Model Output Discussion - Spring 5th March Onwards 6z--->

[IDO]

Looking at the mean 2m temps for London as per recent days the temps look mostly average: 

 

Not much rain so a dry settled period upcoming till next weekend before the high gets slowly eased east. The three main models at D10 highlight this though timing issues:

 

  

 

As expected last night's ECM D8-10 was doing it's usual when facing a pattern change, that is over doing the amplification. It was an outlier compared to the mean:

 

12z:

 

This morning it moves towards the general consensus. Looking further ahead to D12/13 it is clear from the clusters that lower pressure becomes more of a driver:

 

 

However lots of scatter and difficult to get the general surface conditions from the GEFS at the moment. The JMA week 3-4 anomaly is not dissimilar, with a return to alternating ridge/trough combos in a general zonal flow:

 

 

So milder and cooler, drier and wetter, typical April weather I would have thought from around mid month.

[Summer Sun]

So milder and cooler, drier and wetter, typical April weather I would have thought from around mid month.

 

Yeah looking at the ensembles we have around 9 days of high pressure dominating giving a lot of dry and mild weather (warm in any sunshine) after the 13th pressure is shown to fall

 

 

After today its very dry until the 13th as you'd expect with high pressure dominating

 

[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 FRIDAY APRIL 3RD 2015.

 

THE CURRENT GENERAL SITUATION A triple point depression will slide SE across and away from SE Britain today and tonight with pressure building from the West across the UK tomorrow.

 

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

 

MODELS-2 WEEK HEADLINE Becoming settled and dry with some sunshine and average temperatures but with a risk of occasional night frosts.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream forecast indicates the flow being forced North well to the North of the UK over the coming days with a split flow next week with the northern arm harmlessly away towards Iceland and the increasingly influential Southern arm over Southern Europe easing North towards the UK with time as the Northern arm breaks up entirely for a time later.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows High pressure building over the UK in the coming days lasting in situ for some considerable time before sliding away slowly SE in Week 2 and allowing lower pressure to develop from the West and NW with rain and showers for all by the end of the run. Before that happens though there is a lot of dry, bright and perhaps reasonably warm conditions for all.

 

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

 

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

 

THE GFS CONTROL The GFS Control Run is very similar to the operational this morning, shifting the High pressure slowly away SE in Week 2 bringing some potentially warm Southerly breezes over the UK in the process before rain and more mobile SW winds develop in association with Low pressure affecting the UK by the end of the run.

 

THE GFS CLUSTERS The GFS clusters today show a lot of variability between the members with the majority still showing a High pressure bias close to the UK 14 days from now, although the positioning is unclear. There is an around 30% group which show a more mobile Atlantic flow similar to the main runs at the end of the period with rain at times for all as a result. 

 

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 High pressure well in control of the UK weather positioned over the South of England next week and sliding gently further to the SE at the end of the period but maintaining dry, settled and increasingly bright and potentially warmer conditions the deeper we move through the coming week.

 

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

 

THE FAX CHARTS The Fax Charts indicate High pressure developing close to Southern Britain early next week with settled and dry weather. There are a lot of weak and cloudy troughs within it's proxomity close to the UK with only a slow brightening of the weather likely under the otherwise benign conditions.

 

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

 

GEM GEM too just about holding sway over the UK by 10 days time although the High has slipped South towards France later next week before building slowly back across the UK by Day 10. Positioning of the High would allow brighter if not sunny conditions for many with temperatures pleasantly warm but having drifted far enough South the North might see frionts crossing East to the North with a little rain for a time.

 

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

 

NAVGEM NAVGEM holds High pressure close to or over the UK for much of next week with dry and fine weather for many with some warm sunshine. Then as the High slips slowly SE later more of a SW flow develops over the NW with a little rain possible.

 

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

 

ECM ECM is showing a more complex and changing shape of High pressure based weather across and around the UK over the next week. The general message shown is a lot of dry, bright and increasingly sunnier weather with temperatures climbing somewhat as the next week goes on dependant on the positioning of the High day to day and the previaling airflow over our heads. A shallow Low is shown to drift north over England in about a weeks time which then becomes the catalyst for a decline in conditions from the West as an Atantic depression deepens to the West of the UK in 10 days time and sets up a stronger and mild Southerly wind.

