Model Output Discussion - 31/8/14 Onwards.

[Summer Sun]

Looking at GFS those in the south will see very little rain again next week, Scotland looks most prone to rain and stronger winds at times

 

[knocker]

A quick look at the ECM weeklies

Edited September 19, 2014 by knocker

[Captain Shortwave]

looks like potentially another stubborn ridge building towards the UK from day 6

This time it's centres over the south of the UK so much better for eastern areas which have been plagued by cloud. Apart from a couple of weak fronts and maybe some thundery downpours in the next 24 hours, rainfall looks rather scarce indeed.

[knocker]

Yes CS a quite marked N/S split on the ECM. Not that one should take too much notice of the detail at this stage.

 

[DTHFCJ]

more or less dry with some nice temps to boot

 

http://www.wetterzentrale.de/pics/MT8_London_ens.png

im loving this extension of summer like weather...its been very good here in the west

[Frosty.]

Tonight's GEFS 12z mean soon becomes anticyclonic again and stays that way across the south, just briefly becoming windier and more unsettled across the far north of the uk around the middle of next week with atlantic fronts brushing around the top of the ridge but high pressure surges in from the southwest / south and all parts of the uk become warmer and settled. This could mean fine and warm weather continuing well into october, the atlantic doesn't have the stomach for a fight yet, high pressure just keeps bouncing back.

 

Looking at the reliable timeframe, during this weekend we will all notice a marked change from humid and thundery to much cooler, cleaner atlantic air behind a cold front pushing southeastwards clearing all the filthy poor air quality and mist which has plagued some eastern and northern coasts. Atlantic high pressure building in from sunday and for much of next week it looks fine for the south, chilly nights though with a risk of fog and a touch of frost and then starting to warm up again.

[Summer Sun]

ECM shows high pressure in no rush to leave with a NW SE split likely to develop so some rain and breezier in the NW whilst the further south and south east you are its likely to remain drier with some sunny spells

 

[phil nw.]

Tonight's GEFS 12z mean soon becomes anticyclonic again and stays that way across the south, just briefly becoming windier and more unsettled across the far north of the uk around the middle of next week with atlantic fronts brushing around the top of the ridge but high pressure surges in from the southwest / south and all parts of the uk become warmer and settled. This could mean fine and warm weather continuing well into october, the atlantic doesn't have the stomach for a fight ye

t, high pressure just keeps bouncing back.

 

Looking at the reliable timeframe, during this weekend we will all notice a marked change from humid and thundery to much cooler, cleaner atlantic air behind a cold front pushing southeastwards clearing all the filthy poor air quality and mist which has plagued some eastern and northern coasts. Atlantic high pressure building in from sunday and for much of next week it looks fine for the south, chilly nights though with a risk of fog and a touch of frost and then starting to warm up again.

A good summary of the outlook there Frosty.

The latest runs incl.gfs mean keeping the jet well north for the next 10 days at least.

Days 5 and 10 mean

http://www.wetterzentrale.de/pics/Rz500m5.gif

http://www.wetterzentrale.de/pics/Rz500m10.gif

A lot of mid latitude blocking across the Atlantic around 45-50degs N keeping the unsettled conditions to mainly the far north west.

It looks like the notable dryness of September will continue for many.

[knocker]

Looking a bit further ahead for a sign of any major changes. The anomaly charts all appear to be heading in the same direction with HP over North America and the UK, albeit not strongly positive, and a trough western Atlantic with a broadly zonal flow. The NOAA 8-14 tending this way as well.This would not indicate a major incursion of the Atlantic but rather intermittent bursts within the overall timetable.Temps generally average or above, Essentially maintaining the status quo.

 

I'm afraid the charts are a complete hotchpot as usual. Quite character building although a bloody nuisance.

Edited September 20, 2014 by knocker

[Polar Maritime]

Yes the Atlantic will only effect the far North for now, While the South continues warm and dry, Especially the S/E. Later in the run the GFS is hinting the Jet to make a more Southerly track by Months-end, With the Atlantic having more of an influence on the UK..

