HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON WEDNESDAY MAY 4TH 2016
THE CURRENT GENERAL SITUATION Pressure is high over Southern England today as a couple of cold fronts move very slowly East across Northern areas today and tomorrow while weakening and eventually decaying in situ by Friday. A thundery Low pressure area will then develop to the SW of the UK resulting in a warm ESE flow across the UK by the weekend.
http://www.wetterzentrale.de/pics/Rtavn001.gif
CURRENT SNOW FORECAST AND/OR FREEZING LEVEL OVER THE UK The UK continues to see the freezing level across the UK rise to as high as 10000 feet across the South by the weekend while levels are slower to rise in the NW where they remain around 5000ft before rising to 7000ft or above by the weekend.
http://www.snow-forecast.com/maps/dynamic/uk
http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif
MODELS-2 WEEK HEADLINE Becoming warmer with the risk of some thundery showers in the South at times later.
THE GFS JET STREAM FORECAST The Jet Stream currently moving NE across the NW of the UK will weaken in the coming days with the main cyclonic flow around Spain becoming the driving force over the weekend and next week before the flow becomes very light and split across the Atlantic and NW Europe with no clear definitive structure shown within the latter end of the forecast period this morning.
http://www.netweather.tv/index.cgi?action=jetstream
GFS OPERATIONAL The GFS Operational Run today still shows a lot of Northern blocking anticyclonic patterning over the next few weeks. Pressure will be lower across Southern Europe and later other parts of Europe too with the best weather eventually likely to be in the NW. In the meantime the weather will be much warmer than of late with sunny spells but with the likelihood of some thundery showers at times especially in the South but not everywhere will see them. Eastern Coasts continue to look like seeing a lot of fret and here it will be rather chilly for much of the time in an onshore breeze and on this run all areas become cooler at the end of the period as cold North or NE winds and Low pressure feed down the North Sea in two weeks time with some rain or showers.
GFS CONTROL RUN The theme of the Control Run is very similar to the Operational for the next 10 days with warm and later humid weather with some thundery rain in places especially in the South. Then the run diverges late in the run as a more traditional pattern of Low to the NW and South-Westerly winds reset across the UK with the best weather reverting to Southern and Eastern areas.
http://www.wetterzentrale.de/pics/Rtavn1441.gif
http://www.wetterzentrale.de/pics/Rtavn3841.gif
http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=144&mode=0&carte=0
http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=384&mode=0&carte=0
GFS ENSEMBLE DAY 14 DATA The clusters today show the UK likely to be lying under an area of quite slack pressure biased towards lower pressure rather than high, so a lot of potential shower risk conditions in temperatures around or slightly above average with High pressure likely to be lying either to the NW, West or SW with the UK itself lying under shallow and showery Low pressure areas.
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 The UKMO model this morning shows Low pressure developing down towards Spain and Portugal over the weekend with a strengthening Easterly flow across the UK. This will feed up the risk of thundery rain and showers towards the South and SW of the UK though most Northern and Eastern parts of the UK should stay dry and most areas it will become warm and humid. However, I cannot emphasize enough how much chillier it will feel near the East coast in an onshore and stiff wind with sea haar and fret persistent.
http://www.wetterzentrale.de/pics/Rukm1441.gif
THE FAX CHARTS The Fax Charts mirror the theme of the raw data well today showing warm SE winds and a lot of dry weather come the weekend with just the chance of a thundery shower in the South and especially the SW between hazy but warm sunny spells.
http://www.weathercharts.org/ukmomslp.htm#t120
GEM GEM this morning shows a similar pattern over the next week as Low pressure developing over Spain and Iberia deepens and strengthens an Easterly flow across the UK with some fine and warm weather for many but also with some occasional thundery showers across the South and West. Then towards the end of next week this Low over Spain is sucked away to the NE and backs winds off to the North or NE across the UK with much cooler and unsettled weather with cold rain and showers at times spreading to all areas at the second weekend.
