Model Output Discussion - 1st August 00z---------->

[knocker]

Saturday and early Sunday looking to be the dodgy time over the weekend as the wave depression crosses the UK moving NE

Edited August 26, 2015 by knocker

[Man With Beard]

Yes Knocker that front to the south is another forecasting conundrum - a front on the 564 dam line is bound to be lively too. As a result, this Saturday is too close to call in the south - will it be front to the south (in which case a pleasant day), front to the north (potentially hot), or front slap bang on top (humid but cloudy and possibly thundery). For northern areas, a decent start to the holiday weekend for most, with average temps.

 

Later in the Bank Holiday weekend, the waters gets muddier still. Three different takes on the Monday:

Nothing particularly settled - indeed, UKMO is very windy and wet up north - but ECM doesn't develop the low until Tuesday and holds onto the continental warmth a bit longer. In fact, Sunday could be hot in the SE according to the ECM:

The trade-off is that the HP in the Atlantic is less keen on moving in later in the week:

[ANYWEATHER]

Evening All. A very complicated outlook for the bank holiday weekend ,unsettled and bluming wet in some places. The low developing is still to be decided by the weekend .Who can call this one? The guy on Radio 4 tonight just before 6  said the weekend would follow the next couple of days!? Very misleading!      Out to T+120 The very Unreliable time frame A Ridge ,Yes a Ridge of High pressure dares to cross the country....

[knocker]

Pretty good agreement between the NOAA 6-10 and the GEFS 6-10 so at the moment indications are that the HP could move far enough east by the middle to the end of next week but even then it may be fairly brief tenure. Best just keep a watching brief for the time being and at the moment the fence looks quite inviting.

http://www.tropicaltidbits.com/

 

[knocker]

Still no agreement on the movement of the shallow low over Sunday and Monday between GFS and the METO although Monday is certainly looking to be okay and for parts of the country the whole weekend isn't looking too bad. And of course you won't be surprised to hear that the GFS has HP firmly back in the saddle for next week albeit with temps below average. At this range I'll stick with the fax charts.

http://www.tropicaltidbits.com/

Edited August 27, 2015 by knocker

[Summer Sun]

UKMO this morning shows mixed BH Monday with some showers possible during the opening days of September we have high pressure to the west maintaining a northerly flow so temps will be a bit down on the average and chilly over night with a risk of frosts in some rural parts

 

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON THURSDAY AUG 27TH 2015

 

THE CURRENT GENERAL SITUATION A trough of Low pressure will lie across Northern France today, clearing away to the SE tonight. A showery WSW flow will continue to affect all parts of the UK.

 

http://www.wetterzentrale.de/pics/Rtavn001.gif 

 

MODELS-2 WEEK HEADLINE Gradually becoming less unsettled with longer dry spells and some sunny spells next week.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast pattern shown this morning indicates a slow shift of the SW to NE  moving flow across the UK currently to move towards Europe while over and around the UK the flow becomes weak and ill defined for some considerable time from next week onward. Late in the run the flow realigns to a point well South of the UK allowing pressure to fall over and around the UK. 

 

http://www.netweather.tv/index.cgi?action=jetstream 

 

GFS OPERATIONAL The GFS Operational Run today shows rather changeable conditions over this weekend with some showers and rain around in slack synoptics. Then through next week and the rest of the run High pressure takes control over the UK. The High cell is shown to edge in only slowly giving several days of cool Northerly winds and jolly chilly nights but bright, sunny days. Then later in the period temperatures rise as the Northerly flow is cut off by the High cell settling over the UK. Very late in the period the High migrates to the NE allowing pressure to fall across the UK with some rain or showers returning to the South and SW in particular. 

 

http://www.wetterzentrale.de/pics/Rtavn1441.gif

 

http://www.wetterzentrale.de/pics/Rtavn3841.gif 

 

THE GFS CONTROL The GFS Control Run today is in many ways very similar in theme to it's operational companion this morning indicating a strong influence from High pressure affecting the UK through the period. Things start slowly as the cool North or NE flow for a while tempers any warmth and gives rise to some very cool nights and the odd shower in the East. Then through Week 2 the High settles across the UK with a warming trend in light winds with days of warm sunshine coupled with cool and perhaps increasingly misty nights. 

