Hi everyone. Here is the morning look through the outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Thursday August 22nd 2013.
All models show a cold front clearing East out of SE England this morning leaving a warm airflow over the Southern half of the UK with a slight Easterly or variable drift to the wind flow over the UK. After early rain, apart from a few afternoon showers the weather will be dry today. Tomorrow a new cold front is shown moving into the West and this crosses slowly East over the following 24 hrs developing a small but slow moving Low centre close to SE England over the weekend which is shown to recede only slowly away East by Bank Holiday Monday. In the North a ridge of High pressure develops behind the front on Saturday with a lot of dry and bright weather for the North and NW over the holiday weekend while showers, some heavy are likely elsewhere.
GFS then shows a ridge of high pressure across the UK next week with fine, bright and reasonably warm weather for most. However, there remains a weakness close to the SE where the occasional shower remains possible until the weekend. The ridge then extends to all areas and strengthens in week 2 with a large High centre locating to the West and extending across the UK late in the run it what would be a very dry and settled latter half to it's output this morning for all of the UK.
The GFS Ensembles show the operational as one of the warmer members with quite tight clustering in Southern locations through the run today, all hogging the long term average level for most of the run. There are few warm members shown but a few chilly ones showing up while northern locations see a lot more spread in a changeable weather pattern up here. Rainfall in the South remains programmed to be below average.
The Jet Stream today is shown to be well North of the UK at times in the next two weeks but probably too high to the North over the Atlantic with something of a returning arm South from Iceland close to the UK at times especially later meaning the warmest air in association with High pressure will be away from the UK.
UKMO today shows a slack NW flow over the UK by midweek next week in association with a broad ridge across the UK from High pressure just to the SW. The weather would be largely dry and benign with sunny spells and comfortably warm conditions for most away from cooler northern and Northeastern coasts.
GEM shows a strong ridge across Britain early next week which then develops into a closed cell of strong high pressure close to Western Britain late in it's run with a light northerly drift over the UK. Dry weather would be almost universal away from a few showers in the North early in the week. Thereafter a benign and quiet spell of anticyclonic type early Autumn weather would ensue with reasonably warm and bright days but cool and misty night could develop inland too.
NAVGEM has the scenario of losing the Low pressure away to the SE only slowly next week with some showers for a time down there while pressure will be High elsewhere with fine and dry weather which extends to all areas late in the run with fine and warm conditions with cool and misty nights as High pressure anchors over the UK.
ECM shows a slack Northerly flow over the UK for much of next week with some showers in the East for a time before it too brings High pressure across from the West over Northern Britain with a fine and settled spell developing for all with warm sunny spells by day and some cool and misty nights.
In Summary today it's a High pressure based pattern which looks set to rule the roost over what's left of our meteorological Summer and the beginning of Autumn. Nearly all models support an evolution which suggests High pressure sitting over or close to the UK later next week and beyond which would bring a period of fine and settled weather. All models seem to wish to keep the High just to the West of the UK which would bring a cooler injection of air into the mix at times holding temperatures towards the rather warm instead of very warm category but nevertheless the Farmers and Growers will welcome this news this morning for the continuing harvesting season. There is just one small caveat, this synoptic setup could deliver some quite chilly nights and now that the nights are approaching parity with daytime in length there is increased time for some cool nights to develop with a much increased risk of mist and fog in places, clearing readily in the mornings though.
Originally Posted by: GIBBY