 

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

 

ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart is beginning to show the likelihood that High pressure may begin to slip away to the East or SE in 10 days time but up t that point fine weather prevails for most.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models continue to show a strong theme of High pressure over the UK from 48 hours time lasting for some considerable time before perhaps beginning to slide away SE or East late in the period.  

 

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 97.8 pts followed by UKM at 97.5 pts and GFS at 96.6. At 5 days ECM  continues to lead the field at 91.1 pts over UKMO at 90.5 pts and GFS at 87.9. At 8 days ECM remains the leader with 67.6 pts over GFS's 63.6 pts. Then at Day 10 ECM retains superiority at 49.0 pts over GFS at 47.0. 

 

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 High pressure period is now almost on our doorstep as the final day or two of cloudy and damp weather currently being experienced will be the last such days for some time. The models are all in unison in predicting High pressure to lie across the UK early next week with fine and increasingly bright weather setting up across the UK. Sunshine amounts continue to look problemmatical but there should eventually be some warm sunshine for all as the upper atmosphere cloud evaporates in drier air aloft with time. The weather should be dry for all away from the very far Northwest through next week and winds should be light. Then as we move towards next weekend the decline in High pressure begins and we have good agreement now on where the models think the High will move as it declines. It looks as though it will drift away East or SE, not a bad direction for the UK as it will probably draw some warm and humid air North across the UK as it goes and it could be some time before pressure falls suffciently enough to allow the invasion of rain bearing fronts from either the South, West or NW. There is some agreement that by 10-14 days things may look rather more unsettled across the UK with rain at times and breezier conditions but before that comes there is a good week to 10 days of very useable and pleasant Spring conditions and unlike previous days the incidence of frosts by night look somewhat less likely given the orientation and eventual movement of the High in relation to the UK shown within the output today.    

 

Issued at 08:00 Friday April 3rd 2015

[Milhouse]

The 6z GEFS mean is firming up on the idea of quite a prolonged settled period. High pressure to the west of the UK initially will only very slowly transfer over to the east of the UK. At the moment its too early to say if this will result in the first very warm waft of air coming from the south. That is because several ensemble members have a cooler easterly component developing which would restrict temperatures. But we are on the brink of the first proper pleasant settled spell of the Spring.

 

 

[Frosty.]

The Ecm 00z ensemble mean looks very pleasant all the way to T+240 hours with high pressure in charge. Looking at the next few days, it's going to slowly brighten up with more in the way of sunshine, especially by Easter Monday and it will feel pleasantly warm where the sun pops out. Looking further ahead, gradually less cloud with longer sunny spells and pleasantly warm but a risk of overnight fog patches and a touch of frost where skies clear, it's only the far northwest which could have weak fronts brushing around the top of the anticyclone, for many it's a fine outlook until around mid month.

[Frosty.]

Just had a look at the 6z op and there is a fantastic spell of weather from later next week into the following week with temperatures soaring towards the magic 70F, really great charts, well worth showing before the 12z rolls out, summery weather in April would be a nice bonus.

[I remember Atlantic 252]

Just had a look at the 6z op and there is a fantastic spell of weather from later next week into the following week with temperatures soaring towards the magic 70F, really great charts, well worth showing before the 12z rolls out, summery weather in April would be a nice bonus.

 

good charts Frosty, surely the last one 17th Apr off that setup would be higher than 20C? GFS underdoing maxes, 27C I would have thought in favoured spots

[Milhouse]

The GFS 12z is shaping up very nicely for the end of next week and into the weekend. Temperature wise it will take something exceptional to get the mid 20s at this time of year but id imagine many places would break 20s given the charts below. Spot the difference here for Friday and Saturday.

 

[Milhouse]

And the warmth continues into the following week thanks to high pressure intensifying over the near continent and keeping the Atlantic at bay.

 

[Frosty.]

good charts Frosty, surely the last one 17th Apr off that setup would be higher than 20C? GFS underdoing maxes, 27C I would have thought in favoured spots

I think favoured spots could hit 22c 72f if the 6z verifies. Amazing charts. BBQ weather, great to see the 12z heading the same way.

Edited April 3, 2015 by Frosty.

[J10]

The Final Alps blog for the season has been published.

 

this also shows High Pressure being suggested to dominate conditions over the UK into next week.

 

https://forum.netweather.tv/blog/189/entry-4882-alps-weather-forecast-3-april-2015/

[Snowy L]

Another GFS run showing a good 10 days of settled and mild weather, becoming warm towards the end of next week. Peaking at 23c

[summer blizzard]

I'm optimistic.

