Good morning everyone. Here is today's look at the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for Tuesday Noveember 13th 2013.
All models show that the weather will remain changeable between now and the start of next week as High pressure holds to the SW of Britain. Occasional cold fronts will cross SE, one such one overnight tonight and another on Sunday with rain for a time for all. Through this 5 day period temperatures will be close to normal but rather chilly at times in the North. Sunshine after today and tomorrow will be at a premium as cloudier skies from the Eastern Atlantic invade the UK over Friday and Saturday holding temperatures back somewhat even in the South at the weekend.
GFS then shows a spell of colder and unsettled conditions early next week with spells of rain with sleet or snow over the hills and the risk of overnight frosts as skies clear overnight. However, this situation doesn't last long as High pressure reverts to a position SW of the UK allowing milder Atlantic weather to return. As a result the rest of the run becomes a case of changeable and sometimes wet conditions with wind, rain and showers occurring for all areas periodically with temperatures close to average.
UKMO shows Low pressure up to the NE with a rather cold WNW flow with showers and sunny spells following a band of rain SE through the day on Tuesday. Snowfall will be reserved for the higher ground of the North.
GEM shows a more sustained cold period developing from early next week with Low pressure close to the East giving a cold Northerly airflow. A ridge then develops across the UK briefly with another surge of cold Northerlies as Low pressure deepens to the East of Britain at the end of the run. Rain or wintry showers would be the order of the day through the period with temperatures below average and frost developing at night as the ridge towards the end of the week allow skies to clear.
NAVGEM maintains it's quest of dropping Low pressure down to the West of Britain early next week with wet and windy weather with temperatures on the low side of average without ever being desperately cold. As a result of this the weather will be very unsettled and often wet in cyclonic winds. Snow would reserved mostly for the high ground of Scotland.
ECM today shows deep Low pressure migrating SE across the North Sea to SE Europe next week as pressure builds from the NW later. The weather will become cold and unsettled next week with rain or sleet at times and snow over all higher ground in a blustery and chilly wind from the North. Late in the run drier conditions move down from the NW with cold and frosty weather developing later with freezing fog problems likely to become an issue.
The GFS Ensembles clearly show a trend towards a rather colder and unsettled period next week. Things never become desperately cold however and any snowfall will be reserved for the hills of the North for the most part. The north look like it may become somewhat less chilly later while the SE appear to hang on to the rather chilly conditions for longer though at the outer limits of the run there is much spread between the members as normal.
The Jet Stream shows the flow ridging North high over the Atlantic at the moment and away across Northern Europe. Later in the weekend and next week it dives South across the UK and then some output shows it setting up a position to the South and West of the UK by the end of next week, this mostly shown by ECM.
In Summary today the weather is now more or less guaranteed to turn rather colder next week. With Low pressure close to the East and a fresh Northerly airflow it will feel much colder than anything we have experienced so far this season. There will be showers or longer spells of rain too moving through in the flow with some snowfall on all Northern hills and mountains with high level routes subject to some disruption. Longer term it looks likely that a change to more settled conditions from High pressure to the NW, (ECM) West, (GEM) or SW (GFS) is likely and depending on which solution is right will determine conditions over the UK. Any ridging from the NW will mean cold, frosty and foggy conditions being possible while from the SW would allow milder Atlantic winds to topple over the UK to return milder and cloudy conditions with occasional rain.
Transcript taken from:-http://www.norton-ra...is(2859336).htm
Martin G
Kilmersdon Radstock Bath Somerset