Hi everyone. Here is the report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Saturday November 16th 2013.
All models show agreement now on the pattern of events up to the middle of next week. A slack airflow over the UK will persist today with cloud invading the still cold and frosty SE later today. Some light rain in the NW intensifies later as a cold front sinks slowly South over the next 24-48hrs. A band of rain will accompany it before colder clearer weather follows slowly behind reaching Southern England later on Monday. With a cold NW airflow then showers will be driven into Northern and Western areas and will turn to snow on all high ground and some lower ground too at times. Southern and Eastern England will see relatively few showers and will see some cold sunshine through these days.
GFS then shows the post midweek period as becoming dry and frosty over the UK with mist and fog problems night and morning as High pressure builds across from the West. Later in the run Southern and Western areas are shown to turn more unsettled as a chilly SE flow develops with pressure falling to the SW sending rain bearing troughs NE into Southern and Western Britain. Northern and Eastern areas look like staying predominently dry and rather chilly throughout the run with this weather type extending back over the South too at the end of the run.
UKMO closes it's run with High pressure sliding SE across the UK with settled and dry weather but pretty cold conditions at the surface and overnight frost and freezing fog could become a big problem for commuters towards the end of next week and may fail to clear by day in places.
GEM this morning shows a progression towards mostly dry and fine weather following the cold weather early in the week with wintry showers. With High pressure just to the West a lot of rather cloudy and benign coditions look likely with temperatures just below average but with some frost at night behind weak cold fronts passing South at times when skies clear.
NAVGEM shows High pressure building across more Northern locations later next week but the South maintains a very cold and blustery ENE flow with rain and sleet at times and snow on the hills. Some frost and freezing fog patches will develop over the cold and less windy North late on in the run.
ECM brings high pressure across from the West midweek snubbing out the Northerly flow and frost and fog in calm conditions look likely for a day or two. Pressure falls to the West and later the South with a chilly SE then NE wind across the South with rain at times later with even a little sleet over the hills while Northern areas stay largely dry and rather cold.
The GFS Ensembles show a short cold snap before conditions slowly recover to very much average conditions for late November. A period of stagnant High pressure seems likely with frost and fog at the surface issues late next week before the mean for the pack suggests the Atlantic cranking up later with rain and strong winds crossing East over the Uk on occasions late in the run.
The Jet Stream shows the flow way North of the UK currently before it turns sharply South early next week. This northern arm then detaches from a weaker Southern arm and continues to blow strongly East at high latitudes later next week suggesting UK High pressure. It does break down later and resets closer to the UK later in the run.
In Summary the Northerly of next week still looks like there is an opprtunity of a day or two when snowfall could be seen by some parts of the UK chiefly in the North and West and over the hills. Thereafter High pressure looks likely to build in from the West or NW with a chilly and raw day or two possible in the South on a ENE flow around midweek. It looks likely the High will migrate East then into Europe and maintain a ridge West or NW over Northern Britain. This sets up a SE flow over the South and with falling pressure down to the SW rain would make progress into these parts with time to give dull and uninspiring late November conditions down here with some rain at times while Northern locations stay largely dry and bright if on the chilly side. most output does suggest High pressure in the Scandinavian region later in the run and this could be the catalyst for more blocking conditions for the UK which could in time result in further cold outbreaks developing as we drift deeper towards Winter official from December 1st. For now though all of the above suggests typical November weather for the UK.
Transcript taken from:-http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm
Originally Posted by: Andy Woodcock