 

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning show a bias of approximately 65%/35% in favour of High pressure across or near the UK in 14 days time. 35% of the members show High pressure over the UK while another 30% show High pressure affecting the South most while the other 35% indicate varying degrees of influence from Atlantic Low pressure to the North or NW.

 

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

 

UKMO UKMO today shows the changeable Bank Holiday Weekend under shallow Low pressure  giving way to a large mid Atlantic High developing next week and on this run it keeps it well West of the UK out to next Wednesday maintaining the developed Northerly flow across the UK ensuring temperatures stay somewhat suppressed but being compensated by some dry and fine weather with just a few daytime showers towards the East and jolly chilly nights under any clear skies.

 

http://www.wetterzentrale.de/pics/Rukm1441.gif 

 

THE FAX CHARTS The Fax Charts this morning show a lot of slack pressure patterns over the UK come the weekend with a stubborn trough slow moving near the South on Sunday with rain at times here while the North and West see sunshine and showers in a SW breeze. Things remain rather showery looking on Bank Holiday Monday under Low pressure to the NW and an exiting Low to the East.

 

http://www.weathercharts.org/ukmomslp.htm#t120.

 

GEM GEM today also show slow improvements next week with slow being the buzz word. High pressure in the Atlantic with Low pressure over Northern Europe show Northerly winds and showers for quite a portion of next week slowly giving way to dry and fine weather next weekend as the High pressure to the West finally comes to rest across the UK.

 

http://www.wetterzentrale.de/pics/Rgem2401.gif 

 

NAVGEM NAVGEM also shows a similar theme to the rest with the painfully slow ingress of High pressure from the West tempering the cool Northerly flow down across the UK for the early and mid week days with the High pressure still lying West of Ireland next Thursday.

 

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

 

ECM ECM this morning is still showing strong indications of a pattern change next week with High pressure gradually becoming more influential across the UK, this felt most by those in the Summer long afflicted NW where dry and fine weather will predominate from early next week with dry, bright days and jolly cold nights. Improvements will be felt elsewhere too with the cool North or NE flow and the odd shower in the East during the week falling light by next weekend.

 

http://www.wetterzentrale.de/pics/Recm2401.gif

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last evening continues to endorse the prospect that the UK could lie close to or under High pressure in 10 days time

 

http://www.wetterzentrale.de/pics/Reem2401.gif 

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models have strengthened their theme towards High pressure based weather developing next week from off the Atlantic.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM. This morning's verification statistics show ECM leading the way at 3 days with 96.2 pts followed by UKMO at 96.0 pts and GFS at 94.9 pts. At 5 days UKMO is king at 87.1 pts followed by ECM at 86.3 and GFS at 83.3 pts. Then at 8 Days ECM still leads at 61.2 pts over GFS's 55.2 pts. Finally at Day 10 ECM leads GFS at 43.9 pts to 38.0 pts from GFS.

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png 

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig

 

MY THOUGHTS At last this morning I can report on the strong possibility of a pattern change in the weather across the UK most welcome of all for those living in the NW. We still have several more days to go on the current rather changeable theme of weather and although the Holiday Weekend looks far from a write off temperatures could be a bit better and the patchy rain and shower risk for most areas is an unwanted ingredient of the weekend forecast. Nevertheless, it could be worse as the  threat of UK wide wind and rain moving up from the SW on Sunday has receded somewhat so to affect more Southern areas only for a time. We then finally see pressure building out over the Atlantic next week at much higher latitudes than of late spawning some better weather for the UK. The down side of this in the short term is the persistence of a Northerly flow down across the UK for much of next week as Low pressure by then out over Northern Europe holds up the migration East of the Atlantic High into the UK. The resultant weather looks set fair next week for many with some sunshine by day with odd showers still flirting with Eastern areas in particular at times, also a chilly North wind will likely be blowing holding temperatures back at average levels but probably most notable of all will be some very cold nights for early September with frost a real possibility for many, certainly in the North and frost hollows elsewhere too. Then looking further ahead the High pressure should make landfall across Britain by next weekend which would cut off any cold Northerly feed with light and warming winds then especially by day but with the risk of mists and fogs by night. Any suggestion of a breakdown following this stage is at this range futile so I will not mention any methology on how this might occur on output shown today.

