Good evening. Here is the report on the 12 midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Monday August 19th 2013.
All models show the rest of the working week as fairly nailed on but everything thereafter far from. For the South and East the rest of the working week will be mainly dry and increasingly warm with sunny spells, these chiefly tomorrow, Thursday and Friday. The North and West of Scotland and Northern Ireland will see some rain from a depression and associated fronts moving towards Scotland over the next 24 hours or so. The remains of the cold front then crosses slowly SE across North and West Wales as well as SW England on Wednesday with a little rain possible.
GFS then shows a new Low filling but moving SE close to SW Britain at the weekend allowing some showery rain to affect Southern and SW England at the weekend. The shower risk remains on Bank Holiday Monday but with a good deal of fine and bright weather too. The latter part of the run paints a picture of High pressure to the SW and a NW flow over the UK with plenty of fine and dry weather with average temperatures before a trend towards more changeable conditions is shown towards the end of the run as winds back West for a time.
The GFS Ensembles show a more changeable pattern for the South after the 24th. The operational was a warm member of the pack from the breakdown at the weekend with many other members suggesting more average uppers in a more mobile westerly regime.
The Jet Stream shows the flow moving North away from the UK for a while with a returning flow South over the UK early next week. The flow energizes quite a lot later next week as it positions West to East over the Atlantic and over the UK.
UKMO tonight shows a trough having moved to the East of the UK on Sunday bringing a drier period for the second half of the weekend with just scattered showers in temperatures slowly cooling to more average levels given the Northerly flow.
GEM also shows a weakened breakdown with a showery trough crossing East over the weekend followed by a cooler NW flow with a lot of dry weather across the UK with any rain or showers restricted for the most art to more Northern parts.
NAVGEM shows a more definitive unsettled weekend in the South as a small Low slips SE across the South and into Northern France with thundery rain or showers likely. the north would see the best of the weather with few if any showers here. The final days of the run signify a cooler Northerly flow with showers in Eastern Counties of both England and Scotland with the best conditions in the West.
ECM tonight shows a showery start to the weekend as a front moves East over the UK. The second part of the weekend shows a better outlook with drier and cooler conditions having arrived from the West with High pressure building solidly over the UK by midweek with very warm and sunny weather developing everywhere.
In Summary it is looking increasingly likely that the weekend may not be a write off as was looking possible from recent output. Instead it looks like a showery trough will slide East across the UK through the first few days of the weekend before pressure rises again in time for the Bank Holiday with a reasonable prospect again for next week as the possibility of another ridge from the Azores looks feasible to the extreme from ECM with a large High pressure area located over the UK with very warm and sunny weather by midweek or soon after.
Originally Posted by: Hungry Tiger