Good evening folks. Here's how I see the midday outputs of GFS, UKMO, GEM, NAVGEM and ECM and what they mean for us down on the surface over the next week or two.
All models show a weak cold front moving South across Central areas overnight with a band of outbreaks of rain moving South to reach South Wales and the Midlands by morning. The North will see clearer conditions behind the rain with a frost in places and a few wintry showers over the far North. Through tomorrow the rain progresses through the South while another front approaches the North later. Clearer conditions will give the South more sunshine later in the day while Northern areas become cloudier and breezier later. Through tomorrow night and Thursday a rapidly deepening depression moves East then SE to the North and NE of Britain with gale or severe gale force winds over Northern areas and with a short spell of rain moving quickly SE down over all areas through the day. Very cold air will follow with snow showers in the North and East while Southern and Western areas stay dry, breezy and cold. Then after a frost on Friday night High pressure slips SE over Southern Britain allowing milder air and cloudy conditions from the North Atlantic to filter across and down over the UK through the weekend.
GFS then shows the rest of the run with the UK under mild SW or SSW winds with Northern and Western areas under risk of rain at times in blustery winds. More Southern and Eastern areas stay largely dry with rather cloudy conditions prevailing and temperatures possibly mild if surface winds stay sufficiently breezy to bring milder uppers down from above to the surface.
UKMO tonight shows High pressure over much of France and the Meditteranean Sea with a Westerly flow over Northern Britain with relatively mild and cloudy conditions here. Over Southern Britain winds will be quite light with a lot of cloud at times but with some drier and clearer skies at times too leading to frost and fog patches night and morning with chilly and grey conditions prevailing at other times.
GEM shows High pressure to the SE building strongly through next week with mild Atlantic winds affecting the North and West while Southern and Eastern areas stay dry and though rather cloudy at times areas of mist, fog and frost under any clearances in the cloud could give some more rather chilly anticyclonic gloom type days down here.
NAVGEM follows the trend of the others with a moist SW flow over the North and West carrying cloud and mild weather across these areas. In the South and East it may well be that we maintain somewhat colder conditions with some frost and fog patches should cloud breaks occur overnight.
ECM shows a large High pressure area over France later next week which will maintain mostly fine and settled conditions across many areas. It will not be particularly mild early in the week away from the NW but it does look under the light to moderste WSW flow shown on Day 10 that mild if cloudy conditions look likely for all though with very little rainfall anywhere.
The GFS Ensembles show a cold snap over the coming few days before things turn less cold and benign once more as High pressure to the SE wafts Southerly winds up across the UK. Rainfall is shown only towards the latter part of the run for the South from some members with amounts small for all.
The ECM 12 noon ensembles also paint a relatively mild scenario at least aloft with High pressure to the SE of the UK. To obtain cold from these we need an inversion which often means cloudy, grey and rather cold conditions in very light winds. If however, the winds are somewhat stronger at the surface some of those warmer uppers could translate towards the surface though conversely frost becomes an issue at night should drier continental winds make landfall over the South.
The Jet Stream shows the flow to the NW turning SE down the North Sea briefly over the next 72 hours before the flow quickly resets in a NE direction over the Atlantic to the NW of the British Isles and on over Northern Scandinavia.
In Summary tonight the cold snap is almost here and still shows a 'blink and a miss it' affair away from Northern and Eastern parts where severe gales and occasional snowfall could be quite noteworthy for a while. However, this is the only noteworthy weather conditions to come out of the 12 noon models tonight. All of them show High pressure moving in close to Suthern Britain at the weekend and down to the SE from the start of next week setting up a South or SW flow over the UK. With the proximity of High pressure so close to the SE at times then cloudy and dry weather will probably sum up the weather through most of next week and probably beyond with little or no rain away from the far NW at times. Temperatures will be on the warm side of average over Northern and Western Britain under a maritime SW'ly while Southern and Eastern areas possibly too sharing some of this milder air remain always at risk from incursions of Continental air bringing colder air in from Europe at times with frost and fog issues should it occur. All in all though it looks very likely that it is going to be sometime before our UK weather resembles anything like real Winter weather with most farmers, growers, travellers and the like able to carry out their outside duties and travels unhindered.
Martin G
Kilmersdon Radstock Bath Somerset