 

It really is nice to report on something positive for the UK in terms of better weather for all of the UK as a whole and not just the SE and I'm sure the NW will salivate over the real prospect of a sustained dry spell commencing next week after recent months monotony. While improvements in the SE will be less notable under the Northerly flow expected next week it's nice to see High pressure largely dictating the weather events here too rather than Low pressure up to the NW or SW. Lets hope I haven't given my predictions the kiss of death in my positivity this morning but I do feel for once that with such a lot of cross model support for High pressure to become dominant from the West next week we can say with reasonable confidence that a marked improvement is on the way even if it's not on this occasion in the shape of a late season heatwave. 

 

Next update from 09:00 Friday Aug 28th 2015

[knocker]

With HP moving in around Weds the anomalies have the ridging closer to home by Sunday with the trough Scandinavia to Europe. Thus pushing the HP a tad further east. Hopefully a few days of settled for everyone even if temps a little below average.

http://www.tropicaltidbits.com/

Edited August 27, 2015 by knocker

[Summer Sun]

This mornings ECM ens shows the high very slowly moving over the UK during next week, don't expect any high temps though to start with as it will have a northerly flow whilst still pleasant enough in any sunshine and shelter nights will be rather chilly with a risk of grass frosts in sheltered rural areas. Towards the end of next week the high, then moves a bit further east cutting off the northerly flow so temperatures should start and rise a bit but the nights remaining chilly

 

Edited August 27, 2015 by Summer Sun

[knocker]

To emphasise how much uncertainty there is at the moment regarding TS Erica the GFS at 06 has it here and it doesn't show at all on the 00 ecm.

Chart weatherbell

Edited August 27, 2015 by knocker

[Frosty.]

The Ecm 12z shows a gradual improvement next week as high pressure centred to the west of the uk slowly drifts east, early next week brings sunshine and showers and windy for a time in the far NE but by midweek onwards it becomes more settled from the west with winds becoming lighter. Nights look like being cold for the time of year with a chance of slight frosts in rural northern areas and overnight mist/fog patches are likely to increase but by day there should be good spells of sunshine and feeling pleasant in the sun. There is very good support for pressure to rise through early September from the Gfs 12z too, and the met office so it's looking like a decent spell of early Autumn weather is on the way.

[ANYWEATHER]

Evening All, a mish mash of weather for the Bank Holiday weekend , and as the Schools go back after a rather dismal summer for many ,a big fat high pressure system appears next week which seems a default pattern for September.  Unfortunately the high pressure is in the wrong place ,dragging rather chilly and cloudy conditions with perhaps some drizzly rain at T+168hrs across the nation. Of course at this time frame its very unreliable , but the south coast of England and  South Wales will be the best place to be...at this time frame....

[legritter]

not many of us weather fans about tonight ,but nice to see some input from some .

All ifs and buts for bank holiday weekend but some places will get a soaking and others fair pretty well .

looking at todays charts and all other outlook data it looks like high pressure will be on the scene come autumn ! its been a fair summer here and all my crops have done well ,also worth mentioning that storms and hurricanes if and when they form could knock many long range forecasting Models ,Meteorology is full of surprises gang ,i look forward to our increasingly approaching autumn and winter ,cheers all .

[knocker]

Nothing to add to forthcoming UK weather at the moment so a quick look at the many uncertainties vis TS Erika. This GFS this evening has it running up the Florida coast with pretty impressive rainfall footprint although this will no doubt shift.

Chart weatherbell

Edited August 27, 2015 by knocker

[ANYWEATHER]

Nothing to add to forthcoming UK weather at the moment so a quick look at the many uncertainties vis TS Erika. This GFS this evening has it running up the Florida coast with pretty impressive rainfall footprint although this will no doubt shift.

