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 APRIL 8TH 2015.
THE CURRENT GENERAL SITUATION High pressure continues to be centred across the UK drifting slowly East with light winds for all both today and tomorrow.
http://www.wetterzentrale.de/pics/Rtavn001.gif
MODELS-2 WEEK HEADLINE Becoming more changeable over the North with rain at times next week while the South and East stays largely dry and bright and possibly quite warm at times.
THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream forecast shows the flow well to the Northwest of the UK tracking NE between Scotland and Iceland. It sinks slowly South travelling NE across England at Wales at the weekend before drifting back slowly North early next week. Towards the end of the run this pattern becomes much more complex and eventually disjointed as pressure rises to the north of the UK too.
http://www.netweather.tv/index.cgi?action=jetstream
GFS OPERATIONAL The GFS Operational this morning shows High pressure over the UK moving slowly East and SE across Europe in the coming days with a light Southerly flow developing. A cold front moves East over the weekend with a little rain for all and an introduction to cooler conditions and a North/South split in conditions thereafter. The North will see SW winds and rain at times while High pressure maintained to the South and SE of Britain will return fine and dry conditions here before High pressure builds to the North and eventually NE of the UK later with Low pressure to the South sucking a cold and raw Easterly flow with some rain or wintry showers across the South of the UK in this run for two weeks from now.
http://www.wetterzentrale.de/pics/Rtavn1441.gif
http://www.wetterzentrale.de/pics/Rtavn3841.gif
THE GFS CONTROL The GFS Control Run is very different in Week 2 although the sequence of events in Week 1 is very smilar to the operational. the differences lie in High pressure not showing such a build of pressure to the North of the UK and maintaining the heights to the SE of the UK. This has a very different complexion on the weather than that shown by the operational run with the South and East often fairly warm and dry with some sunshine and just occasional rain while the North and West maintain more cloud and more frequent outbreaks of rain or showers in average temperatures.
THE GFS CLUSTERS The GFS clusters show variations on a theme of High pressure across the Atlantic with a NW flow down across the UK looking quite likely in two weeks time. The clusters disagree on the proximity of the High to the West with a bias towards it being far enough to the West to allow some unsettled and chilly NW winds being very possible with some rain or showers across 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 shows a Westerly flow with a few fronts crossing East early in the weekend followed by a rise of pressure across the South returning fine and dry weather here though cooler than currently. In the North the weather becomes breezy with some rain next week under a stronger Westerly flow.
http://www.wetterzentrale.de/pics/Rukm1441.gif
THE FAX CHARTS The Fax Charts put the meat on the bones of how the incoming troughs from the West early in the weekend and again early next week displace the current fine and warm Spring weather with something cooler and more seasonal with some wind and rain at times across the North and West early next week.
http://www.weathercharts.org/ukmomslp.htm#t120.
GEM GEM today shows High pressure slowly receding away East and South through the weekend and start to next week with colder and more changeable conditions likely to affect the North through next week and eventually to the far South too late in the run as a small but significant Low hugs the SE coast at 10 days on this run with resultant chilly and unsettled conditions likely in a cold NE flow ahead of High pressure slipping East into the UK from the West.
http://www.wetterzentrale.de/pics/Rgem2401.gif
NAVGEM NAVGEM shows a much more unsettled and windier pattern next week as the weekends trough and subsequent ridge open the door to stronger Westerly winds across all areas next week with rain at times for all from Eastward moving troughs, the rain always heaviest and most persistent across the North and West.
http://www.wetterzentrale.de/pics/Rnvg1681.gif.
ECM ECM today is much kinder synoptically next week with High pressure remaining well in control over or just to the East and SE of the UK next week. This would result in the weekends rain on the cold front being very brief before fine weather returns for many. Next week would then likely bring fine and rather warm conditions across the South with any rainfall restricted to the far NW with a slack pressure gradient likely at the end of the run still keeping the UK in a rather warm SW drift across the UK.
http://www.wetterzentrale.de/pics/Recm2401.gif
ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart on the face of it shows a slack Westerly flow across the UK but this is made up of various options ranging from High pressure close to the South and resultant fine weather to something rather more changeable under Low pressure to the North where rain at times is most likely.
http://www.wetterzentrale.de/pics/Reem2401.gif
NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trends shown within the models this morning is quite weak with a mixture of fine and dry options under High pressure to the South mixed with several evolutions of cooler and unsettled weather with a few cold scenarios too from GFS and GEM.
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 97.6 pts followed by UKM at 97.2 pts and GFS at 96.4. At 5 days ECM continues to lead the field at 90.9 pts over UKMO at 89.7 pts and GFS at 87.6. At 8 days ECM remains the leader with 66.5 pts over GFS's 62.6 pts. Then at Day 10 ECM retains superiority at 47.5 pts over GFS at 43.6.
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 current fine weather with high temperatures will come to an end at the start of the weekend as all models indicate a cold front pushing East across the UK bringing a little rain but a more significant drop in temperatures by some 5-7deg C. The weekend will be fine for the South once the rain clears whereas the North may stay somewhat more changeable from that point on and it's at that relatively early point in the output that differences between the outputs become apparent. There are a variety of options on the table for next week and beyond ranging from a strong Westerly with rain at times for all and fine weather under High pressure bringing a return to the conditions we have currently at least for Southern Britain later next week with even a few wintry scenarios spelled out, notably from the GFS operational in two weeks time and less dramatically by GEM in 10 days. Which scenario is correct is hard to call at the moment but my own feelings are that something along the lines of ECM or the GFS Control run may well be closer to the mark which will maintain a lot of dry and fine weather towards the South and East of the UK with some quite warm conditions at times whereas the North will see troughs flirting by at times delivering some rain at times in a stronger breeze. So all things considered I think that despite a few unsettled and unsavoury model runs this morning we will probably end up with quite respectable conditions in the South for a few weeks with some light rain on occasion and temperatures on the high side of average whereas the North finds fine and dry conditions much shorter lived and less reliable with temperatures more suppressed here to average.
Issued at 08:00 Wednesday April 8th 2015
Martin G
Kilmersdon Radstock Bath Somerset