 

[Winter Cold]

Evening all

 

Uncertainty creeping into the outlook tonight with regards to medium to long term. Its turning into ECM vs GFS for next weekend and beyond.

 

ECM has been showing a breakdown towards next weekend and beyond with the high slipping east and the Atlantic returning for a few runs now. The 12z carries on the theme:

 

        

 

 

Whereas the GFS keeps the UK under high pressure for mostly the entire run. Completely different idea to where we are headed:

 

       

 

 

Will be interesting to see which is right but one model is going to have egg on its face soon! The new GFS does have a love-in with high pressure and this could be showing its hand again tonight. All through winter it was showing high pressure which never materialised. However, for balance, im yet to see a T240 ECM chart verify!! We shall watch with interest......

Edited April 3, 2015 by Winter Cold

[Winter Cold]

Another GFS run showing a good 10 days of settled and mild weather, becoming warm towards the end of next week. Peaking at 23c

 

We'll see, the GFs could be going off on one of its fantasies with high pressure. The temperatures are very optimistic i feel also. Hardly any chance of a GFS chart over 2 weeks away varifying. The 12z run tonight was above the other ensembles by a bit, especially towards the end where it was best case scenrio and well above the majority of ensembles which keep temps around 15c right to the end. London GEFS below:

 

[Frosty.]

The way I see it, why worry about the Ecm 12z breaking down the fine warm spell at T+200 plus when next week is looking so good? and it is looking very good with a strong anticyclone bringing pleasant warmth and long sunny spells with light winds and chilly nights with a risk of patchy fog and frost. All the models look good next week, longer term, I hope the Gfs is right but let's just enjoy next weeks pleasant weather while it lasts.

[Milhouse]

The ECM mean at day 10 keeps high pressure strong to the east and still influential over the UK.

 

[Winter Cold]

The GFS 18z run makes a move towards the ECM solution with a gradual breakdown into Atlantic weather by the end of the run. Pressure lowers over next weekend, although still slower than the ECM:

 

        

 

Not too bad in the South East into week two to begin with but then the run brings unsettled weather into the UK:

 

     

 

We shall see where this run sits in the GEFS shortly.....

 

EDIT:

 

London GEFS for the 18z are below. The run is towards the lower of pressure scenarios by the end but the mean also drops below 1020 by the 13th and a clear downwards curve there:

 

Edited April 4, 2015 by Winter Cold

[mushymanrob]

i couldnt have created a better evolution if i was god himself!

 

its looking very strongly like itll get slowly brighter, sunnier, and warmer...potentially very warm (for early april). some wonderful spring weather likely for us this next week... brilliant!

[Summer Sun]

Next week and into the following week looks very settled and becoming increasingly warmer and brighter as the high moves position and brings in more of a south easterly

 

 

Whilst some days temps don't reach the higher teens given any sunshine it will be very pleasant

[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 SATURDAY APRIL 4TH 2015.

 

THE CURRENT GENERAL SITUATION An anticyclone will move slowly East into and over the UK today and tomorrow.

 

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

 

MODELS-2 WEEK HEADLINE Becoming settled and dry with some sunshine and average temperatures but with a risk of occasional night frosts. Perhaps becoming more unsettled from the NW late in the run.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream forecast indicates the flow now much weaker and forced away to the NW of the UK as pressure builds over the UK. Later in the period the flow reignites somewhat to the NW of Britain and slips down over the UK later, strengthening further as Atlantic Low pressure to the NW drives it East across the UK.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows High pressure building over the UK in the coming days lasting across Southern Britain through most of next week before declining away SE through Week 2 introducing mild Southerly winds then cloud and rain moving across the UK from the Atlantic later.

 

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

 

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

 

THE GFS CONTROL The GFS Control Run is very similar to the operational again this morning, shifting the High pressure slowly away SE in Week 2 bringing some potentially warm Southerly breezes over the UK in the process before rain and more mobile SW winds develop in association with Low pressure affecting the UK towards the end of the run though easing again under a ridge by term.

 

THE GFS CLUSTERS The GFS clusters today still look very mixed this morning with a lot of High pressure affecting the UK conditions in 14 days with positioning of it very unclear while a reasonable group also indicating the chance of Low pressure possible to sit near to the UK with an Atlantic flow giving rise to rain in places.  

 

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 shows High pressure across the UK next week slipping slowly South after midweek and allowing more of a SW flow to creep across Northern areas with cloud and perhaps a little rain by next weekend.

