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 MAR 6TH 2016
THE CURRENT GENERAL SITUATION A chilly North or NW flow will continue across the UK for the next day or two with a disturbance running South close to Western Britain late today and for a time tonight.
http://www.wetterzentrale.de/pics/Rtavn001.gif
CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the UK will remain around about the 2000ft mark for much of the weekend but maybe a little higher than this across the far SW for a time late today and tonight. Snowfall amounts will be small or negligible for most through this weekend with any snow light and fleeting over higher ground exposed to the Northwest, North and NE.
http://www.snow-forecast.com/maps/dynamic/uk
http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif
MODELS-2 WEEK HEADLINE Rather cold and breezy at first with rain or showers at times with snow on hills. Gradually becoming more settled and less cold then with bright days but cool possibly frosty nights.
THE GFS JET STREAM FORECAST The Jet Stream has a few more days of blowing South across or just West of the UK. By midweek the flow buckles NE and breaks off from the Southern element with the main arm then tracking NE well to the North of the UK becoming fragmented and variable in position and weaker in strength through Week 2 as High pressure lies close to the UK blocking any direct West to East passage.
http://www.netweather.tv/index.cgi?action=jetstream
GFS OPERATIONAL The GFS Operational Run's theme today is for the current cold Northerly flow to give way to a cold and very unsettled day Tuesday as Low pressure spins SE down across the UK with strong winds, heavy rain and hill snow possible for a time. Then the middle of the week sees milder and cloudy conditions with further rain at times before High pressure builds up from the South across all areas settling the weather down to fine and sunny weather but with some night frosts. Temperatures by day look quite respectable before a return to unsettled and changeable weather is featured to return towards the end of the period, moving in from the West and NW.
GFS CONTROL RUN The theme of the Control Run shows a similar evolution with High pressure taking control of the weather centreing close to the UK in the second week. Any Spring warmth may be more tempered by different positioning of the High more to the North and NE on this run with the possibility of chilly conditions returning from the East especially later with a cold ESE wind picking up across England and Wales.
http://www.wetterzentrale.de/pics/Rtavn1441.gif
http://www.wetterzentrale.de/pics/Rtavn3841.gif
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 GFS Clusters today show a bias towards High pressure probably most likely to lie close to SW Britain with it's influence stretching across much of the UK. Some members but a much less significant amount project the possibility of a cold Northerly with High pressure out to the NW but this is only shown by a 10% cluster.
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 a chilly wet period towards Tuesday and Wednesday as Low pressure moves SE across or just to the East of the UK with some hill snow still likely. Then a change to milder and lighter Westerly winds with some rain chiefly in the North sets up by next weekend with High pressure increasingly influential just to or over the South by the end of it's 6 day period.
http://www.wetterzentrale.de/pics/Rukm1441.gif
THE FAX CHARTS The Fax Charts show a very slow change to the pattern across the UK in the next 5 days. In the process will be several days of troughs straddling the UK from the NW then west with rain at times for all and cold enough for some snow at times on the hills up to midweek before the milder air off from off the Atlantic wins out later this week.
http://www.weathercharts.org/ukmomslp.htm#t120
GEM GEM this morning maintains the theme shown by GFS today in changing the orientation of movement of Low pressure systems away from the SE direction they have taken of late to a more easterly direction much further North of the UK. This has the effect of cutting off the cold NW or North feed and replacing it with milder Atlantic Westerlies. Pressure is then shown to build from the South by next weekend with a sustained spell of dry early Spring weather with sunshine by day but with an increasing likelihood of the return of chillier air and frosts at night as the High responsible migrates out to the NE of the UK later.
http://www.wetterzentrale.de/pics/Rgem2401.gif
NAVGEM NAVGEM too shows milder conditions take hold after a chilly and wet period towards midweek. High pressure then builds NE across Southern Britain gradually extending to many areas by next weekend. With a source of winds by then from the SW temperatures should recover to average or perhaps a little above by day although patchy night frosts may still be possible.
http://www.wetterzentrale.de/pics/Rnvg1681.gif
ECM ECM today follows the theme too with High pressure steadily building North across the UK by next weekend following the messy transitions from the current rather cold pattern with rain and patchy hill snow between now and more especially midweek. As High pressure builds a spell of Westerly winds and rain at times affects the North before all areas settle into dry and fine almost Springlike conditions with light winds. There is still plenty of scope for night frosts to occur and later in the run as the High drifts further North it maybe that temperatures by day fall back somewhat too as uppers cool a little and an Easterly feed to the wind might develop.
http://www.wetterzentrale.de/pics/Recm2401.gif
ECM 10 DAY MEAN(12z) The new 240hr mean Chart seems late on release this morning but the main theme of the last night's chart seems unlikely to be changed much this morning given the Operational's message which has High pressure ridged strongly across the UK with a fine and benign weather pattern expected across the UK in 10 days with average temperatures at least for most parts.
http://www.wetterzentrale.de/pics/Reem2401.gif
NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The trend is well set for the weather to become fine, settled and less cold from the middle of the week with solid cross model support for High pressure to build across the UK.
31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.6 pts with UKMO at 99.5 pts and GFS at 99.4 pts. At 3 days ECM is leading with 97.6 pts to UKMO's 96.9 pts while GFS lags behind at 96.1 pts. At 5 days ECM leads with 90.7 pts to UKMO at 88.2 pts and GFS at 85.9 pts. Then at 8 Days ECM has the leading spot from GFS with 64.9 pts to 60.5 pts. Finally at Day 10 GFS has the lead from ECM with a score of 48.2 pts to 46.8 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 There is considerable cross model support for a change of weather type as we move through this week with Wednesday or Thursday looking the likely day of transition. What we have now is the same rather cold and unstable NW airflow down across the UK with various disturbances threatening the UK with rain and hill snow at times. However by midweek a shift of the South flowing Jet stream to a less strong West to East flow North of the UK looks probable allowing rising pressure from the South to gradually extend it's influence at first to the South by the weekend and later to all areas with the possibility of a strong High cell sitting directly over the UK in a week or so. It would be too easy to say this will mean wall to wall sunshine and high Spring temperatures but we have to remember it is only March and cloud amounts could scupper this element of proceedings but nonetheless there looks like being a period of sustained dry conditions with light winds. Clear skies at night could allow for some night frosts but daytime levels look like being average at worst as hinted at before dependent on cloud amounts. Then as we look further out into the second week signs that the High might want to regress towards the NE North or NW are all shown by some output so the general feeling is that while staying dry temperatures could fall back somewhat as winds settle from an easterly or NE quadrant. This is all a long way off but it is nice to see sound cross model support for a period of High pressure to allow the extra hours of daylight and lower humidity values expected to dry up the ground in preparation for the Summer growing season.
Next Update Monday March 7th 2016 from 09:00
Martin G
Kilmersdon Radstock Bath Somerset