Good morning everyone. Here is the report of the midnight outputs of the NWP for this morning Saturday January 25th 2014 and updated and raised twice daily from my website at http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm
All models show Low pressure moving across the Atlantic towards NW Beitain later today with attendant fronts crossing the Atlantic too and approaching Western Britain by midnight tonight. This follows a brief ridge of High pressure which keeps many Southern areas dry today with some showers in the North, heavy and wintry for a time. Tomorrow sees the fronts cross East over all areas with a spell of heavy rain then showers sweeping East with further flooding issues in places. Through Sunday night and Monday the weather will be very windy and showery as well as become colder with wintry showers over hills, even in the South with hail and thunder too in places. Through this time Low pressure will be slipping South over the UK to be across Southern Britain on Tuesday with rain and showers continuing with sleet or snow over the hills, chiefly in the North. Then by midweek the Low exits the South with a period of cold Easterly winds carrying wintry showers West over the UK with snow most likely over the hills and in the East.
GFS then has the second half of the week with the cold East flow dissolving away with Atlantic low pressure areas returning rather cold and changeable weather from the NW with further rain at times expected with snow over Northern hills. Later in the run Low pressure becomes even more pronounced up to the NW with bands of rain then showers sweeping East over the UK with strong winds too in places with temperatures returning to average values.
The GFS Ensembles show a spell of colder weather this week as winds swing to a NE or East quadrant briefly. This isn't shown to last long though as milder Atlantic air returns across all areas with rain and wind at times and temperatures returning to average.
UKMO today closes it's morning output with next Friday being very cold and breezy with Easterly winds carrying some wintry showers of sleet and snow across Eastern and Southern areas while Northern areas become dry and chilly with frosty nights but sunshine by day.
GEM today shows a cold and unsettled spell developing next week as Low pressure takes a much more Southerly aspect with Easterly winds the trend over the UK with rain, sleet and snow at times with some substantial falls possible in places almost anywhere but chiefly over the hills.
NAVGEM this morning also shows cold Easterly winds holding their own this morning for later this coming week with some snow and sleet showers or even longer spells of precipitation likely in the West and South at times towards next weekend.
ECM today is disappointing for those looking for cold and snowy weather as it quickly removes the Easterly feed soon after midweek in the place of a depression moving ESE into the North Sea with more rain followed by chilly and showery weather feeding down from the NW by next weekend. However, it does somewhat redress the cold balance later by suggesting cold and unstable air developing over the UK late in the run with the chance of rain, sleet and snow in the West as a front bumps up against the cold block still just about holding on to the East.
The ECM 9 and 10 Day Mean Charts shows a trend towards a UK rough the most likely in 9 and 10 days time on an axis which runs off Southern Greenland the UK to Italy. Whilst this trend is not bad for incursions from the cold continental air the pattern could do to be further west still to enable us to stand a better chance of tapping into something more meaningful.
http://www.wetterzentrale.de/pics/Reem2161.gif
http://www.wetterzentrale.de/pics/Reem2401.gif
The Jet Stream Forecast sees the strong flow crossing the Atlantic continuing to be diverted South across or to the West of Britain before turning East over southern Europe. This trend remains for a time with even the flow eventually taking a more direct route East to the South of the UK in the second half of the run.
In Summary today the weather remains very unstable and often wet as Low pressure continues to dominate proceedings over the next 4-6 days at least. Through this period it's position will change as it migrates South of the UK to bring a spell of cold East winds and possible snow in places later this week. How long will it last is hard to determine from today's output with the ECM and GFS throwing a spanner in the works as both shows progressive conditions late next week which cut off any Continental influence for a time as new Low pressure slips into the North Sea with NW winds carrying rain then wintry showers across the UK later. This pattern is also backed up quite strongly by the GFS Ensembles. However, other output is rather more compelling with UKMO, GEM and NAVGEM all looking much more sustained with regard to longevity in it's cold output. So we have a stand off between these giants of the model field and which one is right? I'm afraid more runs are needed before this one becomes any clearer so we must expect more changes good and bad in the operational outputs of all models over the coming days. My best advice will be to watch the ensembles as they may give a better idea of where we are going than any individual operational run from any model alone.
Martin G
Kilmersdon Radstock Bath Somerset