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 SATURDAY SEP 26TH 2015
THE CURRENT GENERAL SITUATION An anticyclone will continue to build aacross the UK today and tomorrow.
http://www.wetterzentrale.de/pics/Rtavn001.gif
MODELS-2 WEEK HEADLINE Mostly settled and fine well into October.
THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the flow likely to remain well to the NW of the UK over the coming week or so where it blows NE across Iceland quite strongly. Later in the period the flow turns South across the UK in association of a trough developing near the United Kingdom.
http://www.netweather.tv/index.cgi?action=jetstream
GFS OPERATIONAL The GFS Operational Run today shows High pressure building across the UK currently and also across Northern Europe early next week. Fine and settled weather will reside for all. Through next week pressure falls over Southern Europe and an Easterly flow develops across the South. This fall in pressure affects the South of the UK in the risk of showers later next week. Then as pressure falls more significantly for all areas the High dissolves away and relocates to the NW of the UK allowing a surge of very cool and unsettled weather to move down from the North with the risk of some early snowfall for the Scottish mountains at times and some air frost at night where winds fall light and skies clear.
http://www.wetterzentrale.de/pics/Rtavn1441.gif
http://www.wetterzentrale.de/pics/Rtavn3841.gif
THE GFS CONTROL The theme of the GFS Control Run this morning follows a similar route in the next week with the South having a strong and gusty period of East winds late next week with some showery rain. This run departs from the Operational's route in Week 2 with somewhat less influence of a change to widely unsettled weather with some fine and dry if cool weather still around especially for the North where frosts at night would be prevalent while the South remain at risk from occasional showery rain as Low pressure flirts with Southern Britain at times.
http://www.meteociel.fr/modeles/gefs_cartes.php
THE GFS CLUSTERS(14 Days) The GFS Clusters this morning continue to show quite a lot of variability at the 14 day mark suggesting that the path is quite unclear in the longer term again today. There is a range of options that show High pressure remaining in control across Central and Southern areas with only the North seeing Atlantic's influence and rain while other members show a cocktail of synoptic's some good, some bad with a 15% group suggesting a Northerly similar to the Operational run.
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 anchored over the UK for much of next week maintaining fine and settled weather UK wide with mist and fogs at night with touches of frost too but much compensatory warm sunny spells for most in the afternoon's.
http://www.wetterzentrale.de/pics/Rukm1441.gif
THE FAX CHARTS The Fax Charts this morning support the raw data well maintaining a strong ridge across the UK for most of next week with fine and settled weather as a result.
http://www.weathercharts.org/ukmomslp.htm#t120
GEM GEM this morning is again largely supportive of the main of other model output in that High pressure remains in control for much of the period, moving first to the NE and then back West across the UK and eventually out into the Atlantic. After a stiff breeze in the South later next week and the risk of a shower the weather turns dry again for most towards the end of the period as a slack and chilly Northerly flow under a ridge keeps rain bearing systems away from the UK.
http://www.wetterzentrale.de/pics/Rgem2401.gif
NAVGEM NAVGEM this morning has High pressure dominant across the UK over the next week with only a suggestion at the very end of the period covering next weekend that a few showers could be approaching the SE from Europe as the High pulls back a little out into the North Atlantic.
http://www.wetterzentrale.de/pics/Rnvg1681.gif
ECM ECM this morning completes the set and shows High pressure close to or over the UK from now until the end of the period. The centre does shuffle around somewhat with a period of fresh and gusty East winds over the far South next week but only the risk of a few isolated showers in the extreme South for a time. This run attempts a retrogression of the High to the West of the UK through the latter half of next week but fails in this with the end of the period reflecting High pressure still strongly ensconced over Scotland and the North Sea with fine and dry weather for all with misty and cold nights for many but potentially bright and warm afternoons.
http://www.wetterzentrale.de/pics/Recm2401.gif
ECM 10 DAY MEAN The ECM 10 Day Mean Chart from last night shows a typical open pattern shown where there is obviously quite a split in the individual member's output meaning not too much can be read into this chart's showing today.
http://www.wetterzentrale.de/pics/Reem2401.gif
NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models remain little changed from yesterday with the majority showing sustained High pressure based weather across all areas with any breakdown likely to come very late in the period and quite unclear in nature.
31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ties with UKMO at 99.4 pts each with GFS coming in third at 99.2 pts. At 3 days ECM is ahead of UKMO at 96.5 pts to 96.4 pts while GFS lags behind at 95.6pts. At 5 days ECM leads UKMO at 86.4 pts to 86.3 pts then GFS at 84.3 pts. Then at 8 Days ECM still leads at 57.9 pts over GFS's 51.3 pts. Finally at Day 10 ECM leads GFS at 34.2 pts to 33.0 pts from GFS.
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 Overall there remains little change in the output this morning particularly in the short to medium term. High pressure is going to remain the dominant role player over the UK for a considerable time to come as the centre crosses the UK and away to the East and NE before reasserting itself near northern Britain late next week. The only caveat to the overall fine, settled and often sunny weather by day and cool misty conditions overnight is the increase of wind likely across Southern England later next week which could give a shower or two for a time but it's only GFS and GEM who show his risk to be anything of significance while the Euro's fight shy of this outcome and maintain dry and fine weather for all. Then looking further out into the second week we see GFS do a complete retrogression of the High pressure area away to the NW of the UK scenario within it's operational run which has been hinted at from quite a bit of the output at times of late. In this case it would feed very cool and unsettled weather down across the UK later in the second week with even some snow for the Scottish hills and mountains and of course frosts at night. However, this is unlikely to verify as cross model support within it's own members amounts to only 15% and is not supported either by ECM or only limply by GEM. So we are still looking like a week to 10 days and maybe more of fine and settled weather across the UK when rainfall amounts will be very small or non existent and while there will no doubt be some days of stubborn mist and low cloud to push out the away all parts should see a lot of daytime sunshine, quite warm in the afternoons and a continuation of chilly nights. Any chance of a significant change to wet and windy weather within the next two weeks this morning continues to look quite small within the output on offer today.
WORST CHART OF THE DAY 00z RUN
http://www.wetterzentrale.de/pics/Rtavn3361.gif
An unsavoury chart as the worst chart of the day today comes from the GFS Operational run at T+336hrs with a deep Low across Southern Britain having moved down from well Northern latitudes and delivering very cool, windy and often wet weather for all as a result.
BEST CHART OF THE DAY 00z RUN
http://www.wetterzentrale.de/pics/Rukm1441.gif
The best chart of the day has to be the UKMO 6 day chart as it illustrates how well established our currently developing anticyclone looks likely to be showing a centre across the UK next Friday with the continuing theme of fine and settled conditions for the whole UK with mist and fogs at night and perfect Autumn conditions for the UK as a whole, likely to last onward from this chart for several more days at least.
Next update from 09:00 Monday Sep 28th 2015
Martin G
Kilmersdon Radstock Bath Somerset