Model Output Discussion - 3rd May Onwards 00z--->

[knocker]

It still doesn't appear to me that there is any great certainty how the trough/ridge scenario is going to play out looking at this morning's anomalies. Having said the I still reckon the influence of the HP over the UK to be favourite.

Charts weatherbell

 

[Thundery wintry showers]

Looking over the outputs and the NOAA 6-10 and 8-14 day anomalies, I am getting a general message that high pressure will increasingly tend to be close by to the west and south-west as we head towards June, though with northern and eastern Britain prone to little disturbances running around the periphery of the high.  I am being reminded of what happened in June 2013, with a general SW-NE split, the SW dry and sunny with some cool nights more than offset by warm days, but northern and eastern Scotland and eastern England more prone to cooler and cloudier (though still generally drier) than average conditions.  I expect the generally sunnier than average conditions and above-average daytime maxima to extend up the western side of Britain as far as south-west Scotland, but south Wales and south-west England are likely to be favoured the most consistently.

 

This is the 8-14 day outlook from NOAA which still suggests an Azores High ridging further north than usual, promoting generally north-westerly winds over the British Isles:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814day.03.gif

 

The general tendency is for cooler cloudier conditions with scattered light showers to be more frequent during the last week of May than during the first week of June, when we will probably see the high pressure ridging further east at times.

Edited May 17, 2015 by Thundery wintry showers

[Summer Sun]

UKMO again shows high pressure becoming more influential for the latter part of the week and into the BH weekend, where you have the sunshine temperatures will respond very well with the high teens maybe even low 20's possible, further north in Scotland the risk of rain / showers remains especially at first it will also be breezier here as your closer to the low

 

[I remember Atlantic 252]

UKMO again shows high pressure becoming more influential for the latter part of the week and into the BH weekend, where you have the sunshine temperatures will respond very well with the high teens maybe even low 20's possible, further north in Scotland the risk of rain / showers remains especially at first it will also be breezier here as your closer to the low

 

 

about time too, anyway where's Frosty? not seen him on here for a bit

[stodge]

Evening all

 

The NAO running weakly positive at present:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao_index.html

 

A lot of scatter toward the end of the month so no real guide there:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/new.nao_index_ensm.html

 

The AO, having returned moderately positive, looks set to dive back towards negative values at month end:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

 

This would be an indicative chart albeit a very long way off:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015051712/gfsnh-0-348.png?12

 

With reasonable heights over the Pole and the Atlantic HP in its normal summer position, the index is negative but not strongly so as it would be if lower heights existed at lower latitudes. Thus, nothing happens too quickly and nothing too extreme happens. The HP isn't in a useful position for warmth for the British Isles but nor is there anything approaching a rain fest. The synoptics keep the southern heat at bay and allow a N or NW'ly drift so it's a chart with nothing for everyone.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015051712/gfsnh-0-384.png?12

 

Worse if anything for fans of heat with the trough migrating westward to be just north of the UK and pulling in a cool (though not overly so) airflow. The heights are over the Pole and extending SW through eastern Greenland to the mid-Atlantic HP. You'd have to say not a brilliant set up for warmth for NW Europe or indeed western Europe as a whole with cooler air even into Iberia.

[knocker]

Interesting GEFS anomalies this evening and I'm not sure you would plonk a lot of money on them verifying.

 

Still going with HP influence for the 23rd (just) before rapidly bringing the trough back into play again until the 28th before reverting to HP for the rest of the run. So perhaps a good start to the BH but slipping downhill thereafter except for Cornwall. And this NE/SW split continuing for the first half of the week. It's all very knife edgy to lapse into meteorological speak.

[legritter]

Evening gang ,i,v just had a look at the charts and Data [the first time in a while as other things are keeping me busy ] and i can only say No big heatwave yet ,but no washout so lets just hope that eventually high pressure will drift in closer to our shores .

I think i can sum up current synoptics ,its been good out in the garden today but our gas fire as just gone on ,but as an older poster with cold legs its comfort ,take care all   i,ll have a half .

[Frosty.]

about time too, anyway where's Frosty? not seen him on here for a bit

Just got back at the right time, this evenings Ecm 12z is very encouraging from Thursday onwards with pressure rising as the Azores high ridges towards and into the UK, it looks particularly good for the southern half of the BI with an increasingly settled outlook and temperatures rising too, it looks like a marked improvement is on the way beyond midweek.

[ANYWEATHER]

Cool and changeable sums it up from both ecm and gfs at T+168 ,Both models holding hands for a changeable outlook and rather chilly

[Frosty.]