 

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

 

THE FAX CHARTS The Fax Charts indicate High pressure developing across the UK over the coming days while on the Northern and Eastern periphery of this High weak troughs are shown to maintain a fair amount of cloud at times within it's circulation but with the best of the brightness in the West.

 

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

 

GEM GEM too shows High pressure across the South retreating South later next week with the fine weather gradually eroded in the North by stronger Westerly winds and rain at times. High pressure is shown never to be far from the South though with it building back across Northern areas again too by Day 10.

 

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

 

NAVGEM NAVGEM weaves High pressure into and around the UK over the next 4-5 days before it too declines it away to the South with Low pressure threatening the UK from the NW by Day 7.

 

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

 

ECM ECM completes the theme of High pressure well in control of the UK weather next week with fine and in places bright and sunny rather warm conditions, especially given winds switch to a Southerly quarter late next week as High pressure recedes SE. By the end of the run High pressure has slipped all the way SE to the Med allowing the ingress of Atlantic troughs and rain to move slowly East across Britain from the West.

 

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

 

ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart is continuing to show a slow decline of High pressure to the East and SE of the UK in 10 days as pressure gently falls across the UK

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models continue to show a strong theme of High pressure over the UK from 48 hours time lasting for some considerable time before perhaps beginning to slide away SE or East late in the period.  

 

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 97.8 pts followed by UKM at 97.4 pts and GFS at 96.6. At 5 days ECM  continues to lead the field at 91.1 pts over UKMO at 90.5 pts and GFS at 87.9. At 8 days ECM remains the leader with 67.3 pts over GFS's 63.5 pts. Then at Day 10 ECM retains superiority at 48.2 pts over GFS at 45.8. 

 

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 UK is slipping into a much quieter spell of weather now as all models show High pressure easing into the UK from the West. The problem is there is a lot of cloud trapped within it's circulation left over from yesterdays troughs and others over the next few days as they creep around the Northern and Eastern periphery of the High cell. Given we are now in April there is good confidence that with time more and more of this cloud will break up and conditions should steadily warm up by day especially in the West. This may well be enhanced to Southern areas later next week as a Southerly flow develops sending drier air from France up across parts of the UK. This Southerly flow then looks like switching more SW'ly next weekend and beyond with pressure gently falling to bring in the risk of more unsettled and changeable weather with near average temperatures and rain at times for many. It maybe then that we look like running the chance of a more NW/SE split in the weather later in April with the North and West at greatest risk of wind and rain at times and although this may creep down across the South and East too on occasion these areas look like continuing to see good and lengthy spells of dry and bright weather and in any sunshine some pleasantly warm days.    

 

Issued at 08:00 Saturday April 4th 2015

[Milhouse]

The GEFS and ECM means are quite similar at day 10.

 

[Captain Shortwave]

Fingers crossed that after the next few days we get a drier and brighter flow over the UK. A lot of cloud for many over the Easter period, it will also be quite chilly for southern and eastern areas with the wind off the north sea, milder in the north and west with a breeze off the Atlantic.

I suspect it will be Thursday onwards when we see a general improvement with a continental flow setting up.

 

This then persists in some degree until day 10 when Atlantic fronts might start to move erratically eastwards across the UK, but how quickly and effectively they progress is uncertain. At this point I suspect we might see the first 20C by next weekend if the charts continue in this vain.

Edited April 4, 2015 by Captain shortwave

[Frosty.]

Temperatures go up and up later next week into next weekend, becoming very warm across England and wales with temperatures into the mid to high 60's F according to the Gfs 6z as our UK based high pressure becomes centred to the southeast of the UK allowing a warmer southerly flow to bathe the UK but as time goes on, an increasing risk of heavy showers breaking out as pressure starts to fall.

In summary, an Atlantic high is currently pushing east into the UK and our weather will slowly become brighter and milder, from Tuesday it turns warmer with longer sunny spells but with a risk of overnight frost and fog, however, the risk of cold nights diminishes as we import warmer air from southern Europe by next Friday. The only exception to the above is the far northwest of the UK where weak fronts and cooler Atlantic air brush around the top of the high but for most of us its going to become very pleasant indeed for the time of year.

Edited April 4, 2015 by Frosty.

[Mokidugway]

Not directly related to models ,but has anyone noticed the cloud streaks of Scotland on sat 24 ,con trails ???..