Model Output Discussion 31/07/14 onwards.

[bluearmy]

Given the ECM ens, it doesn't have much of a chance . Probably on the right track but will end up further east and a bit less amplified.

[IDO]

A D10 Ecm chart has more chance than a GFS D10 chart in my opinion, Ecm is the best model IMO so if the models show it and I think it has a good chance..I will show it!

 

 

Looking at the De Bilt 2m temps as the plume has a direct hit there to see if the ECM op has any support:

 

 

 

For there, the 2m temp is about 7.5c higher on the op than the ECM mean at D10. A big outlier. ECM has been notorious this year for over doing their heights around D9-10 so I was just pointing out that this was likely another false dawn. The D10 ECM mean is very close to the GEFS at D10:

 

 

[knocker]

A look at the ECM ens for next week.

 

A familiar upper anomaly (no intense low mid Atlantic) with an east/west orientated trough,  high NE North America and cold pool over Greenland. The jet running west to east over the UK.

 

An area of low pressure over the UK Weds and Thurs with the Azores high making the odd flurry north but is curtailed by the jet and the general Atlantic flow. Temps about average but the usual warmer as you go south routine.

 

The ECM is not looking at any substantial breakdown in this pattern, certainly before the end of the month.

 

 

[Summer Sun]

UKMO still going for a couple of calmer days on Saturday and Sunday given any sunshine it would feel warmer than of late

 

 

Though looking to our west and trouble is brewing for BH Monday.....................

Edited August 18, 2014 by Summer Sun

[knocker]

 

 

Though looking to our west and trouble is brewing for BH Monday.....................

 

Yup the GFS agres with that. Depression NW of Ireland at 12z Monday and a generally wet day. Tues the depression is south of Iceland 983mb and dominating the eastern Atlantic with strong to very strong westerly winds over the UK.

[Captain Shortwave]

At the moment the GFS/UKMO give a fine day for Saturday UK wide, whilst a front into the west of the UK on Sunday afternoon, the eastern half the UK should stay fine with good sunny spells. The GEM has an even shorter window with showers in the east on Saturday and rain crossing the UK on Sunday.

 

GEM

 

With uncertainty still here, Monday still looks hard to call, though unsettled looks more likely. It will be a question of how resilient the ridge of high pressure is. Whilst the GFS is wet and cool for the south of Monday, a 50/100 mile correction northwards of that rainband and then you are going to have a very different scenario.

16-18C across the UK, high 20s across the channel. wouldn't take much to get into that warmer air, it also shows the potential for a very active frontal system so high rainfall totals could be a concern as well.

Why mention this? Well it leads back nicely to this mornings ECM which gets the south of the UK on the warm side of the jetstream. Could mean a 7 or 8 degree difference in temperature for Monday.

Edited August 18, 2014 by Captain shortwave

[phil nw.]

Yes a slightly weaker jet would make a difference to the feel of things over the week end as it would see a stronger ridge and some warmth easing north at least for a brief period.

Looking at the GFS/UKMO currently though it's difficult to see the weather settling down for long as the next low approaches the west on Sunday.

 

The current Atlantic ridge being replaced by falling heights over Greenland next week with a westerly Atlantic pattern looking likely to establish.The better weather as usual would be further south between any rain bands.

 

 

 

 

 

[Frosty.]

The GEFS 12z control run, which I think is fairly representative of the output today, shows an autumnal outlook with the polar front jet pushing south into the north of the uk at times and a conveyor belt of depressions sweeping in off the atlantic. High pressure is maintained across the near continent with it's influence occasionally extending into the south of england but on the whole it looks like a changeable broadly westerly flow taking shape during next week, more unsettled and windier further north but at least temperatures recovering to nearer average and the south / southeast could possibly import some warmth from france during the next few weeks...end of august maybe a good example of this.

[ANYWEATHER]

The Atlantic has woken up, no point saying any other! The jet stream has been quiet for months, so now the penalty we are paying is for unsettled weather. The models show nothing else in there trend....    

[Frosty.]

