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 SUNDAY MAY 15TH 2016
THE CURRENT GENERAL SITUATION High pressure lies just to the West of the British Isles with a slack and slackening further Northerly flow across the UK
http://www.wetterzentrale.de/pics/Rtavn001.gif
CURRENT SNOW FORECAST AND/OR FREEZING LEVEL OVER THE UK The freezing level across the UK will remain near 5000ft across the far east to above 6000ft in the extreme West with a slow rising of the level in the East over the next few days while the highest levels over the extreme West falling back somewhat towards midweek.
http://www.snow-forecast.com/maps/dynamic/uk
http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif
MODELS-2 WEEK HEADLINE After a dry start becoming changeable with rain at times.
THE GFS JET STREAM FORECAST The current slack flow in the Jet Stream will align West to East and strengthen markedly by midweek as it surges East across the Atlantic and Southern Britain by the end of the working week. After spending several days in this form it breaks up and becomes anticyclonic around the UK for a time in the second week.
http://www.netweather.tv/index.cgi?action=jetstream
NEW GFS OPERATIONAL The New GFS Operational Run today shows the current ridge of High pressure weakening over the coming days as Low pressure moves in from the West with rain for all by midweek. The period following that will keep the weather unsettled for all with rain and heavy showers at times on a Westerly breeze as Low pressure is maintained to the North and later NE. Eventually pressure rises with more settled conditions developing, first in the South and then all areas later as High pressure builds strongly to the North of the UK again late in the run with Low pressure from Spain to the Med bringing the risk of thundery showers up from the South in rather warm conditions in an Easterly flow.
http://www.wetterzentrale.de/pics/Rtavn1441.gif
http://www.wetterzentrale.de/pics/Rtavn3841.gif
GFS CONTROL RUN The Control Run follows a broadly similar path with the main difference being the less extensive spread of High pressure across the UK in the second week, instead restricting any improvements to the South and East albeit temporary before more Atlantic drives in towards the North soon after with no real change in pattern shown until the final day of the run.
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 clustering today for day 14 shows us back to Low pressure domination over the UK in 14 days time with the exact patterning uncertain while only around 15% of members indicate a more High pressure based pattern with a centre close to the 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 The UKMO model this morning shows an unsettled spell developing for the UK this week starting from Tuesday as rain spreads East across the UK from the West later on Tuesday and is repeated again later in the week and extending into next weekend in association with low pressure centred to the North of Scotland.
http://www.wetterzentrale.de/pics/Rukm1441.gif
THE FAX CHARTS The Fax Charts show the slack High pressure ridge across the UK currently subsiding away South over the coming days as winds back westerly by Tuesday. Troughs ganging up across the Atlantic make their way across the UK towards midweek with rain shown for all followed by spells of sunshine and showers in a Westerly flow with further troughs in the flow too bringing longer spells of rain too in very average temperatures for mid May.
http://www.weathercharts.org/ukmomslp.htm#t120
GEM The theme of GEM too is for Low pressure to bring a change to westerly winds and rain at times towards midweek with further spells of rain and showers under a similar guise through next weekend before better weather develops in response to a reversal of pressure patterns to one of High pressure to the North and Low pressure to the South brings an Easterly flow back to the UK by Day 10.
http://www.wetterzentrale.de/pics/Rgem2401.gif
NAVGEM NAVGEM continues the well worn message printed above from the other models in that unsettled weather from the west returns to all parts of the UK by midweek culminating in quite a deep Low pressure across or near the UK over next weekend with rain and showers for all in average temperatures.
http://www.wetterzentrale.de/pics/Rnvg1681.gif
ECM ECM today also shows the unsettled spell starting late on Tuesday with a period of 5-6 days of unsettled conditions with heavy showers and spells of rain in largely Westerly winds and near average temperatures. This run then shows a rapid change towards the middle part of the second week as High pressure builds rapidly from the South and settles just to the East with warmer and drier weather developing for many and probably lasting a while especially over the South and East.
http://www.wetterzentrale.de/pics/Recm2401.gif
ECM 10 DAY MEAN (12z) The 10 Day mean Chart from ECM shows a favouring of Low pressure lying across the Atlantic and High pressure to the South and SE of the UK with a bias towards changeable weather with the best conditions likely towards the South and East. However, there is some other options from the other members which are inclined to distort the overall patterning of the Mean chart today.
http://www.wetterzentrale.de/pics/Reem2401.gif
NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The theme from the models today continue to paint a more unsettled phase of weather to come before things become more uncertain thereafter.
31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.5 pts with UKMO at 99.4 pts and GFS at 99.2 pts. At 3 days ECM is leading with 97.3 pts to UKMO's 96.2 pts while GFS lags behind at 95.6 pts. At 5 days ECM leads with 88.6 pts to UKMO at 86.8 pts and GFS at 83.4 pts. Then at 8 Days ECM has the leading spot from GFS with 61.7 pts to 49.6 pts. Finally at Day 10 ECM has the lead from GFS with a score of 44.2 pts to 36.7 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 Over the last few days the models have changed little in their interpretations of events likely across the UK in the next week. The further out in the outputs as usual the greater the differences and reliability become but moving forward from now it is fairly certain that after a few more days of fine and benign weather if rather cool at times it is likely to become unsettled from the West by midweek with rain followed by showers moving bodily East through the UK from the Atlantic. This theme is reinforced by further Low pressure later this week with next weekend too looking pretty poor for reliability of dry conditions with showers for many and probably still some longer spells of rain thrown in for good measure. The patterning becomes rather less well defined thereafter with some output bringing better weather up from the South and as happened in the most recent warm weather event some output shows this High pressure being sucked North to lie to the North of the UK while to the South pressure falls with a resultant warm Easterly flow developing again, this option shown by GFS and GEM. In the extended term taking us out to day 14 and using GFS Clusters at Day 14 as an indicator a lot of Low pressure is shown to be in control of the weather over the UK with just 15% of members showing any form of High pressure to the North while ECM at day 10 still likes the idea of High pressure closer to the South and East where the warmest weather would reside while the NW sees rain and showers in a SW flow. Given the rather poor verification stats shown above for GFS in the longer term of late I will side with the more likely option shown by ECM for day 10 meaning that after an unsettled period with rain at times for all pressure will build from the South in the second week with fine and warm conditions gradually spreading up from the South and East to more areas with time. So in the meantime lets enjoy the next few days of reasonable weather before things turn somewhat soggy for some for a week or so at least. Join me for another installment tomorrow to see if there is any change to the general theme.
Next Update Monday May 16th 2016 from 09:00
Martin G
Kilmersdon Radstock Bath Somerset