Good evening. Here is the report on the 12 midday output from GFS, UKMO, GEM, NAVGEM and ECM for today Monday September 9th 2013.
All models show Low pressure to the East of the British Isles giving cold NW or Northerly winds down across the UK. Many areas will be dry from now but Eastern Coastal Counties will be cloudy with spells of rain and a very cold day for September tomorrow. This eases away East along with the Low pressure on Wednesday as a ridge topples SE across the UK. Following hard on it's heels is a series of fronts which bring rain SE across all areas later in the day with Thursday seeing unsettled and cloudy conditions predominating with further rain at times gradually clearing from the North on Friday but slow to do so in the South. Over the weekend the winds freshen markedly in the North on Saturday and more generally on Sunday as Low pressure winds up to the North of the UK.
GFS then shows early next week as a very turbulent spell with gale or severe gale force winds over Scotland and NE coastal counties as a vicious Low pressure slides past Eastern Scotland. As well as high winds for all rain would occur too, heavy for a time before being chased away by cold NW winds and showers by midweek. The Low pressure responsible then moves away North to be followed by a very changeable and Autumnal remainder of the run with spells of strong winds and rain alternating with cool and showery weather with the South too seeing some appreciable rain at times.
The GFS Ensembles tonight show considerable spread from the end of the week with most members showing very changeable but not always wet conditions with widely fluctuating temperatures from day to day and member to member.
The Jet Stream is showing signs of getting into Autumn now with a much stronger flow at times than recently. It's position remains variable through this wee, mostly tumbling down over the UK from the NW. Later in the week and next week the flow strengthens on a strong West to East motion across Scotland or England.
UKMO tonight shows a deep Low winding itself up to the North of Scotland next Sunday with strengthening winds and rain sweeping East across most areas by the start of next week.
GEM tonight also shows the UK experiencing a swipe from a deep Low pressure travelling ESE close to NE Scotland late in the weekend clearing away East as we move into next week with a cool and showery NW flow blowing ahead of a temporary looking midweek ridge.
NAVGEM too shows the weekend Low but further North and affecting mostly just the north with wind and rain while the South though cloudy and breezy would probably see just a short spell of rain as the cold front weakens as it moves SE in the wake of the blow.
ECM tonight harmlessly takes the Low on a track well North of the UK with some affects to the North in the shape of windy weather with a spells of rain. Southern areas would maintain largely benign conditions with just short bursts of showery rain as weakening fronts pass by in association with that Low to the North. Late in the run and High pressure arrives back over the UK from the West with fine, dry and Autumnal conditions prevalent for all.
In Summary the weather remains less than certain for the period later in the week and the weekend. In the short term troughs moving down from the NW will deliver a lot of cloud for all this week with some rain at times, chiefly Wednesday and Friday in the South. Thereafter we have a variety of options shown ranging from raging gales, heavy rain and cool conditions to more mundane conditions when there will be mostly cloudy skies with just patchy outbreaks of rain, less wind and temperatures close to average. The next instalment tomorrow morning will probably give us some more variable output maintaining the poor run that the models have had of late of predicting things more than 5 days out in a unified manner.
Originally Posted by: GIBBY