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

[cheese]

It does look like August will continue the rairly reasonable conditions that we have experienced so far. Nothing really to spark any excitement but increasingly warm winds from the SW then S should ensure a summery feeling week. Low pressure does look like coming closer next weekend but winds likely to remain from a fairly warm direction.

Agreed - it looks particularly good for us east of the Pennines, as you say, continuing the theme of a very reasonable August in this part of the world. I see 25-27C here by the end of next week for the 22nd-26th period. Hope this output continues! August will certainly end up as the best month of the summer if this comes to fruition (but admittedly nothing exceptional for the time of year).

 

 

^^ chart is for the 23rd btw.

Edited August 16, 2015 by cheese

[Man With Beard]

Well blow me down with a feather... for all the life of me yesterday I thought we were heading back to the NW trough, all the ens seemed to want it ... but look at this tonight, the GFS, UKMO and ECM ops all foresee enough clout in a SEly jet to get troughing all the way to Iberia and force some sort of break-off low to our south. As they are all in, I'm guessing there's some mileage in it. Very hard to say what the result would be - GFS is absolute best case scenario for temperatures with 30C being threatened between D7 and D10 - equally could end more similar to last week. But the main winners would be Scotland. Last night was looking like an early autumn, but tonight's ops throw out hope of the best spell of the entire summer, starting from D6

[Singularity]

Continuing to focus on next weekend, what with the Bournemouth Airshow taking place as well as the Beaulieu Super Car Showdown.

 

It has been strange seeing GFS consistently output solutions which have the jet stream diving further south, more of a divide of low heights between the Atlantic and Europe and a stronger Scandi High than the other models have been coming up with.

 

By this I mean that GFS has always seemed the most reluctant to go that way in times past -but you know what, I can't recall much of a Scandi High and dividing low heights situation since the model was upgraded in late January (or was it February?) this year, so perhaps that did a number on its old foibles - or has it caused the model to be overly keen now?

 

Up to this morning, I was beginning to suspect that was the case, what with ECM having gone off the idea again despite giving it good consideration the previous evening.

 

Yet now we have UKMO dropping a major hint that we could see the cut-off low develop after all, though the t+144 chart doesn't suggest such an effective 'undercut' of the Scandi High as GFS has managed this evening.

 

What a run that GFS 12z operational is - with the stage set by t+144 (see above), temperatures climb into the high 20's quite widely for England and Wales next weekend, and then some spots climbing up to 30*C or so to start next week. Madness? Fantasy? Or a realistic way forward?

 

 

Well guess what, ECM's gone and flipped again. The cut-off low develops a day later, but it's very much there for all to see by Sunday, and ends up moving too close for comfort by Monday (unless it was to deliver in terms of thunderstorms):

 

 

 

It's worth taking note that the later development of the low means warm air doesn't push back NW against the cooler Atlantic air until Monday. It could be warm in the SE corner through the weekend (maybe 25*C if the skies are clear enough) but otherwise a nearer average situation I reckon, and on the cool side for the NW.

 

The good thing is, UKMO now has the Atlantic trough as far west as GFS for Friday, disagreeing with the ECM 12z operational, which raises the likelihood that the NW will instead escape the Atlantic flow next weekend, along with the chances of seeing that warm air hold on through the weekend for a wider portion of the UK - or even push further NW if we go the way of GFS.

 

 

There's still too many days to go before the weekend can be called one way or the other, but I'm feeling more hopeful after this evening's 12z operational runs 

 

I'll leave you with this - ECM agreeing with GFS in showing the Scandi High pushing further west by the middle of next week rather than getting shoved away east. Complete with the usual over-dramatised storm system in the Atlantic  :

 

[Frosty.]

I couldn't resist commenting on the Gfs 12z because it's the kind of run which shows perfect uk summer weather with the jet stream shunted north to where it needs to be to allow superb summery weather to all the uk. It's a great run from the end of the week ahead until almost the end of August with largely fine, sunny and very warm / hot conditions and just isolated heavy thundery showers, this would be a fantastic finale to this summer and I hope it happens because northern UK would finally have something good to remember from the last three months.