Cool and changeable sums it up from both ecm and gfs at T+168 ,Both models holding hands for a changeable outlook and rather chilly

The Ecm 12z shows a transition from cool and changeable with sunshine and showers during the first half of the week to gradually more settled with pressure rising and eventually becoming warm, especially further south. I think there are definite signs of recovery with much nicer weather on the way through late May and into June.

Edited May 17, 2015 by Frosty.

[Summer Sun]

Cool and changeable sums it up from both ecm and gfs at T+168 ,Both models holding hands for a changeable outlook and rather chilly

 

However the day before and after those charts looks very pleasant for some with temperatures not far off 20c

 

 

Granted some areas struggle with temperatures suppressed but many central, southern and eastern areas see temperatures a lot higher than of late

[049balt]

Cool and changeable sums it up from both ecm and gfs at T+168 ,Both models holding hands for a changeable outlook and rather chilly

Mostly dry with normal temps. would be a bit more accurate.

[Frosty.]

Mostly dry with normal temps. would be a bit more accurate.

Agreed, I think it's misleading to say the weather will continue to be cool and changeable, the second half of the week looks drier than the first half, and eventually it looks like it could become rather warm in the south.

[DAVID SNOW]

Mostly dry with normal temps. would be a bit more accurate.

 

Sorry but AW is  correct, rather low mins rising to maybe 16 degrees (in the south)  is on the chilly side for the time of year.

[Frosty.]

Sorry but AW is  correct, rather low mins rising to maybe 16 degrees (in the south)  is on the chilly side for the time of year.

16 degrees celsius is around the average maximum temp for England in mid to late May, not chilly for the time of year at all, and in any sunny spells, pleasantly warm.

[bluearmy]

Looking like a n/s split as far as settled/less settled goes. certainly headed in a generally promising direction as things stand.

[johnholmes]

It constantly amazes me how different folk look at the same output from the same models and get rather different conclusions.

ECMWF and GFS look fairly similar at 144h on the 12z outputs, so perhaps we can take the 18z temperature chart from GFS to illustrate what it is predicting, see 12z today (Sunday)

http://www.wetterzentrale.de/topkarten/fsavneur.html

roughly 10-17C far north to far south.

So what are maximum temperatures normally for May?

Looking at Met O data suggests

12.7C for the far north of Scotland to 15.3C for somewhere like Weymouth.

Touch  belwo in the far north to touch above in the far south IF the model is correct.

[mushymanrob]

Noaa anomaly charts still wont support the ecms pressure rise over us, but still insists on an upper trough near/over the uk maintaining the cool unsettled conditions.

Id be suprised and happy for the ecm to be on to something... But..

[johnholmes]

Noaa anomaly charts still wont support the ecms pressure rise over us, but still insists on an upper trough near/over the uk maintaining the cool unsettled conditions.

Id be suprised and happy for the ecm to be on to something... But..

 

and the actual chart for 6-10 below.

To me it does support the idea that the anomaly charts are trending away from the trough dominated flow north of west to a more westerly type with +ve heights edging nearer the UK. It is only the first day that all 3 have suggested this trend but it does look a feasible one to me. So after a coolish and rather changeable few days then prospects of it starting to settle down a touch from the WSW?

Of course my summary of the anomaly charts might be wrong, indeed they might be wrong but that is how it looks to me this evening.

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

[cheese]

Sorry but AW is  correct, rather low mins rising to maybe 16 degrees (in the south)  is on the chilly side for the time of year.

Average maximum temperature for Leeds in the last week of May is 18C and I believe 20C for London so yes, 16C is below average, and quite cool for nearly June.

[knocker]

Just been looking at the ECM and take the anomaly at T212. It still has the trough influencing the NW but running it through the extended period gradual weakening of the trough and a weasterly flow between the two HP areas. Average temps.

Chart weatherbell

Edited May 17, 2015 by knocker

[Milhouse]

Well the change to a more settled and warmer period is still set to commence around midweek, despite protestations from some that the outlook is cool and changeable. If the current charts were to verify I can see the mid to high teens being reached during the BH weekend with the odd 20c in the south, so around average as others have said. We have seen 15-17c reached in a number of spots yesterday in upper temps of around 0c.

[summer blizzard]

and the actual chart for 6-10 below.

To me it does support the idea that the anomaly charts are trending away from the trough dominated flow north of west to a more westerly type with +ve heights edging nearer the UK. It is only the first day that all 3 have suggested this trend but it does look a feasible one to me. So after a coolish and rather changeable few days then prospects of it starting to settle down a touch from the WSW?

Of course my summary of the anomaly charts might be wrong, indeed they might be wrong but that is how it looks to me this evening.

