Good morning. Here is the morning report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Saturday August 17th 2013.
All models show an active Low pressure to the NW of the British Isles moving East to the North of Scotland carrying a system of troughs East across the UK today with wind and rain. A more straightforward Westerly flow is shown tomorrow with sunshine and showers for all. Pressure will be rising quickly across the South later in the day with High pressure moving in close to Southern and Eastern areas through the early days of next week with the North and West remaining more changeable up until midweek with rain at times.
GFS then shows fine and warm weather extending to all areas from midweek as high pressure migrates North. Late in the week and weekend some thundery showers may develop towards the South as some thundery Low pressure edges up from the South. Through the remainder of the run warm weather is shown to continue for a time before more changeable conditions develop from Low pressure areas close to the SW towards the end of the run.
The GFS Ensembles show a sustained spell of warm and largely dry weather is pretty much nailed on now especially in the south and East. As always there is a slow fall off in temperatures towards the end of the run as natural variability and more uncertainty is likely at that range.
The Jet Stream forecast continues to project the flow moving North next week in response to high pressure over or near the UK. It does then become weak and indecisive in location later as slacker pressure patterns take hold.
UKMO for soon after midweek shows High pressure just off Western Norway with a SE flow across the UK with very warm and sunny weather likely. Some thundery rain is getting close to the far SW by the end of the week.
GEM too shows High pressure close to Northern Britain with sunny spells for all and very warm conditions too. As the other models thundery Low's lie to the South or SW later with an increasing risk of thundery showers here by the end of the week and into the weekend.
NAVGEM is the same with several warm and sunny days later next week giving way to more thundery conditions developing across Southern Britain, certainly by the weekend.
ECM completes the set with High pressure to the north late next week with a slack easterly flow over the UK with Low pressure down to the SW. There will be plenty of fine and very warm weather to be enjoyed though the risk of thundery showers is present for the South next weekend.
In Summary there is a lot of uniformity between the models today with all models promoting a period of warm, sunny and settled weather next week, nationally from midweek. In addition they all also show that the weather may turn rather humid and thundery later next week and weekend with Southern areas at risk of thundery showers though from this morning's output nothing widespread looks likely and most likely none at all away from Southern England. With a light Continental flow next week some very warm temperatures are likely probably highest in the sheltered West and in the South generally.
Originally Posted by: GIBBY