Edited August 16, 2015 by Frosty.

[Methuselah]

I admire your optimism, Frosty, really I do. But so far this summer, those charts have only materialized on about 3 days! Are you quite sure you are not 'flogging a dead horse'?

[049balt]

I admire your optimism, Frosty, really I do. But so far this summer, those charts have only materialized on about 3 days! Are you quite sure you are not 'flogging a dead horse'?

Frosty post what he sees, he is not the only one that is optimistic!

 

http://wxmaps.org/pix/prec4.html

 

Final week dry and warm.

Edited August 16, 2015 by 049balt

[Methuselah]

Frosty post what he sees, he is not the only one that is optimistic!

 

http://wxmaps.org/pix/prec4.html

 

Final week dry and warm.

I know he does, and I have no problem with it at all...If there's a good chart, anywhere to be found, Frosty will find it. Thank God for that!

[Frosty.]

Frosty post what he sees, he is not the only one that is optimistic!

http://wxmaps.org/pix/prec4.html

Final week dry and warm.

Cheers for that, I was recently accused of having a rose tinted view of the models but in a nasty and sarcastic way unlike Pete's comment which is good natured...Cheers Pete. I just call it as i see it, I never describe something that isn't there and for what it's worth, I think the gfs 12z has a good chance. We are now into the last few weeks of summer and I hope the north has a good spell within that time since they have had a terrible summer and then my thoughts are turning to what winter could bring with the added El Nino factor, after a few very poor winters I hope it's time for winter to deliver for all UK snow lovers. Edited August 16, 2015 by Frosty.

[Methuselah]

Cheers for that, I was recently accused of having a rose tinted view of the models but I just call it as i see it, I never describe something that isn't there and for what it's worth, I think the gfs 12z has a good chance. We are now into the last few weeks of summer and I hope the north has a good spell within that time and then my thoughts are turning to what winter could bring with the added El Nino factor, after a few very poor winters I hope it's time for winter to deliver for all UK snow lovers.

You, rose-tinted glasses? Never!

[I remember Atlantic 252]

I know he does, and I have no problem with it at all...If there's a good chart, anywhere to be found, Frosty will find it. Thank God for that!

 

Yes, Frosty, always look out for, summer and winter, his posts always good

[Frosty.]

You, rose-tinted glasses? Never!

Yes Pete, we can all have a good laugh, I enjoy reading your posts, anyway, the last week or so of the meteorological summer shows signs of bringing a lot of warm or indeed very warm and fine weather to at least the south of the uk. It could be a marked nw/se split as the met office keep saying or it could be more like the gfs 12z shows with good weather extending further n/nw at times.

P.S...Cheers for your kind comment ilovethesnow

Edited August 16, 2015 by Frosty.

[johnholmes]

Hard to call for next weekend I feel. The positions of the trough and ridge, both at 500mb and the surface are obviously crucial to what temperature levels for any part of the country and how settled or unsettled any part is.

The 500mb anomaly charts can not give the detail required to get specific ideas for the coming weekend. The trend, using them, to me suggests the ridge being more dominant later in this coming week before the trough reasserts itself over the weekend. Now just how that timing will pan out is for the synoptic models during the coming days to firm up on. As someone commented the 12Z charts from GFS are rather different from those of yesterday. A good summation of what is likely to happen for 2 or 3 days. Changing in emphasis as the models try to work out just what will occur Saturday and Sunday.

An interesting few days as we watch and wait.

Edited August 16, 2015 by johnholmes

[knocker]

A quick look at this morning's GFS for the next week.

 

Tuesday has a depression forming mid Atlantic running ENE with it situated NW of N. Ireland by 12z Wednesday. It the turns north and the associated fronts and rain band ingress the western half of the UK but lose momentum and dissipate over central UK by Thursday. This leaves a large depression south of Iceland by 12z Friday with the UK in a south westerly air stream apart from the far SE which is in a southerly drift allowing temps of around 25C.