 

[johnholmes]

more or less dry with some nice temps to boot

 

http://www.wetterzentrale.de/pics/MT8_London_ens.png

im loving this extension of summer like weather...its been very good here in the west

 

you lucky people, over here dull, damp much of the time, days with sun being few over the past 8 days, one gorgeous day and one afternoon.

Looking forward to tomorrow with a cleaner air flow from the north perhaps?

As to the models then yippee for the anomaly charts suggesting an upper pattern different from now byt about 4-5 days from now and for some time to come, see links below

NOAA

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

and EC-GFS

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

[Polar Maritime]

Looking forward to tomorrow with a cleaner air flow from the north perhaps?

 

Yes John, Stagnant Fog/drizzle here for days.. As you say hopefully some cleaner air tomorrow as some "slightly" fresher air pushes S/E.

 

Edited September 20, 2014 by Polar Maritime

[phil nw.]

Next week we see the modelled westerly pattern establishing but with a lot of high pressure close to the south it remains pretty dry for most of us away from the far north.

T84hrs fax

 

There will be quite stiff breeze at times as the lows to the far north move across tightening the isobars.

Still plenty of warmth heading for nw  Europe from the sub-tropical Atlantic but inevitably with the wind off the sea this will pick up the moisture and bring a lot of cloud across on many days with sunshine at a premium for someareas.

 

Thursday's GFS could be a typical picture.

 

with a bit of luck parts of the midlands and sheltered east and se districts could still see some bright interludes and in the warm air it would feel quite muggy with temperatures still into the low 20'C in the afternoons.

 

[Summer Sun]

For the majority of the UK low pressure has very little effect on us its only the far north which is prone to some rain and stronger winds at times

 

 

GFS ens shows above average 850's and very little rain for the foreseeable future

 

 

A bit more rain on the Aberdeen ens but even here we have no washout and again above average 850's

 

Edited September 20, 2014 by Summer Sun

[johnholmes]

Next week we see the modelled westerly pattern establishing but with a lot of high pressure close to the south it remains pretty dry for most of us away from the far north.

T84hrs fax

fax84s.gif

 

There will be quite stiff breeze at times as the lows to the far north move across tightening the isobars.

Still plenty of warmth heading for nw  Europe from the sub-tropical Atlantic but inevitably with the wind off the sea this will pick up the moisture and bring a lot of cloud across on many days with sunshine at a premium for someareas.

 

Thursday's GFS could be a typical picture.

1.png2.png

 

with a bit of luck parts of the midlands and sheltered east and se districts could still see some bright interludes and in the warm air it would feel quite muggy with temperatures still into the low 20'C in the afternoons.

 

 

yippee, bring on the westerly flow, it at least gives this area a chance of some sunshine.

I really am fed up with this murk,over a week of it on most days, apologies for the rant; my constructive  ideas are in the post at 0853 above.

Edited September 20, 2014 by johnholmes

[draztik]

To those currently enjoying this extension of summer, the ecm ensembles want to continue and extend the fine weather

Ecm ens days 10-15 height anom.

To those wanting a more seasonal outlook, best look towards mid October.

[shaky]

To those currently enjoying this extension of summer, the ecm ensembles want to continue and extend the fine weather

Ecm ens days 10-15 height anom.

To those wanting a more seasonal outlook, best look towards mid October.

its just seriously unreal to have such a settled spell in September and for that to continue on into october!!!come mid october you never know the high might still be on top of us!!

[Northern Sky]

its just seriously unreal to have such a settled spell in September and for that to continue on into october!!!come mid october you never know the high might still be on top of us!!

It might just be selective memory but isn't September often a fairly benign and settled month? Personally I'm quite happy to wait till the end of October for some wet, windy and then hopefully cold weather!

[phil nw.]

its just seriously unreal to have such a settled spell in September and for that to continue on into october!!!come mid october you never know the high might still be on top of us!!

