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 AUG 5TH 2015.
THE CURRENT GENERAL SITUATION. A weakening depression will move NNE to the West of the UK with weakening troughs tracking slowly East across the UK today and tonight, clearing to the NE tomorrow
http://www.wetterzentrale.de/pics/Rtavn001.gif
MODELS-2 WEEK HEADLINE Remaining rather changeable with rain at times especially over the North and West. Some lengthy dry and at times warmer conditions across Southern and Eastern Britain perhaps extending North for a time later.
THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the flow moving NE across the South of the UK over the coming days. The flow then realigns more west to east across the North of the UK, still moving further South at times in the first week. the flow is then much further North for a time later but never achieves a position quite far enough to the NW to eliminate some of the UK falling under it's more unsettled accompaniment.
http://www.netweather.tv/index.cgi?action=jetstream
GFS OPERATIONAL The GFS Operational Run today continues to indicate somewhat better conditions than of late with a finger of High pressure from the Azores anticyclone ridged towards Southern England for a lot of the time from the weekend. Unfortunately it is often a couple of hundred miles too South to eliminate the effect of continuing Atlantic fronts from crossing Northern Britain and these also feed down into the South on occasion with a little rain here too at times. Often quite warm conditions in the South will be interrupted by fresher air as any troughs move through the South at times.
http://www.wetterzentrale.de/pics/Rtavn1441.gif
http://www.wetterzentrale.de/pics/Rtavn3841.gif
THE GFS CONTROL The GFS Control Run shows a ridge too developing close to Southern Britain with things warming up down here and becoming quite humid and sometimes rather cloudy over the weekend and next week. The North remains more changeable for a time before a better spell develops here too midweek next week as a ridge extends influence across many areas. Thundery low pressure then moves up from the South with thundery showers for a time before the weather settles down again under High pressure later in the period with many places then becoming fine, sunny and warm.
THE GFS CLUSTERS(14 Days) The GFS Clusters this morning for 14 days from now look fairly good with a lot of High pressure close by to the South and SW with 25% of members placing High pressure across the UK so a lot of fine weather for many areas likely in two weeks time with any unsettled conditions likely in the far North.
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 ridging across the far South at the weekend from the Azores High bringing warm and humid weather to Southern Britain while the North lie under moist and damp WSW winds. By the end of the 6 day period High pressure has migrated to the East of the UK with a period of slack and light winds for most areas and the small possibility of a thundery shower in the extreme South within the generally warm conditions.
http://www.wetterzentrale.de/pics/Rukm1441.gif
THE FAX CHARTS (to 84hrs) The Fax Charts this morning show weakening fronts moving NE across the UK over the coming days ahead of High pressure building close to Southern Britain by the weekend.
http://www.weathercharts.org/ukmomslp.htm#t120.
GEM GEM this morning does show he build of pressure close to Southern Britain at the weekend delivering a spell of fine and warm if often rather cloudy conditions for a while. Further to the North things remain more changeable and breezy and it isn't long into next week before all areas become rather cooler again with occasional rain at times, still more likely across the north and West than elsewhere especially late in the period.
http://www.wetterzentrale.de/pics/Rgem2401.gif
NAVGEM NAVGEM shows the build of pressure too from the SW across the far South of Britain at the weekend leading on to weaken it briefly in the early days of next week to rebuild it further North by Wednesday to extend more settled and warmer conditions to many areas, not just the South by then.
http://www.wetterzentrale.de/pics/Rnvg1681.gif.
ECM ECM this morning offers up a similar package of better conditions as a ridge moves across the far South at the weekend with fine, humid and warm conditions for a while though the North at this stage stays breezy, cooler and more changeable. As the ridge pulls away East next week an area of slack pressure gradients develops across the UK with light winds, warm conditions and an increasing chance of showers as we move from the midweek period to the end of the run when cooler air looks like extending back to many areas.
http://www.wetterzentrale.de/pics/Recm2401.gif
ECM 10 DAY MEAN The ECM 10 Day Mean Chart this morning shows the same pattern as previously for the position we're likely to lie under in 10 days time. Low pressure is shown up to the NW with a trough close to Western Britain with slack winds across the UK. With pressure between it's members averaging under 1015mbs UK wide some rain or showers can be expected, still probably focused most towards the NW.
http://www.wetterzentrale.de/pics/Reem2401.gif
NOTABLE TREND CHANGES FROM PREVIOUS RUNS Though improvements continue to be shown from most models in the shape of High pressure ridging from the SW the axis looks too far South to affect all areas on much of this morning's output.
31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM. This morning's verification statistics show ECM leading the way at 3 days with 95.9 pts followed by UKMO at 95.4 pts and GFS at 94.7 pts. At 5 days ECM is stll king at 86.0 pts followed by GFS at 83.3 and UKMO at 83.2 pts. Then at 8 Days ECM still leads at 58.4 pts over GFS's 53.0 pts. Finally at Day 10 ECM leads GFS at 39.4 pts to 33.7 pts from GFS.
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 All models show a High pressure ridge building towards the far South of England during this coming weekend and bringing warm and humid air up across much of Southern Britain at the weekend though wall to wall sunshine is unlikely under often large amounts of cloud. In the North things look much more changeable still as a strong WSW flow delivers a lot of cloudy and damp weather for a time. It's what happens to the High pressure in the South after the start of next week which determines whether the North shares in the better weather or not as too much output for my liking push the High pressure away to the East too quickly which allows lower pressure to reassert some influence across the UK by the mid to end of next week with the inevitable showers scattered about. I still feel the Jet stream remains a factor in this dilemma as although blowing further to the Northwest than it has for some considerable time next week it remains close enough to put pressure on the extent that warm conditions are allowed to push up across other areas of the UK away from the far South and SE. Nevertheless, there is some output that do build a second ridge on a much more Northerly trajectory next week which would include the North becoming fine and warm so all is not lost for you folk in the North. The problem is though that hemispheric synoptics do not seem ideal to hold things in a static positions with regard to High pressure near or over the UK with all output having the desire to pull back some Low pressure and cooler temperatures at some point, most likely from the West and NW. So while I remain optimistic about some improvements, certainly in the South and less so further North I won't be shouting from the rooftops that a prolonged very warm and settled spell is likely across the UK yet as there remains too many 'if's and but's' in the projections but I think most places should see some reasonable weather over the coming week or two without it ever becoming mesmerising.
Next update from 09:00 Thursday Aug 6th 2015
Martin G
Kilmersdon Radstock Bath Somerset