 

On Saturday things become a little complicated. The quite strong jet turns south around the upper trough to the west of the UK and then north around it's eastern flank over Ireland as it's squeezed between an upper ridge over the North Sea. On the surface this introduces a southerly flow over the UK with temps tending above average particularly in the east where temps could reach 28C.

 

By 12z Sunday low pressure over Spain has moved into France bringing a SE airflow and above average temps particularly in the eastern half of England where they could once again reach around 27C.

 

This low swans around N. France/Germany for the next two or three days and in conjunction with the HP to the NE continues the theme of very positive temp anomalies over the UK particularly in the east.

 

This analysis is very finely balanced and it will be no surprise if the ECM has a different take on it. The upper trough only has to be a tad further east and it's a different ball game so don't BANK.

 

Chart weatherbell and http://www.tropicaltidbits.com/

Edited August 17, 2015 by knocker

[mushymanrob]

Hard to call for next weekend I feel. The positions of the trough and ridge, both at 500mb and the surface are obviously crucial to what temperature levels for any part of the country and how settled or unsettled any part is.

The 500mb anomaly charts can not give the detail required to get specific ideas for the coming weekend. The trend, using them, to me suggests the ridge being more dominant later in this coming week before the trough reasserts itself over the weekend. Now just how that timing will pan out is for the synoptic models during the coming days to firm up on. As someone commented the 12Z charts from GFS are rather different from those of yesterday. A good summation of what is likely to happen for 2 or 3 days. Changing in emphasis as the models try to work out just what will occur Saturday and Sunday.

An interesting few days as we watch and wait.

 

interesting, i thought the opposite! but maybe im letting the current ops skew my interpretation as they seem to suggest the atlantic trough influencing us more later this week before that energy disipates and the euro high becomes more dominant.

time will tell i guess

[BlueHedgehog074]

Although the models are playing with various scenarios regarding the stand off between Atlantic troughing and High Pressure over Scandinavia towards the weekend and into next week - some breaking Low Pressure further East (00Z ECMWF - not for whole run, mind), some where Lows from the Atlantic trough are forced to slide South-East to the South of the UK (0Z GFS) - I feel the below, at the moment, is still relevant.

[knocker]

The GEFS anomaly is not fully supporting the ops and the ECM ops does push the tough a tad further east.

http://www.tropicaltidbits.com/

 

 

[Frosty.]

The Ecm 00z shows the weather becoming warmer and more humid across the s/se of the UK during the second half of this week with the best of the weather across the southeast corner bar the odd shower and temps gradually rising into the mid / upper 20's celsius for fri/sat/sun whereas further north and west become more unsettled and breezier with rain and showers but still with some sunshine at times and reasonable temperatures in a swly/sly airflow. Further ahead becoming less warm / fresher for a time from the west but by T+240 hours we are poised (or at least the south is) for a surge of very warm / hot continental conditions to spread northwards beyond day 10 with a trough becoming slow moving to the west of the UK.

Edited August 17, 2015 by Frosty.

[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 MONDAY AUG 17TH 2015.

 

THE CURRENT GENERAL SITUATION. An area of slack winds will continue to affect all of the UK for the next 24-48hrs. A frontal trough will extend NW across the North Sea later today and tomorrow..

 

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

 

MODELS-2 WEEK HEADLINE Remaining somewhat mixed with a lot of dry weather for all but with occasional rain too at times.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the main arm of the flow moving SE over the Atlantic to the Pyrenees with a returning arm North over the North Sea. The Spanish end of the flow breaks up soon while the flow is steered more NE over Scotland as the process of developing a sharp trough in the flow just to the West of the UK is shown late this week and through Week 2. Thereafter, the forecast becomes complex with the flow appearing to break up and become light around the UK in a general broad trough across the Atlantic.

 

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

 

GFS OPERATIONAL The GFS Operational Run today shows High pressure to the NE. through this week a Low pressure will become dominant up to the NW of the UK pushing troughs occasionally NE over the UK. These will be weak in the SE where warm and muggy air will reign for most of the week whereas elsewhere thicker cloud and rain at times is mor probable. then in Week 2 pressure falls to the South as a thundery low affects the South and SE before all areas become cooler and more unsettled later next week as Low pressure cebtres across the UK before shifting to the East at the end of the run with cool Northerlies for all.

