HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY WEDNESDAY NOVEMBER 12TH 2014.
NEXT UPDATE THURSDAY NOVEMBER 13TH 08:00
THE CURRENT GENERAL SITUATION Troughs will clear NE over the UK today with a showery SW flow following. Tomorrow sees a strong South flow ahead of a further Active trough arriving from the SW later.
MODELS-2 WEEK HEADLINE Unsettled with rain at times across the British Isles especially over the South and West at first and the North and West later. Drier and slightly colder weather over the North and East for a time from this weekend.
THE JET STREAM ENSEMBLE FORECAST The GFS Jet Stream Ensemble forecast shows little sign of any significant shift in the flow from it's 50-55 deg North location with a split flow for a time with a weak Northern arm travelling East over the Arctic Circle. The flow will blow with varying strengths and orientation this side of the Atlantic the only changes through the period.
GFS OPERATIONAL As of previous runs the run concentrates on two different elements of unsettled and wet weather over the two week period. The first week sees Low pressure on Southerly latitudes, mostly near Southern Britain with rain and showers for all as a result in generally mild conditions in a South or SE wind. Over week 2 more mobility is shown as Low pressire migrates towards the NW with SW and West gales featuring frequently in periods of rain and showers moving much more quickly East and average temperatures seeing all areas through to the end of the run and beyond.
THE GFS PARALLEL RUN The GFS Parallel run is broadly similar in trend but does indicate a drier and mild period over some Eastern and SE Britain for a time early next week as pressure builds over Europe before the very windy and wet conditions arriving in the NW then spreads to all areas by the end of the run.
THE GFS ENSEMBLES The GFS Ensembles are much more akin to it's operational version with a very mobile and potentially stormy spell of weather likely over the UK in Week 2 with severe gales likely almost anywhere. All this of course following another 4-6 days of being under the influence of slower moving Low pressure as it drifts down towards Southern Britain over this period. Very late in the run pressure is shown to rise from the South over the South setting up drier and relatively mild weather then.
UKMO UKMO today shows Low pressure close to Southern Britain continuing to fill but remain influential enough to maintain rain at times over Southern Britain. A ridge of High pressure from an European Anticyclone lies West across Scotland early next week with dry and bright weather with some frost and fog possible up here.
THE FAX CHARTS The Fax Charts maintain that the UK skies will be governed by Low pressure with concoction of troughs moving gently North and NE across the UK. Innitially there will be strong winds in places but later pressure becomes slacker as Low pressure is shown to fill near Southern England with rain at times still for all well into next week.
GEM GEM shows Low pressure holding control over Southern England early next week as the current deep mid Atlantic Low drifts ESE slowly towards this position over the coming daysat the same tome as filling slowly. After a couple of days of ambling around over the South while the North gets breathing space from wind and rain under a ridge from the NE Low pressure gathers momentum again moving NE from the SW to return wind and rain to all areas again later next week. Temperatures though mild at first will probably fall back to more average levels later especially under the strong SE flow over the North late in the run.
NAVGEM NAVGEM keeps Low pressure domination across the South of the UK with a deep centre over the Atlantic drifting down over Southern England by early next week filling steadily. As with GEM rain for all at first will become more restricted towards the SW for a time before a renewed Atlantic attack returns NE across the UK later as High pressure to the NE declines slowly later at the same time as receding SE.
ECM ECM this morning continues it's recnt run of different evolutions to the rest of the models, this morning showing a slow rise of pressure late in the run under complex synoptics which sees a cut off Low near the West of the UK at the end of next week with rain at times and a slack and benign look to the UK synoptics at the end of the run with a lot of dry if benign and cloudy type weather under pressure that has risen sufficiently to develop a High centre to the NW at the end of the run in average temperatures.
THE ECM ENSEMBLES The Ensembles point to a SW flow of some sort the most likely outcome covering the UK in 10 Days time in association with Low pressure over the NW Atlantic and higher pressure over Europe. No doubt that troughs of Low pressure will lie somewhere close to the UK delivering rain at times in continuing mild conditions.
NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend today generally focuses on maintained unsettled weather but with a change of emphasis of rain shifting from the West and South more towards the North and West as SW gales develop later.
MY THOUGHTS The pattern of weather has shifted away from anything colder moving towards the UK in preference to a more mobile and potentially stormy spell of weather through the second half of this morning's output as Low pressure close to Southern Britain early in the period is absorbed by strong and deep Low pressure centred more towards the NW of Britain later which forces the High block to the NE to collapse SE and bring fast moving spells of heavy rain and strong winds East over all areas coupled with potentially stormy conditions. As always there are exceptions to this as there are some options that show High pressure possibly building from the South later and bringing drier and mild conditions into the South at times later. Also ECM continues to be different and brings a more universal rise of pressure over the UK late in it's operational run resulting in a slow dry out of current conditions into quiet and benign conditions in average temperatures if it verifies. It's Ensemble pack bases itself shows Low pressure being likely to be positioned to the NW in 10 Days time with a SW flow and troughs continuing to carry rain at times most prolific towards the North and West. So very little support there from it's operational again. In my opinion this morning the overlying support lies with Atlantic based weather continuing over the UK for the next two weeks with a shift in emphasis of the worst weather likely to shift to the North and West as the High pressure block to the NE largely collapses in the second week. The trend is also for more mobility to the sytems as they look to zip East quickly later on a strong Jet over the UK with severe gales at times offered from some output. The only grain of comfort for a pattern shift to something chilly is flown by the GEM operational today as it shows the cold block to the NE holding back the push from the Atlantic across the UK. However, without much support it really is a candle in the wind this morning.
Martin G
Kilmersdon Radstock Bath Somerset