Good evening. Here is the report on the midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Monday November 18th 2013.
All models show a change under way to colder conditions. A showery NW flow will cover the UK tonight and tomorrow followed by a deepening Low pressure moving South down the North Sea on Wednesday with a spell of rain and strong winds with snow on the highest ground briefly. Following in behind will be a return to colder and brighter weather with wintry showers dying out by the weekend as High pressure builds across the UK with frost and patchy fog overnight.
GFS shows High pressure dominant over the UK or just to the West for most of the rest of the run with fine and dry weather with relatively light winds. After a cold start temperatures would gradually rise as warmer uppers come into the mix. However, this is dependant on the amount of fog is around and how quick it clears each day. Late in the run a brief and cold surge affects the East before High pressure returns back over the UK.
UKMO starts next week with High pressure anchored over the UK with fine and dry conditions but cold. Frost and fog will be the main problems in the weather over the period and daytime rather cold levels will be amplified by any persistent fog patches which fail to clear by day.
GEM too tonight shows High pressure well anchored over the UK through the weekend and through much of next week with cold and clear conditions though fog and frost problems will become widespread transport issues through the period.
NAVGEM tonight holds High pressure slightly further North over Scotland with something of an Easterly flow maintained over the South of England and Wales. Northern and Central areas will be dry and fine with frost and fog while Southern areas too are likely to see frost with abit more breeze fog may be more patchy.
ECM shows High pressure too across many parts of the UK at the weekend with the trend to drift it towards Scandinavia as we move through next week. This maintains cold weather across the UK with a stronger Easterly flow over the South making it feel very raw. Frosts will remain widespread but any fog is more likely across Northern areas where winds remain lighter.
The GFS Ensembles show uppers quite low to begin with before a slow recovery to average levels from the end of this week. However, with High pressure generally in control from many members surface conditions may be a good deal colder with frost and fog at surface level quite widespread at times.
The Jet Stream shows the flow moving South across the UK for much of this week before it sets up a clockwise circulation around the UK which would indicate High pressure close to the UK into next week.
In Summary the weather looks like becoming quite settled under High pressure as this weeks rather cold and changeable conditions give way to fine but still cold weather with frost and fog the main features to contend with. Some wintriness may accompany the changeable theme through this week, mostly over the hills. ECM and to a lesser degree NAVGEM shows High pressure held a little further North allowing an Easterly flow across the South next week but other than the risk of the odd wintry shower near the SE coast should ECM verify it looks like a prolonged dry spell for many across the UK.
Transcript taken from:-http://www.norton-ra...is(2859336).htm
Martin G
Kilmersdon Radstock Bath Somerset