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

[knocker]

A brief summation of the 00z GFS run.

 

Largely dominated by cyclonic activity with Lows running SW/NE bringing a SW/W flow over the UK apart from next Sunday when brief ridging occurs with temps around 18C. (although that's a bit pointless at this stage). It would appear that it's still quite happy for the upper mid Atlantic trough to bring more influence than the HP.

Chart weatherbell

 

Edited May 6, 2015 by knocker

[Captain Shortwave]

Still uncertainties on how the trough and ridge interact, specifically how the jet splits and hence how much of the low heights roll over the high and how much gets left towards the Azores.

The GFS pushes the trough through quickly and most of the UK is back in cooler Atlantic air by Tuesday, still a couple of days of warm weather where temperatures could reach the low twenties.

 

The UKMO on the other hand pushes low pressure quick;y north east, bringing rain to the north of the UK on Monday.

But it leaves a deeper low over the Azores, this then pumps up the ridge again into Tuesday, this looks similar to last nights ECM operational, hence by Tuesday

 

We begin to draw up a very warm southerly, especially over the south of the country.

 

The GEM sits between the two solutions and pushes a cold front south east on Tuesday, only for it to stall over the south and then push north as we see the Azores high push northwards again

 

If the Euro high can manage to build far enough north then there is plenty of very warm air to tap into, the issue is simply getting that situation going. 

 

The GFS ens are a mixed bag, some bring early warmth, some give a delayed and more potent southerly and some offer very little and keep a westerly pattern, though Sunday and Monday look warm whatever happens.

Edited May 6, 2015 by Captain shortwave

[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 WEDNESDAY MAY 6TH 2015.

 

THE CURRENT GENERAL SITUATION A complex area of Low pressure will move slowly away to the North and NE of the UK tonight and tomorrow with the strong Westerly flow gradually decreasing with time.

 

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

 

MODELS-2 WEEK HEADLINE Unsettled  at first with rain or showers. Becoming drier and warmer in the South and East for a time early next week.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream currently blowing NE well to the South of the UK over France and Spain continues to be shown to edge North towards and over the UK in the coming days blowing in a NE direction. It later shows signs of becoming lighter and more disorintated and diffuse in location.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows a gradual shift away from Low pressure dominance across the UK once we enter the weekend with pressure rising to the SE of the UK. After several more days of occasional rain or showers and blustery winds the weather looks like taking on a much more traditional NW/SE split as SW winds bathe the UK with rain restricted to the NW of the UK for much of next week and some fine and warm conditions likely to the South and East. Things are shown to become more unsettled again through the second week as Low pressure to the NW regains some control with rain at times in cooler air. 

 

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

 

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

 

THE GFS CONTROL The GFS Control run follows the operational quite closely today throughout the period with some quite cool and unsettled conditions shown to develop across the UK later in Week 2.

 

THE GFS CLUSTERS The GFS Clusters for day 14 today show almost universal support for High pressure to lie out to the West or SW of the UK with varying degrees of proximity to us with various options in conditions ranging from rain at times to dry and fine weather all in temperatures likely to be close to average.

 

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 things warming up from the weekend as High pressure to the SE becomes much more influential with some warm sunny spells across England and Wales with any unsettled conditions confined increasingly towards the far NW. 

 

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

 

THE FAX CHARTS The Fax Charts sing from the same hymn sheet as the raw data this morning pulling complex Low pressure away to the North and NE at the end of the weekend as High pressure builds from the SE.

 

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

 

GEM GEM this morning shows that once the current and early weekend Low pressure areas and their attendant unsettled weather move away later in the weekend the pattern becomes much more set as High pressure remains to the SE of the UK for the rest of the run with England and Wales seeing a lot of fine, dry and pleasantly warm weather while the North and West remain at risk of Atlantic troughs bringing occasional bouts of wind and rain at times here. 

 

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

 

NAVGEM NAVGEM too shows Low pressure gradually receding away towards the North and West next week with a lot of dry and bright weather for England and Wales between well spaced bands of rain which will occur with much more frequency in the North and West in stronger SW pr west winds.

 

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

 

ECM ECM shows changeable conditions interrupted early next week in Southern and Eastern Britain as a short spell of warm and more settled weather develops here due to a ridge of High pressure to the SE. however, it is shown not to last as Low pressure and achange of axis in the Jet stream pulls cooler Low pressure down across the UK later next week with wind and rain for all. 

 

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

 

ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart  from last night shows the change in orientation of the Jet stream later next week responsible for dragging more unsettled and cooler weather back to many areas late in the run with winds from a West or NW point.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS There remains mixed outcomes on the introduction and duration of the NW/SE split in the weather anticipated next week.