They think it's all over..BUT the Ecm 12z op run is at it again with much warmer and more humid weather spreading across the south of the uk for a time next week with temperatures soaring into the mid to upper 20'c celsius, especially for the south / southeast of england where it could briefly become locally hot according to this run as 564 dam thicknesses clip the south , along with the very warm sunshine there appears to be a risk of thundery showers. The run ends with the azores high poised to build in across the south...another sniff of summery weather then, at least for the south...not bad huh

[ANYWEATHER]

They think it's all over..BUT the Ecm 12z op run is at it again with much warmer and more humid weather spreading across the south of the uk for a time next week with temperatures soaring into the mid to upper 20'c celsius, especially for the south / southeast of england where it could briefly become locally hot according to this run as 564 dam thicknesses clip the south , along with the very warm sunshine there appears to be a risk of thundery showers. The run ends with the azores high poised to build in across the south...another sniff of summery weather then, at least for the south...not bad huh :D"

"they think its over" No , its not over as regards Summer , some fine days are bound to happen. but the models are hinting at unsettled conditions.Pretty normal in the scheme of things.....

[Frosty.]

"they think its over" No , its not over as regards Summer , some fine days are bound to happen. but the models are hinting at unsettled conditions.Pretty normal in the scheme of things.....

I'm glad you changed your post since I believe there is a zero tolerance against taking the micky out of someone elses efforts on here. I'm trying to bring an upbeat mood here and only describing what the models are showing.

[ANYWEATHER]

I'm glad you changed your post since I believe there is a zero tolerance against taking the micky out of someone elses efforts on here. I'm trying to bring an upbeat mood here and only describing what the models are showing.

Look I don't take the micky out of anyone .You indeed bring an upbeat mood on here, Im just looking at the models...  and back to the models....

[mushymanrob]

it would be nice IF the ecm op varified, but it as yet got no support. its likely to be an outlier. its not beyond the realms of possibility but until theres support then its little more then eye candy.

[Captain Shortwave]

it would be nice IF the ecm op varified, but it as yet got no support. its likely to be an outlier. its not beyond the realms of possibility but until theres support then its little more then eye candy.

Hmm the ECM is probably a reasonable solution to low heights (dare I say it the polar vortex) setting up over Greenland, a mix of warm/very warm tropical maritime air mixed with cooler westerlies from time to time. The ECM op could possible get highs of 25-27C in the south at the start of next week. Not unusual for a set up like this

Anyway this warmth would be transient as the day9/10 charts show a return to near average temperatures. 

Edited August 18, 2014 by Captain shortwave

[damianslaw]

Models all showing a weak transient ridge building in come Saturday turning things generally more settled and temps back up to average - only average mind, but appreciably better than the days ahead.

 

Sunday looks a tricky call at this stage all dependent on how strong such heights become - a weak build will allow low heights to quickly crash into western parts by the end of the day and an unsettled Bank Holiday for all, however, a stronger build should be enough to keep lower heights at bay until Bank Holiday Monday and eastern parts may escape with a dry bank holiday 3 day period under average/slightly above average temps, western parts however look unlikely to escape from at least a wet disappointing Monday.

 

Next week - the jet looks preety strong on a westerly trajectory - an unsettled end then to an unsettled month with temps around average with wettest cloudiest conditions always reserved for the NW quarter of the country.

 

Longer term - September may start on a warm note thanks to a pulse of warm south/southwesterlies with the trough to the west -but with the strong jet an unsettled regime would likely persist.

 

I've said many times how the atlantic traditionally gains the upper hand through August - this isn't the time for heights to build in situ over the country and keep it at bay - however, they often do try to do battle in September especially in the first half and quite often win - but the atlantic always has the greatest lasting power.

[knocker]

The upper anomaly charts this evening are broadly speaking in agreement giving a modified zonal flow which is reciprocated in the jet stream. Taking the ECM the position of the jet rather inhibits any incursion of heat from the south thus average temps mid week with a bias towards the south as usual. This in a generally cyclonic synoptic set up within the westerly flow.

