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 THURSDAY FEB 18TH 2016
THE CURRENT GENERAL SITUATION The remains of yesterday's frontal trough will clear SE England this morning leaving all areas under a rather cold and somewhat showery Westerly flow.
http://www.wetterzentrale.de/pics/Rtavn001.gif
CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across much of the UK is close to the 2000ft mark. Snowfall will be restricted to hills above 600ft or so in the form of well scattered showers though perhaps a little lower under the frontal boundary over the SE at first.
http://www.snow-forecast.com/maps/dynamic/uk
http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif
MODELS-2 WEEK HEADLINE Some rain or showers at times with snow over hills. Temperatures mostly near or somewhat below average though with a few short milder interludes in the South.
THE GFS JET STREAM FORECAST The Jet Stream will surge West to East across the UK over the next few days and remain in a fairly similar position for some considerable while undulating 400-500mls North and South at times. Towards the end of the period there are signs that the flow could move well NW of the UK to lie in a NE flow near the Iceland region.
http://www.netweather.tv/index.cgi?action=jetstream
GFS OPERATIONAL The GFS Operational Run today still shows a generally rather chilly and changeable pattern across the UK through the next few weeks. Low pressure areas are shown to continue to pass to the North or down across the UK at times alternating with some drier and colder periods as ridges of High pressure pass over. The trend towards the end of the period appears to be for High pressure to become more influential from the South or SW for longer periods with cold frosty nights developing for many but with some compensatory almost spring-like sunny days in average temperatures between less active rain and shower bands.
GFS CONTROL RUN The Control Run today shows a trend towards very changeable conditions with some short cold spells with some snow for some alternating with equally short milder and rainier periods as several areas of Low pressure areas sink down across the UK at times and give bursts of occasional very cold NE winds on their rear side before milder winds from the West return for a spell again thereafter with an almost rinse and repeat pattern ending the UK cold and potentially wintry under a Northerly flow at the end of the forecast period with High pressure out to the West in the Atlantic.
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 have shown a marked increase in pushing High pressure previously well to the SW much closer in to South or SW Britain in 14 days time with rain bearing fronts and the Jet stream returning to more Northern latitudes. Only a 25% cluster indicate a colder Northerly theme down across the UK with Low pressure over Scandinavia with the other 75% showing variations upon the High pressure to the South and SW theme.
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 interesting set-up in that A) it delays the NW flow early next week as another Low that only NAVGEM replicates moves into the UK and keeps unsettled and wet conditions longer with colder air filtering down from the North across the UK early next week with snowfall gradually feeding further and further South towards midweek. and 😎 this delays the onset of the transitory ridge midweek that other outputs show.
http://www.wetterzentrale.de/pics/Rukm1441.gif
THE FAX CHARTS The Fax Charts today show the rather chilly Westerly flow currently across the UK chased away by advancing Atlantic milder westerly winds behind warm fronts moving East tomorrow. The weekend is then characterized by a frontal trough trailing across England and Wales with further rain and drizzle in mild air while Scotland becomes colder and more showery again, this extending quickly SE to all areas on Monday.
http://www.weathercharts.org/ukmomslp.htm#t120
GEM GEM today shows a Westerly component to the winds across the UK throughout the next 10 days. Whereas nothing distinctly cold is likely some colder periods with wintry showers such as is shown for early next week will occur at times under a general theme of rain or showers at times in average or fractionally below average temperatures for most of the time.
http://www.wetterzentrale.de/pics/Rgem2401.gif
NAVGEM NAVGEM shows a variation on a theme of Low pressure over Scandinavia early next week but in it's run absorbs a new Low moving in off the Atlantic to form a complex Low pressure over the UK midweek with rain and showers, falling as sleet or snow over the hills as temperatures fall after a mild weekend for many to levels near or somewhat below average at the end of the week long period covered by this model.
http://www.wetterzentrale.de/pics/Rnvg1681.gif
ECM ECM this morning is potentially the most wintry of the set this morning showing the theme of a mild and in places wet weekend yet again quickly replaced by windy and cold NW winds and wintry showers early next week. This in itself is then shown to be displaced by further Atlantic Low pressure feeding in from the WNW setting up a Low complex across the UK by next weekend. Pressure at this time is shown to be trying to build well to the North of the UK and if this develops could greatly increase the risks of more widespread cold weather and potential snow for many towards the end of the period if the Low pressure complex near the UK orientates itself favourably.
http://www.wetterzentrale.de/pics/Recm2401.gif
ECM 10 DAY MEAN The 10 day mean chart today shows the Jet stream a long way South in 10 days with Low pressure close to northern Scotland and High pressure well away to the SW. The UK looks likely to lie in a NW flow with rain or showers at times in temperatures near to or a little below average with snow a risk on hills of the North at least at times.
http://www.wetterzentrale.de/pics/Reem2401.gif
NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS There are many differences in evolution shown this morning of a broad Westerly based weather pattern between the outputs this morning with little specific cohesion between outcomes felt across the UK at the surface.
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 97.7 pts to UKMO's 97.2 pts while GFS lags behind at 96.6 pts. At 5 days ECM leads with 92.0 pts to UKMO at 89.9 pts and GFS at 88.8 pts. Then at 8 Days ECM has the leading spot from GFS with 69.7 pts to 65.4 pts. Finally at Day 10 GFS leads today at 51.6 pts to ECM's 51.2 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 Quite an interesting set of output this morning with no clear direction shown between different models as to where we might end up in two weeks time. The main message is still one of Atlantic domination but the disagreements are in the eventual positioning of both the Jet Stream and whether High pressure is allowed to build somewhat later in the period to the North of the UK similar to what this morning's ECM Operational run shows. These two factors will determine whether we remain relatively changeable with mild rainy periods alternating with colder showery ones whereas the ECM route could lead us into something rather more wintry for many towards he turn of the month. The Jury is well and truly out at the moment as the GFS Clusters in particular this morning has shown a marked shift in pushing the Jet Stream further North longer term and bringing less wet and relatively mild weather to the UK when compared to ECM who in their 10 day mean chart shows Low pressure stretching down across the UK from Iceland with a Jet Stream well South of the UK meaning wet and probably cold weather more likely from this model a pattern that looks unlikely to move towards the GFS Solution at day 14. So with such diversities shown between outputs longer term I can only be speculative in my predictions this morning but given the next weeks hemispheric profile I think ECM may have a better handle on the outcome and I would edge towards the fact that GFS may well edge towards a more ECM like outcome for later next week over the next few days. As is often the case and never a truer word said 'more runs are needed' before a better confidence in any one outcome beyond a week from now can be interpreted.
Next Update Friday February 19th 2016 from 09:00
Martin G
Kilmersdon Radstock Bath Somerset