 

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 97.2 pts followed by UKM at 96.6 pts and GFS at 95.9. At 5 days ECM  leads UKMO with 87.9 over UKMO's 86.7 pts with GFS at 84.2. At 8 days ECM remains the leader with 57.2 pts over GFS's 54.7 pts. Then at Day 10 ECM gains superiority at 38.8 pts over GFS at 37.6. 

 

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 pivotal point on the weather outcomes from the models next week remains hinged on how much and how long the influence of High pressure developing to the SE of the UK has across the UK. Much of the output holds it just too far to the SE for my liking unable to sustain and spread it's influence much further than England and Wales through the early days of next week when it will no doubt become warm and quite humid in the South and East for a time. Scotland and Northern Ireland look unlikely to benefit much from this rise of pressure from the SE with a SW flow continuing to deliver changeable conditions here. Then for those looking for a sustained dry and warm period there is a worrying trend between the models that by the end of next week things could be turning unsettled and a good deal cooler again as the Jet Stream changes trajectory across the UK and drags cool and unsettled weather under Low pressure down across all areas later from the NW. This would mean the  North would probably still maintain the most unsettled conditions but all areas would become rather cool as the supply of warm air to the South is cut off. So no real sign of a sustained warm and settled period yet with a short period next week when things could feel summery enough across the South and SE for a time but at this early stage of the season the Jet stream fuelled by the Atlantic is not quite positioned far enough North or static enough to eliminate the prospect of Low pressure making inroads back across many areas of the UK at times.

 

P.S The ECM 10 Day Mean Chart for this morning highlights the cooler feel in 10 days well.

 

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

 

Next update from 08:00 Thursday May 7th 2015

Edited May 6, 2015 by Gibby

[Frosty.]

I hope the Ecm 00z is correct as it extends the warmth from the south through midweek unlike the Gfs which shunts the warmth east of the uk by tuesday, the ecm shows a very warm / locally hot spell through the first half of next week, especially for southern/southeast England with temps into the 70's F widely across England and Wales and even higher in the south, closer to 80 F for a time.

Edited May 6, 2015 by Frosty.

[knocker]

The ECM anomaly has certainly increased the influence of the Atlantic trough this morning bringing to an end the brief warm spell. But in the ext period the HP hits back.

Chart weatherbell

Edited May 6, 2015 by knocker

[Frosty.]

The Gfs 6z holds on to the warmth next Tuesday with mid 20's celsius for parts of the southeast / east anglia and although it then turns cooler and unsettled through the second half of next week as a trough swings down from the northwest, it's not long before high pressure returns with warm weather making a comeback through low res. The good news is most of the uk will have a warm up, especially England and Wales. Sunday looks fine and pleasantly warm and then mon/tues become even warmer, very warm in the south & east, this is a better run than the 00z.

Edited May 6, 2015 by Frosty.

[Milhouse]

Well the good news is that the models show much of England and Wales are set to experience the first widespread 20c+ spell of the season. Sunday is looking not a bad day either so some pleasant conditions are approaching, especially for those in eastern and southern england and the Midlands.

[049balt]

Have checked the gefs 6z and it looks very good from mid month onwards.

That is what I am seeing.

[Captain Shortwave]

Have checked the gefs 6z and it looks very good from mid month onwards.

The CFS has been consistently suggesting that high pressure will become increasingly dominant through Europe after mid-month. More mixed during the next 10-14 days though, and of course the potential warm up early next week won't necessarily be picked up considering the rest of the period is predominantly westerly based.

 

 

Weeks 1 and 2 look mixed or even unsettled at times before we finally see this weaken a typical Euro/Scandi high with an Atlantic trough set up taking place. 

Worth noting these weekly ensemble forecasts are usually pretty good, they predicted the cooler unsettled end to April from a long way off.

Edited May 6, 2015 by Captain shortwave
Fixed attachments

[Summer Sun]

Have checked the gefs 6z and it looks very good from mid month onwards.

 

JMA keeps hinting at high pressure building in from mid May as well

[knocker]

Not forgetting the last EC32 update was going for HP from about the 17th onwards to 5th June.which is consistent with the 00z ext. anomaly.

[Summer Sun]

CFS and ECM both showing a rise in pressure between the 18th and 24th

 

____CFS_________ECM_____

 

Charts WSI euro weather

[Frosty.]

The Gfs 12z shows increasingly fine and warmer weather from Sunday to Tuesday for most of England and Wales with Sunday becoming pleasantly warm and Monday turns warmer with air sourced from southern europe, into the low 70's F. Tuesday is the warmest day with 23/24 celsius in parts of the east/se. The north and northwest of the uk are cooler and more unsettled throughout and we all turn unsettled and cooler during the second half of next week.

Looking further ahead, a spell of high pressure gradually develops and it becomes pleasantly warm again.

Edited May 6, 2015 by Frosty.

