Good morning. Here is this morning's report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Sunday January 25th 2014 taken from my website at http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm
All models show a deepening depression moving towards NW Scotland with fronts crossing quickly East across the UK with yet another spell of heavy rain and strong winds. This moves away quickly East followed by clearer and showery weather. Temperatures will fall too with showers turning wintry with snow in places, even on low ground in Southern areas with hail and thunder also possible. This showery theme will continue through tomorrow and Tuesday as the Low pressure area responsible moves only slowly South across Britain reaching Southern areas by Wednesday. As it moves to the South winds swing Easterly and enhance the chill with further wintry showers and as winds become lighter after midweek the greater incidence of night frosts look likely.
GFS then shows a new Low approaching from the West with a front moving slowly East over Britain with rain preceded by snow moving West to East over the UK towards next weekend clearing away East by Sunday with slightly milder air especially in the West. The second half of the run then shows a very inclement and wet period as further deep Low pressure areas continue to run into the UK from the Atlantic with rain and strong winds at times and temperatures returning close to normal offset by the wind.
The GFS Ensembles show good support for the somewhat colder period this week slowly giving way to more average temperature levels with rain at times through the amounts of rain stated by the operational run later is not as well supported.
UKMO closes it's run at the start of next weekend with a strong High pressure block to the East with a front moving into Western areas later on Saturday threatening rain and snow in what will be a cold and breezy day next Saturday with a strengthening SE wind.
GEM also shows this block holding firm and indeed intensifying over Scandinavia by the close of the run. Through next weekend fronts will push against the block giving a strong threat of significant snow in places before things dry up but become very cold in a strengthening Easterly flow by the end of the run.
NAVGEM too shows an active trough moving very slowly East across Western Britain with a band of significant snow edging slowly East while shearing SE into Europe later as the cold block to the NE holds firm.
ECM's operational run pushes the cold block further East with the net result being an easy win for Atlantic Low pressure next weekend bringing rain West to East over all areas, preceded by a short spell of snow in places and followed by less cold and changeable weather with rain at times, this becoming more pronounced towards the North and West as pressure rises to the South.
The ECM 9 and 10 Day Mean Charts show the chances of the Scandinavian High holding as relatively weak as the Low pressure to the NW shows a bias of allowing SW or South winds more likely to be across the UK with no doubt rain at times with a pressure rise over Southern Europe responsible for this with the most rain across Western areas.
The Jet Stream based on the GFS model Ensemble group show a preference to a strong flow across the Atlantic either crossing the UK on it's route to Southern Europe or being to the South of the UK at times.
In Summary the very interesting synoptics persist as Low pressure areas continue to run up against a cold block across NE Europe. We have GFS and ECM on the one side of the fence today pushing the block away with ease later this week and maintaining largely unsettled and sometimes wet weather across the UK in temperatures returning to more average levels after the cold week this week. On the other hand we have UKMO, GEM and NAVGEM show a much more bullish attitude to the block next weekend resulting in the very real chance of a significant snowfall somewhere across Britain dependent on the resting position of the push of Atlantic air from the West. What complicates matters today is that both the GFS and ECM ensembles support their operational runs to some degree of certainty which sets the other groups from which we have no such ensemble data to hand, more standalone in nature but despite this I feel that GFS and ECM push the block away too easily later this week and my thoughts lean more towards a UKMO, GEM or NAVGEM type solutions but of course I could be wrong..so more runs needed.
Martin G
Kilmersdon Radstock Bath Somerset