Chart weatherbell

Could you please put this in the American thread

[knocker]

Could you please put this in the American thread

 

Why is model output discussion limited to the UK? And the post above mine includes a farming report and mention of hurricanes upsetting the models.

 

But feel free to delete if you feel inappropriate.

Edited August 27, 2015 by knocker

[fine wine]

Interesting post knockereview as this is very likely to increase the uncertainty with our model outlook.

[damianslaw]

Models showing a rare feature in months - the return of high pressure, something we have seen little of all year it has to be said, bar a period in April, and the odd couple of days of weak heights/ridge development over the country. It does seem a common theme for early September in particular - indeed almost becoming a norm.. I am going to start a separate thread on this.

 

A cool start to September on the cards notably so for some with some significantly below average minimum, frost very likely in the north.

[knocker]

Interesting post knockereview as this is very likely to increase the uncertainty with our model outlook.

 

Who knows really. At the moment there is still much uncertainty regarding the track and intensity of Erika it's a matter of keeping a watching brief. If it does loop NE into the Atlantic then yes it has the potential to upset the models.

[Scorcher]

 

A cool start to September on the cards notably so for some with some significantly below average minimum, frost very likely in the north.

 

 

 

For a time yes, but if the ECM is to be believed tonight, the high would slowly drift east- in fact it's very likely to do so, and therefore the northerly/NW flow will be cut off with a gradual rise in temperatures. 

[Frosty.]

The Ecm 12z ensemble mean gradually becomes anticyclonic. I think we are in for a very nice spell of early Autumn weather in the not too distant future with Atlantic high pressure slowly ridging eastwards during next week. Early next week looks like sunshine and showers and a chilly Nly flow but that gets cut off from the west as the high out west edges east. So becoming dry with increasing amounts of sunshine and lighter winds by the second half of next week but with cold nights where skies clear, cold enough for ground frosts / slight air frosts in rural northern areas and more in the way of overnight mist/fog once the high becomes centred over the top of the UK...really good early Autumn spell is firming up.

[Eugene]

For a time yes, but if the ECM is to be believed tonight, the high would slowly drift east- in fact it's very likely to do so, and therefore the northerly/NW flow will be cut off with a gradual rise in temperatures. 

 

But with it being September and it's a cool high not a Scorcher.

[Geordiesnow]

The set up next week is one of those where you may see some runs trying to edge that high in and others don't but the main trend does seem to be strongly in favor of the high staying out West with a cool Northerly flow coming down for a few days at least. 

 

Cloud amounts could be difficult to forecast, there is a bit of Polar Maritime air mixed in which may bring a more brighter outlook but the sun is still strong enough to bubble the clouds up and flatten out mid morning and this set up does seem to have that written all over it. Best of any breaks you would imagine to be sheltered areas and the further South and West you are but even then, at this stage, its hard to say just how much cloud there will be and of course that will determine how cool the temps will go at night. 

[knocker]

A Quick look at the latest EC32

 

The high pressure next week slides slowly SE as a trough builds mid Atlantic bringing the UK into a more SW flow and thus temps nearer average or slightly above by Monday 7^th.

 

During the week the trough positions itself to the NW of the UK (sound familiar) and likewise the Azores HP reasserts itself to the SW returning the UK to a very familiar westerly flow by the weekend of the 13^th with the N/S split. Temps average.

 

Keeping in mind this is very much broad brush the outlook from here to the end of September is along the same lines although there are signs that the Azores to the SW being the dominant partner as the trough to the NW is quite weak and gives no indication of spreading its wings too far south. ( but I think we have all been down this path before). Anyway given that the temps will be about average.

 

Summary.

 

Dry cool weather to around the 7^th  then becoming unsettled for a week, more particularly in the north, before becoming more settled again. Remaining quite dry especially in the south.

[chionomaniac]

If the GFS produced the 0Z run in the heart of winter I think a few on here would be wetting their pants. Lovely classic build of a cold high over the country followed by slow retrogression and ending in an attempted undercut.