[Milhouse]

Its looking like we will get 3 days of increasingly warm weather from Sunday to Tuesday before it all gets swept away by the Atlantic, but not before a nice taste of summer. Who said we could write off the first half of May for anything Summery

 

[summer blizzard]

Its looking like we will get 3 days of increasingly warm weather from Sunday to Tuesday before it all gets swept away by the Atlantic, but not before a nice taste of summer. Who said we could write off the first half of May for anything Summery

 

 

Looks humid.

[Stuie]

Seems pretty good agreement for Tuesday between the UKMO and ECM. That`s still pretty much FI but let`s hope we get there and something changes to keep the HP for longer than the expected.

 

UKMO 144

ECM 144

[Frosty.]

The Ecm 12z @ T+144 is a BEAUTY...no sign of a downgrade and the ecm continues to show warmer conditions than the gfs next Tuesday, if this verifies it will be the warmest day of the spring so far. Sun/Mon/Tues look dry with lots of sunshine for most of England and wales.

I hope we see many more charts like these during the next 4 months.

Edited May 6, 2015 by Frosty.

[legritter]

Well early next week looking like it could turn more settled and with some warmth .

but looking across over hudson bay area high pressure looks like sending some low pressure areas into the atlantic so we need some rise of pressure from our friend the azores high ,i said our friend i must be loosing it , but there are hints on the charts of that possibly happening ,but there again if the high sets up shop too far west we could get a blast from the north /west .

so more runs needed and its only early days yet , today as been drab and i hate that nagging wind ,STellas all round gang .

[ANYWEATHER]

The generally unsettled spell continues for the foreseeable future. What does catch my eye is the plume of warmth next week about Monday/Tuesday time which could well spark off some thunderstorms as cooler more unstable air moves in from the west. Ecm is more keen on the plume , gfs not so. In the great scheme of things this looks about as interesting as it gets if you like some weather action

[damianslaw]

It remains a predominantly unsettled outlook especially for the NW quarter of the country. The models show weak azores high influence come Sunday and into early next week, its strength undermined by trough action over the mid atlantic which looks like exerting greater influence forcing heights to quickly slip away into the continent, but not before a mini plume of sorts for the SE with perhaps temps creeping close to the mid 20's. The NW will languish under the influence of the atlantic cooler and wetter here - a very disappointing outlook for those in the NW (including Cumbria..).

[knocker]

Quite good news and not totally unexpected with the GEFS and ECM anomalies tonight, They both have the warm spell breaking down mid week with the Atlantic trough swinging east to bring the UK under it's influence with a cyclonic W/NW flow. But the good news it is that is quite transitory as the trough continues moving east into Scandinavia allowing the Azores ridge to build which becomes the dominant feature in the ext period.

charts weatherbell

Edited May 6, 2015 by knocker

[Captain Shortwave]

It remains a predominantly unsettled outlook especially for the NW quarter of the country. The models show weak azores high influence come Sunday and into early next week, its strength undermined by trough action over the mid atlantic which looks like exerting greater influence forcing heights to quickly slip away into the continent, but not before a mini plume of sorts for the SE with perhaps temps creeping close to the mid 20's. The NW will languish under the influence of the atlantic cooler and wetter here - a very disappointing outlook for those in the NW (including Cumbria..).

Maybe, just maybe warmth might just get north enough to affect most of the country on Tuesday.

The GFS looks the most progressive out of the models for bringing the Atlantic in, though it is a case of timing rather than anything else.

Impressive maxima for Tuesday even from the GFS

26/27C possible in the south east, low to mid twenties across England and Wales, including the north west. A little cooler in Scotland and Ireland with fronts pushing in here.

 

UKMO looks possibly better at day 5

 

So it still looks likely that we could see a very warm day for many on Tuesday.

[knocker]

Yes I agree Cs. From Saturday to Thursday the GFS has a sequence of lows running SW to NE between Iceland and Scotland around the ridge pushing ever nearer to Scotland as the ridge is nudged SE until mission accomplished by  Wednesday. One wouldn't place any bets on detail at this stage although a couple of warm days, particularly in the south and east of England certainly look probable.

[Frosty.]

The Gfs 00z is showing 3 fine days for most of England & Wales (sun/mon/tues) with high pressure becoming centred to the southeast across the near continent, this enables a surge of warmth from southern europe to pump north across the southern half of the UK early next week with 17-19c on Sunday, 21-23c on monday and 24-26c on tuesday. By midweek the temperatures are back down to normal and the weather becomes very unsettled and much cooler through the second half of next week.

Edited May 7, 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 THURSDAY MAY 7TH 2015.

 

THE CURRENT GENERAL SITUATION A weak ridge of High pressure moves NE over the Uk today replacing the showery westerly flow followed by a trough of Low pressure edging towards the SW tonight.