 

 

To those currently enjoying this extension of summer, the ecm ensembles want to continue and extend the fine weather

Ecm ens days 10-15 height anom.

To those wanting a more seasonal outlook, best look towards mid October.

 

 

yippee, bring on the westerly flow, it at least gives this area a chance of some sunshine.

I really am fed up with this murk,over a week of it on most days, apologies for the rant; my constructive  ideas are in the post at 0853 above.

The ens from both main runs in no mood to break the blocking around W Europe  down either once established.

In addition  to the ECM mean above the GFS showing the same scenario at T240hrs.

 

and the ens graph extending the largely dry and settled outlook well into October as already suggested.

 

maybe only the far north seeing some noticeable rain on the odd day.

[damianslaw]

The models continue to play down any proper atlantic onslaught next week - with heights staying more robust close to the country and very reluctant to move on. All very much due to the positioning of the Jetstream, which is sticking well to the north, with little amplification in the flow, allowing heights to settle to the south and ridge into NW Europe. The end result a weak westerly flow, with cloudiest wettest and coolest conditions reserved for the NW - with the south and east holding on to quite a bit of fine dry bright pleasant weather.

 

Mmm on a personal note, I would like to see a more notable atlantic attack just to shake things up a little, its been an exceptionally quiet spell of weather for the time of year, we've had a month of settled weather now, not something you would normally associate with September - though 1/2 week settled spells are very common.

 

Longer term all eyes on how the Jetstream behaves - as always, it should begin to fire into action as we move into October thanks to steeper temp gradients developing over NW Atlantic.. but no signs at the moment of it digging southwards anytime soon.

 

This has been a most tedious period for model watching - I have to say it again - 'Wake me up when September ends'.

[knocker]

Just consulted the crystal ball and there doesn't appear to be any great thermal gradient as yet.

 

 

[Summer Sun]

UKMO shows high pressure rebuilding in next week for all but northern Scotland by the end of the week

 

Wednesday has north to north westerly winds so fresher than of late but dry for most with temps ranging from 15c to 19c, warmer by Friday as high pressure returns

 

 

850's rise by the end of the week t120 850's unavailable at the time of posting

 

Edited September 20, 2014 by Summer Sun

[Timmytour]

 

This has been a most tedious period for model watching - I have to say it again - 'Wake me up when September ends'.

I've experienced three terrific storms in the past 30 hours.....so watching the models might not be interesting but the weather is!  Maybe it's easier when it's settled but making weather forecasts from the model runs has been pretty good for the last 15 days. Just from reading interpretations on this forum I was telling mates 10 days ago to expect a spell of pretty decent weather followed by some thunderstorms coming into this weekend. So I'm looking good!! 

In truth I suspect the accuracy of the models is much the same as it always is, but the inaccuracies when it's high pressure generally dominating don't really lead to the dramatically different weather outcomes as when tracks of depressions are pushing around and across us

[IDO]

I think the pattern for the next 2 weeks has been established, with HP well in charge for most of the UK with the jet running somewhere to the North of the UK. The LP systems kept away from England and by D16 no sign of any change:

 

D10 GFS:   D16:  

 

Periods of +12c uppers mixed with average, and later in the run cooler uppers, as you would expect from a westerly flow.

 

GEM at D10 also hinting at a spell of warmer uppers as HP dominates:

 

 

 

UKMO at D6 also in line: 

 

GFS picked this signal, of higher pressure, ran with it and continues to trend for the Jet to push to the north, meaning few incursions of Atlantic lows. Any signal from GFS at the end of FI for the return of something less settled gets super-ceded quickly with the continuation of a forecast for the status quo. It looks a strong signal but as with weather you never know, however the rest of September looks settled.

 

 

 

[Cloud 10]

Quite a large disagreement between the GFS and the UKMO at just 96 hrs this evening,with the UKMO having much more amplification in the jetstream,although could be just a dodgy run?

 

gfs..  ukmo..