http://www.wetterzentrale.de/pics/Rgem2401.gif
NAVGEM NAVGEM today shows the same Low pressure area down to the SW of the UK by the weekend pumping warm East to SE winds up across the UK with warm sunshine and well scattered thundery showers especially in the SW at first but to many more areas by the middle of next week as the pattern tries to reset to a more traditional UK pattern of Low pressure to the NW and High pressure to the South though it seem unclear whether such an attempt would be successful or not from the Day 7 Chart.
http://www.wetterzentrale.de/pics/Rnvg1681.gif
ECM ECM today shows warm weather developing later this week as the High pressure area currently near the South moves east and then North into Europe. The developing East or SE flow in association with deepening Low pressure over Biscay and Spain sends winds into the East with warm and humid conditions extending North across the UK by the weekend with some thundery showers at times down over the South and SW. Longer term changes look very slow this morning with the Spanish Low transferring into the Med and other parts of Europe maintaining an Easterly feed and the risk of showers across the South of the UK while the NW sees the best weather at the same time as all eastern coasts remain cool and misty.
http://www.wetterzentrale.de/pics/Recm2401.gif
ECM 10 DAY MEAN (12z) The 240hr mean Chart from last night shows no pressure system having overall control though the theme of maintaining lower pressure across Europe and higher pressure just to the West or NW of the UK remains with the likely weather being rather showery in average temperatures at worst.
http://www.wetterzentrale.de/pics/Reem2401.gif
NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The theme remains for a warm and humid period of weather across the UK which could last for quite a while as High pressure is themed towards Northern latitudes and Low pressure likely to lie across Southern and Eastern mainland Europe.
31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.6 pts with UKMO at 99.4 pts and GFS at 99.3 pts. At 3 days ECM is leading with 97.3 pts to UKMO's 96.5 pts while GFS lags behind at 95.6 pts. At 5 days ECM leads with 89.1 pts to UKMO at 87.1 pts and GFS at 83.4 pts. Then at 8 Days ECM has the leading spot from GFS with 62.5 pts to 53.0 pts. Finally at Day 10 ECM has the lead from GFS with a score of 46.1 pts to 39.2 pts.
http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png
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.png
MY THOUGHTS The theme of the models remain largely unchanged this morning with the main theme being Low pressure to the South of the UK and the continuation of once established High level blocking to the North of the UK with an East or SE flow developing across all parts of the UK by the weekend. We are not there yet though and the North and NW will continue to see a few more days of Atlantic SW winds and rain at times as weakening fronts approach from the West. These then dissolve and decay come the weekend as the High pressure over the South currently drifts East and Southerly or SE winds push the warmer air NW to all parts. As already mentioned pressure will become low or even very low over Spain with some unseasonably wet and windy weather expected down there from the weekend and some out-feed of this will move North towards the South and West at times in the form of thundery showers from the weekend. Elsewhere there will be a lot of warm, and in places very warm and humid conditions with plenty of hazy sunshine that is of course if you live away from the East Coast as in these places any chance of warm weather will be thwarted by a developing haar which does look as though it could give days of cold, breezy and dull conditions especially the further North up the North Sea coast you travel. This pattern then looks fairly set for a week or so before looking longer term it does still appear that there could be a desire to shift the Spanish Low more towards mainland Europe and the Med with winds backing to the NE or even North and it could be that colder conditions will end up being fed South through the UK with some showers in the East later. Another option shown is the chance that pressure may rebuild to the South of the UK on the exit East of the Low pressure over Spain with winds trying to counteract the Northern High pressure blocking with a slow change towards SW winds and rain returning more towards the North and West later. All these long term options look very tentative this morning and should be used as a guide rather than a forecast but for now the next week or so looks pretty well set between the output which should ensure all areas away from the East coast becomes warm, occasionally sunny and bright if breezy with time with the chance of a few thundery showers in places-especially in the South. Enjoy.
Next Update Thursday May 5th 2016 from 09:00
Martin G
Kilmersdon Radstock Bath Somerset