 

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

 

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

 

THE GFS CONTROL The GFS Control Run today shows the Low developing to the NW remaining the dominating feature across the UK for the following week before pressure builds from Europe to lead most areas into a fine, warm and unsettled period before the High relaxes to the NE and allows Low pressure to begin to affect the UK, first in the SW then elsewhere towards the end of the period. 

 

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning show a good strong trend towards High pressure being dominant around or over the UK in 14 days with fine and settled weather for all with the members that show something more unsettled only catering for this to affect the far North and NW of the UK.

 

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 Low pressure from mid Atlantic gradually becoming influential across the UK from midweek. The North and West will see most effects from this with rain and showers while effects for the South and East will be more minimal with High pressure closer by to the South and SE but by Day 6 a more vigorous Low is shown South-west of Ireland destined for the UK to start next week.

 

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

 

THE FAX CHARTS The Fax Charts this morning show ta gang of weakening troughs moving West to east across the UK later in the week with some rain for most at some point or another. The airflow looks moist and humid until the clearance of a cold front East at the weekend brings fresher air across from the West.

 

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

 

GEM GEM today maintains the theme of Low pressure to the NW and higher pressure to the SE for most if not all of the 10 day period it covers this morning. While some rain at times is shown for the North and West throughout far less is likely to reach the SE in warm SW winds before a general trend towards all areas coming under more direct effect from Low pressure later as it moves closer in to the West and NW of Britain.

 

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

 

NAVGEM NAVGEM too shows Low pressure to the NW becoming the dominant role model later this week with some rain at times especially towards the North and West while the South and East see a lot of dry, warm and hmid air within a lot of cloud. Later the Low slips down across the UK giving all areas an equal risk of rain and showers in more average temperatures by then.

 

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

 

ECM ECM this morning shows very changeable synoptics day to day revlving around a complex area of Low pressure over the North Atlantic and later over and around the UK. The North and West will see rain at times from midweek, spreading further East later to give the UK an unsettled and showery interlude next weekend and early next week before a new Low to the west scoops up more warmth and humidity late next week with heavy rain possible in the West at least.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last evening shows Low pressure West of Scotland with SW winds across the UK. the most likely weather would be a traditional NW/SE split in the weather with rain at times to the North and West while the SE sees the longest dry and warm periods.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models are trending towards another more unsettled interlude later this week with the longer term models from GFS hinting at High pressure again in Week 2, still supported by it's ensembles.

 

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 95.7 pts followed by UKMO at 95.4 pts and GFS at 94.6pts. At 5 days ECM is stll king at 85.7 pts followed by UKMO at 84.9 and GFS at 82.9 pts. Then at 8 Days ECM still leads at 59.6 pts over GFS's 55.0 pts. Finally at Day 10 ECM leads GFS at 40.7 pts to 36.1 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 Most output this morning show something for everyone as all output suggests quite a changeable pattern across the UK over the next few weeks. We start fairly benign as the UK lies in nomansland between both High and Low pressure systems but the pattern simplifies later this week as Low pressure, supported by all models settling to the NW of the UK. Fronts will then be fed East across most parts with mild and muggy air making for a lot of cloud at times and not much in the way of sunshine plus of course some rain, heaviest and most persistent in the North and West. Then most output seems to want to lower pressure further across the UK with all areas coming under a risk of rain or showers at times into next week. Then looking longer term there is a theme that suggests a build of pressure from Europe from GFS later next week bringing the UK under fine and warmer conditions with some summery sunshine should it evolve, though it doesn't look like lasting long. At 10 days ECM doesn't really want to play ball with rising pressure with Low pressure quite close to Western Ireland with unstable if warm Southerly airflow over the UK. It's 10 Day mean chart though not relaeased at the time of compiling this report looks unlikely to look much different to last night's I would think. So looking through the maze there is no consolidation between the models of note this morning with the notable fact for me being that Northern hemispheric patterns across the two weeks failing to lower pressure enough in the Greenland area to allow Low pressure areas to pass far enough to the North and NW to miss the UK given also that the Jet stream though weak at times continues to lie too far South. As a result some rain at least is likely for all at times and while the SE may hold on to a lot of dry weather for longest even here looks like seeing some rain eventually with still no hard concrete evidence of cross model support for anything particularly long lasting with regard to High pressure and summer warmth on a UK wide basis as we head towards the end of the meteorological Summer months.  