Edited August 18, 2014 by knocker

[mushymanrob]

Hmm the ECM is probably a reasonable solution to low heights (dare I say it the polar vortex) setting up over Greenland, a mix of warm/very warm tropical maritime air mixed with cooler westerlies from time to time. The ECM op could possible get highs of 25-27C in the south at the start of next week. Not unusual for a set up like this

Anyway this warmth would be transient as the day9/10 charts show a return to near average temperatures.

fair comment captain, but even if it did varify its a brief event in a sea of unsettledness.

[Captain Shortwave]

fair comment captain, but even if it did varify its a brief event in a sea of unsettledness.

I'm afraid so, looks like a typical westerly pattern, though there will be some warm sunshine at times, temperatures balancing out around or a little above normal after this cool spell ends this coming weekend. There's still September and even the first half of October where conditions can become warm or very warm before the decent from early Autumn serenity into the depths of storms and then eventually winter (well except for last year of course   )

[knocker]

A quick look at the GFS for the BH

 

Saturday

 

Low 994mb mid Atlantic with another low 1003mb Baltic. Ridge of HP over the UK. Temps high 60s in England and around 60F in n. Scotland.

 

Sunday

 

Low 985mb now about 400m west of Ireland with associated fronts into Ireland. Ridge of HP slipping into the North Sea. Temps in England mid 60s and mid to high 50s in n. Scotland.

 

Monday

 

Low now 995mb SW of Ireland with fronts crossing England. Temps actually quite high in England maybe touching mid 70s but dear old northern Scotland barely touching 60F.

 

And then downhill all the way.

Edited August 19, 2014 by knocker

[Summer Sun]

Saturday / Sunday still on course to give some calmer weather from the west so with lighter winds and any sunshine it would feel warmer than of late even though temps would still be down on the average

 

 

Temperatures still on the low side for the time of year

 

 

By Bank holiday Monday low pressure moves in from the west but at the same time we see some warmer air moving in from the south west so although BH Monday looks unsettled temperature should be recovering from the south

 

 

ECM also shows warmer air returning next week though it too shows an unsettled week especially so the further north you are from mid week the south sees pressure rising so here we would begin to see less rain and higher temperatures

 

Edited August 19, 2014 by Summer Sun

[knocker]

After the pretty dire chart from the GFS for next Weds a look at the ECM ens.

 

The anomaly shows no change with the trough concentrated to the west of the UK, HP over the NE North America and a cold pool over Greenland. The jet, rather weak. meandering between systems so the the overall picture of a westerly dominated scenario.

 

So middle of next week average temps but could be quite warm in the south with low pressure in situ for two or three days.

 

Outlook

Of course this is Mystic Meg country so not to be taken too seriously but it has the Azores high encroaching with increasing dominance by the weekend.

Edited August 19, 2014 by knocker

[Man With Beard]

GFS 12z - you have to laugh really - a decent jet till the end of the month leaving things cool (mainly) and changeable - then as if by magic, September arrives with the perfectly shaped high pressure and temps nearing 30C! Wouldn't be a surprise based on recent Septembers!

[Polar Maritime]

Again from the GFS, August remains unsettled and cool, With the Atlantic in full swing. Maybe the start of Autumn will bring something more settled and warmer.. Even so the Atlantic again looks to win out, With the High Pressure currently Model'd the wrong side of the UK.  Many more runs yet before any certainty or detail at this range. The Polar Vortex certainly seems to be ramping up now.

 

Edited August 19, 2014 by Polar Maritime

[mhielte]

I would have to agree with Polar Maritime's assessment of the output. However, seen as posts will mainly be about the short-term unsettled conditions, it is nice to see GFS providing some early autumn heat, just as the kids go back.

 

No surprise to see a strong jet to the north of the UK allowing the high pressure to build...

 

Shame it's at a meaningless timescale for now. If it repeats and begins to feature more solidly on the ensembles perhaps it'll be an Indian summer, but in the meantime it is back to reality...

 

Showers and longer spells of rain to come after a reasonable weekend for many, if a little cool. Once that low pressure gets out of the way another one is right behind to rain off the rest of the next working week...

 

So despite the hope on the horizon (thanks GFS!) there is still a lot of unsettled weather to come. Enjoy one last BBQ this weekend (although don't go as far as wearing shorts). Lets hope September brings a change in fortunes