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 29TH 2015.
THE CURRENT GENERAL SITUATION A cold front will clear SE England this afternoon with a Low pressure area over Scotland drifting East into the North Sea tomorrow.
http://www.wetterzentrale.de/pics/Rtavn001.gif
MODELS-2 WEEK HEADLINE Unsettled and changeable with bright spells and showers or rain, heavy and wintry on hills in the North at first. Becoming less cold and possibly drier later especially towards the South and East.
THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream is focused to blow on a much more Southerly track especially over the Atlantic and while well South of Britain too for a time it shows signs of moving North across Britain later as pressure rises over Europe.
http://www.netweather.tv/index.cgi?action=jetstream
GFS OPERATIONAL The GFS Operational this morning shows a very changeable period over the coming two weeks. The cold feeling weather at present will move away North behind a front moving North across the weekend and then the UK settles into a changeable pattern with all areas seeing at least a little rain at times under various mostly shallow Low pressure areas crossing the UK. The focus of most of it moving towards the North and West nearest to lowest pressure at times with some longer drier spells become established especially in Week 2 across more Southern and Eastern areas closest to higher pressure as it moves in at times.
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 general terms as it makes much more of an unsettled first week with rain and strong winds at times as a deep Low positions just North of the UK while week 2 shows High pressure establishing across the UK with fine and dry weather for many. While it will feel cool in Week 1 under wind and rain Week 2 should be warmer with more in the way of sunshine.
THE GFS CLUSTERS The GFS Clusters today show a lot of High pressure influence across the UK in two weeks time but the positioning of such being very unclear with the main focus of it being across the UK in the shape of a ridge from the SW, West or NE.
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 main message of the weather becoming rather warmer next week under a SW flow. Low pressure to the NW will ensure some rain falls at times for many with the North and West seeing the most but the South and East not entirely immune too.
http://www.wetterzentrale.de/pics/Rukm1441.gif
THE FAX CHARTS The Fax Charts show a battleground scenario developing from the start of the weekend as a cool ridge establishing from the North over the coming days only slowly gives ground to milder SW winds behind a series of occluded fronts edging very slowly North across the UK over the holiday weekend.
http://www.weathercharts.org/ukmomslp.htm#t120.
GEM GEM this morning shows quite changeable conditions across the UK over the coming 10 days. After a chilly start to the period Low pressure troughs and Low pressure itself moves North across the UK and introduces milder air which then persists through next week fuelled by a deep Low in the Atlantic for a time with Southerly winds.
http://www.wetterzentrale.de/pics/Rgem2401.gif
NAVGEM NAVGEM shows troughs to the SW moving slowly North at the weekend though it is shown to need several attempts before succeeding towards the end of the weekend leaving next week with rain at times associated with Low pressure drifting North to the West and slowly introducing less cold air on a SW flow to England and Wales at least later.
http://www.wetterzentrale.de/pics/Rnvg1681.gif.
ECM ECM this morning also shows unsettled weather through next week as Low pressure remains influential to the West of the UK. It should slowly become less cool especially in the South and there are signs of High pressure building across the UK towards the end of the run pushing the unsettled weather away to the NW by next weekend.
http://www.wetterzentrale.de/pics/Recm2401.gif
ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart from last night shows the Jet Stream likely to be back to the NW of the UK allowing higher pressure to the SE to restrict more unsettled weather towards the North and West of the UK with slow improvements to the South and East with generally less cool weather.
http://www.wetterzentrale.de/pics/Reem2401.gif
NOTABLE TREND CHANGES FROM PREVIOUS RUNS There is very little trend shown this morning between output with all models showing their own interpretation of fairly benign synoptics towards the end of 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 97.4 pts followed by UKM at 96.8 pts and GFS at 96.1. At 5 days ECM leads UKMO with 88.4 over UKMO's 88.0 pts with GFS at 85.4. At 8 days ECM remains the leader with 61.6 pts over GFS's 58.9 pts. Then at Day 10 ECM retains superiority at 45.1 pts over GFS at 43.5.
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 In the longer term this morning there appears to be no clear signals with a variety of options and synoptics on offer across the UK in the 10-14 days time block. In the short term although rather clearer signals are shown the devil will be in the detail and timing as the current cool and showery theme gives way to a ridge from the North on Friday. At the same time Low pressure down to the SW will be attemping to push occluded troughs North across the UK and introduce milder SW winds behind. It's progress looks slow and erratic and it may be early next week before the front reaches Northern Scotland. By that time the milder SW winds will have reached most other areas but with Low pressure likely to lie either to the West or NW further rain and showers at times look likely though SE areas may become rather drier late next week as pressure rises over Europe, a part of the theme that shapes the latter frames of the output runs this morning. The one common theme looks to be the rise of pressure across the UK most pronounced within the GFS Control run while the operational and clusters show improvements more marginal and then GEM and ECM showing their own versions of this theme at Day 10. So with no definitive clear decision of where High pressure will likely lie it makes it hard to pin down any detail on what type of better weather such a High might bring and where. However there is plenty of time for the models to sort that dilemma out and in the meantime we'll concentrate on the changeable pattern of the next week where most places will see some rain at times and things should slowly warm up too but it might take some while for warmer air to reach the far North and NE.
Next update from 08:00 Thursday April 30th 2015
Martin G
Kilmersdon Radstock Bath Somerset