of some severe storms in the 6z GFS is to be believed. Unfortunately This would also come at a cost, with any chance of high pressure and warmth after this, dramatically reduced. Personally I favour the previous runs whereby the heat over the weekend wasn't as high, but more pleasant weather resulted afterwards.

[conor123]

The ECM is a recipe for the perfect thunderstorm to be honest, the GFS is rather cloudy here both Sunday & Monday morning which is dissapointing though hopefully the westward trend in the models today will continue!

[Backtrack]

Can't help thinking the ECM has over cooked the low by LOTS at T+168.

Anyone else think this?

[Eugene]

hopefully the westward trend in the models today will continue!

I guess you don't look at UKMO, GEM, BOM, NOGAPS, GFS 06Z ensembles then.

Edited June 22, 2011 by Eugene

[SP1986]

The runs make me wonder because following the 1-2 days of warmth we have, things return to below average for the forseeable future (see ensembles), and I cannot recall a time when below average weather gave way to an intense warm few days then back to below average, it's quite strange. So in my opinion the warm spell for the weekend will either be significantly downgraded (which is a very very real possibility, looking at other model outputs), or the post weekend outlook will become much better (which I think is the less likely option looking at the Atlantic Oscillations.

[Weather Boy]

Can't help thinking the ECM has over cooked the low by LOTS at T+168.

Anyone else think this?

Yes, it seems crazily deep to me, given the time of year and its proximity to the High. Does it ever get as windy as that at this time of year? Guess we'll find out.

[NickR]

The runs make me wonder because following the 1-2 days of warmth we have, things return to below average for the forseeable future (see ensembles), and I cannot recall a time when below average weather gave way to an intense warm few days then back to below average, it's quite strange. So in my opinion the warm spell for the weekend will either be significantly downgraded (which is a very very real possibility, looking at other model outputs), or the post weekend outlook will become much better (which I think is the less likely option looking at the Atlantic Oscillations.

UKMO, ECM, and GFS all seem to be forecasting a warm/very warm Sunday away from the NW... which models are suggesting a significant downgrade of this?