 

Next update from 09:00 Tuesday Aug 18th 2015

[Frosty.]

An all too familiar story Frosty"..

If Summer Was A Movie ? ..............................

image.jpg

That's a great movie, really hope you guys in Scotland have some of what the gfs 00z shows next week with widespread warmth and sunshine and just isolated heavy and thundery showers, mainly down the spine of the UK. We have entered the last chance saloon as far as summery weather in northern Britain for august is concerned but I think next week you could see a long overdue change to warmer weather with the jet stream pushed north of the uk.

Edited August 17, 2015 by Frosty.

[Nouska]

The GEFS anomaly is not fully supporting the ops and the ECM ops does push the tough a tad further east.

http://www.tropicaltidbits.com/

 

I suppose this will be like two weekends ago and be extremely difficult to get positioning right till nearer time. That's a fierce swipe of polar air being introduced into the summer atmosphere.

 

 

Reading EPS from ECM not nearly as warm as the GFS but scope from members to see warmer.

 

http://i.imgur.com/HneslMr.png

[Napplewh]

At least we should all enjoy Summer sunshine this weekend! according to GFS!

Interesting - GFS00 Predicts low pressure but GFS 06Z predicts high pressure! 

[knocker]

I suppose this will be like two weekends ago and be extremely difficult to get positioning right till nearer time. That's a fierce swipe of polar air being introduced into the summer atmosphere.

 

 

Reading EPS from ECM not nearly as warm as the GFS but scope from members to see warmer.

 

http://i.imgur.com/HneslMr.png

 

Not dissimilar to the 06 GEFS. I can't help feeling it's edging away from the quite warm scenario. Maybe a bit premature to say that though.

 

http://www.tropicaltidbits.com/

[stodge]

Afternoon all

 

The 12Z rolling out at present but the 06Z a classic JTC (Jam Tomorrow Charts) with plenty of settled HP-dominated weather in low-res but the immediate future much more uncertain and unsettled:

 

 http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

 

Probably not of huge relevance at the moment but the ongoing split between HP to the NE and SW and LP to the NW and SE leaves Britain in the classic COL or No Man's Land. 

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015081700/ECM1-144.GIF?17-12

 

This morning's ECM for next weekend reflects both the negative NAO with the trough dropping well to the south and the very light winds associated with the Col. 

 

http://modeles.meteociel.fr/modeles/gem/runs/2015081700/gem-0-150.png?00

 

GEM not very far away from that either.

 

http://www.meteociel.fr/ukmo/runs/2015081700/UW144-21.GIF?17-06

 

UKMO more extreme if anything with the centre of the LP well south.

 

The GFS 06Z provides a way out which would be wholly favourable by providing some energy off the eastern seaboard which pushes the Azores HP NE to merge with the Scandinavian HP and set up shop over the UK. Given we are at the time of year when tropical systems get involved it's not a wholly improbable scenario and may be one reason we often get decent September and October spells - I wonder if there is a correlation between the path of active tropical features and the recurrence of HP around north and north-west Europe.

[Milhouse]

It looks like eastern parts wont escape the rain tomorrow, contrary to earlier predictions. Looks a pretty drab day here with SW England best placed for any dry and bright weather. From Wednesday onwards its back to a traditional NW/SE split and becoming rather warm again in the SE.

 

[Eugene]

As expected any HP settling things down has been pushed away by a strengthening atlantic moving in, looks wet and windy next sunday/monday on UKMO/GFS 12Z.