 

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

 

MODELS-2 WEEK HEADLINE Changeable with some rain at times but a dry and warm period across the South and East early next week.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream will ridge North across the UK to be blowing in a NE direction across the British Isles over the next 4-7 days. It then is shown to change trajectory at the same time as moving back South under a UK trough in Week 2 before becoming less defined in both strength and location at the end of the period.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows a period of warmer and more humid conditions developing over the latter half of the weekend and start to next week as pressure builds to the SE sending rain bearing troughs towards the North and West only in a Southerly or SW flow. However, this is shown to be shortlived as Atlantic Low pressure sweeps the warm air away East over Europe with a very changeable and cooler period following with strong Westerly winds and rain at times thereafter. In the latter stages of the run the unsettled theme continues with Low pressure close to the East of the UK and cool winds blowing over all areas. 

 

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

 

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

 

THE GFS CONTROL The GFS Control run once more closely follows the theme of the operational with the warm and dry theme for a time next week across the South and East slowly giving way to more unsettled and windy weather with rain at times as Low pressure crosses east to the North of the UK before the desire to bring cool uppers down across the UK late in the run is less marked than with the operational but still shown to affect the UK in a modified way.

 

THE GFS CLUSTERS The GFS Clusters show an 80/20 split in likely conditions two weeks from now in preference of a likely ridge lying across the UK from an Atlantic anticyclone with any rain restricted to the far NW but temperatures held close to average by a West to NW breeze. Only 10% of output shows anything resembling unsettled weather spreaading further South across the UK rather than just the 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 this morning shows things warming up at the start of next week as High pressure to the SE sucks up some warm and humid air across Southern and Eastern Britain. However, it looks unlikely to last long as the warm air is pushed away East by growing influence of Low pressure to the North and NW with stronger cooler winds and some rain for many by midweek.

 

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

 

THE FAX CHARTS The Fax Charts show a similar evolution with a complex array of troughs and Low pressure at the weekend with attendant rain and showers dissolving as a warm surge of air from the South embraces Southern and Eastern Britain early next week when 25C could be reached in the SE for a time.

 

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

 

GEM GEM this morning also shows the surge of warm air across the South and East early next week rather slower to give way to more unsettled conditions from off the Atlantic. However, it does eventually remove it away East with all areas eventually coming under the influence of a strong Westerly flow with rain at times, heaviest over the North. 

 

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

 

NAVGEM NAVGEM too shows warmer air across the South and East early next week shunted away East by a cold front midweek and a deep Low pressure to the NW of the UK by next weekend with strong winds, rain then showers for all together with cooler conditions.

 

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

 

ECM ECM shows warm and muggy air sucked up across the UK early next week, lasting several days before a thundery trough moves NE over the UK around the middle of the week with fresher cooler air moving NE over all areas. Conditions then continue to be shown to deteriorate as a deep Low moves East to the North of Britain with strong and cool West winds and rain or showers at times for all gradually clearing away from the SW late in the run. 

 

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

 

ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart  from last night shows quite a cool and changeable pattern looking likely in 10 days time with a West to East Jet flow likely to be blowing across the South of Britain, Low pressure close to the North and a blustery and chilly WNW flow across the UK with some rain or showers a risk for all.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models continue to suggest that changeable conditions look likely to continue for the next two weeks at least.

 

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 97.2 pts followed by UKM at 96.6 pts and GFS at 95.9. At 5 days ECM  leads UKMO with 87.8 over UKMO's 86.6 pts with GFS at 84.1. At 8 days ECM remains the leader with 56.8 pts over GFS's 55.0 pts. Then at Day 10 ECM gains superiority at 38.2 pts over GFS at 37.6. 

 

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 Things still look very changeable across the UK over the two week period of the output this morning with something for everyone at some point or another. The current theme of showers and rain at times have another couple of days or so to run yet as a new Low and troughs drift NE across the UK with rain tomorrow and showers on Saturday and blustery winds in places. Then the most pleasurable period of weather across the South and East of Britain looks like taking place between Sunday and Wednesday as building High pressure to the SE sucks up some warm and humid conditions from the South when 25C is possible in places for a time in the SE. Unfortunately it increasingly looks only a shortlived event and never reaches the NW as the Atlantic looks like biting back from midweek. The breakdown will probably take the shape of a band of thundery rain crossing England and Wales midweek and then followed by windier and fresher conditions as a deep Low sets up near North or NW Britain with cool and strong breezes for all bringing spells of rain and showers West to East across all areas late next week. The longer term models then look like carrying this theme on through Week 2 too with rain and showers and quite cool charts shown from the GFS extended runs and although some output show High pressure not too far away in the extended outlook the positioning of the Jet stream forecasted for that time along with poorly aligned High pressure probably to the West or SW indicates the threat of chilly winds from a NW point look most likely to be keeping the average temperatures going right out to the end of the run with the further threat of rain at times especially towards the North. 

 

Next update from 08:00 Friday May 8th 2015