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

 

Looking at the wider pattern, that's the first proper removal of the south west US trough. I'd suggest that while week 2 probably sees a N-S split (i imagine low pressure will be a tad more influential than current models suggest in the north), we could be looking at a pressure build to our north east towards week 3. 

[Summer Sun]

UKMO once again shows high pressure becoming more influential across all areas over time temperatures especially in the south will be recovering back up to the high teens maybe just into the low 20's

 

Edited May 18, 2015 by Summer Sun

[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 MAY 18TH 2015.

 

THE CURRENT GENERAL SITUATION A showery West to Northwest airflow will follow a cold front SE across Southern England today with a Low pressure centre drifting across Northern Scotland later today and tonight.

 

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

 

MODELS-2 WEEK HEADLINE Slowly becoming drier and brighter with rain at times restricted to the far North from early next week.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream is currently slipping South across the UK as a trough of Low pressure migrates away East from the UK midweek. It then slowly reverts to a more Northerly latitude, probably to the NW of Scotland blowing in a NE direction next weekend and beyond as pressure rises from the South.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows a theme of High pressure gradually extending influence NE towards at least Southern Britain later this week and more nationally in Week 2. The weather will remain showery though for several days this week with a second weak front crossing South late in the week with a little rain for a time before the better weather arrives in time for the Bank Holiday Weekend. 

 

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

 

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

 

THE GFS CONTROL The GFS Control run also shows strong support for the operational's theme with an enhanced High pressure area lying across the UK next week. In the meantime the showery and cool theme of present will last till midweek before the better weather arrives in the South. However, it may take a few days for the better weather to get a foothold more nationally as a weak trough looks like flowing South across the UK with a little rain late this week clearing away in time for the Bank Holiday break.

 

THE GFS CLUSTERS The GFS Clusters show a strong indication that High pressure is likely to be in control of the UK weather in two weeks time centred near or over 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 this morning shows the cool and showery weather clearing away later in the week as pressure rises from the SW with fine weather in the South later in the week extending influence to all areas over the Bank Holiday weekend and probably holding on over the South at least into next week.

 

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

 

THE FAX CHARTS The Fax Charts show a cshowery Low pressure area over Scotland moving away east midweek as pressure rises under a ridge across Southern Britain later. there is another set of fronts shown to move down across the UK at the end of the week.

 

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

 

GEM GEM this morning shows High pressure developing just to the west of the Uk from later this week, tantalisingly close to give fine and dry weather for all but not close enough to prevent occasional troughs affecting the far north and NE from some light rain at times in still cool air here while elsewhere becomes rather warmer with time.

 

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

 

NAVGEM NAVGEM remains more tentative in it's spread of better weather over the extended weekend with a NW flow shown down across the UK with some troughs bringing a little rain at times in rather cloudy skies and still cool weather but the rain looks like being most restricted towards Northern and Eastern Britain.

 

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

 

ECM ECM today looks pretty good this morning with High pressure extending influence across the UK from the end of the Bank Holiday weekend. Before that the current showery and cool weather is shown to clear away midweek as a benign and quiet weather pattern develops later in the week before a weak front moving South early in the weekend is the precursor to the better weather likely nationally thereon.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  shows a large ridge of High pressure lying towards the UK from an Atlantic anticyclone in 10 days time.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The model output have shifted towards much more influence shown by the Azores High in week 2 first picked up some days ago by the GFS Ensemble pack and maintained now across much of the other output too.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKM & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 96.6 pts followed by UKM at 95.8 pts and GFS at 95.1. At 5 days ECM  leads UKMO with 85.8 over UKMO's 83.4pts with GFS at 82.2. At 8 days ECM remains the leader with 51.0 pts over GFS's 50.5 pts. Then at Day 10 GFS gains superiority at 34.2 pts over ECM at 33.5. 

 

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 The weather models this morning remain fairly optimistic that the UK will be heading for a period of better weather than currently being experienced from the end of this week. The showery Low pressure currently will move away East soon after midweek with benign conditions following under a Westerly breeze. The North could see a little rain especially at the end of the week as a front moves SE down over all areas with a band of cloud and very little rain likely in the South before all areas then see a more concerted extension to the good weather to affect all areas late in the weekend. Next week looks set fair for many with a ridge of High pressure from a High pressure fairly close to the UK affecting all areas with some sunshine and warmer conditions especially in the South while the far  North remains at risk from troughs skirting by just to the North but overall there will only be small amounts of rain pretty much everywhere after the next few days and while sunshine will possibly be in fairly short supply until later in the weekend it then looks like next week should feel quite summery for many.

 

Next update from 08:00 Tuesday May 19th 2015