Good evening. Here is the report on the 12 midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for tonight Tuesday July 23rd 2013.
All models maintain the fairly gentle Southerly flow over the UK with fine and dry conditions alternating with thundery showers or storms at times almost anywhere but as always never evenly distributed over the UK with some missing out on these entirely and perhaps more concentrated towards the North and East. A further surge of warmth at the weekend could lift the SE into the hot category for a while again with the risk of a further thundery outbreak moving NE across these SE areas. Then as we start next week some differences between the models begin to emerge.
GFS tonight shows next week as a further potentially thundery week as cooler Atlantic air struggles to breakthrough the hot plume over western Europe. This means through the week the weather is shown to stay very much on the warm side with pulses of thundery rain and thunderstorms continuing to blight the UK from time to time as successive injections of cooler air hits the buffers over the UK. It's not until well into the latter stages of the run that cooler air does win through only to be replaced by a renewed surge of High pressure extending NE from the Azores at the end of the run bringing what looks like a further spell of sunny and very warm summer weather.
The GFS Ensembles show a spell of showery weather over the next few weeks. There will be a lot of warm weather in association with this weather type and as a result the rainfall where it occurs will potentially be thundery as winds are maintained from a Southerly source. Towards the end of the run there is some support for a rebuild of High pressure from the SW towards the UK, at least to the South.
The Jet Stream continues to undulate over the Atlantic dipping South to the West before returning NE across the UK and on into Northern Europe around the hot plume over Western Europe.
GEM shows Low pressure to the West and North of the UK over the coming week to 10 days. There will be some rain at times with the North and West possibly seeing the most risk though the SE closest to hot conditions on the continent could see some thundery outbreaks at times too.
NAVGEM continues to show the showery theme up to and including the weekend before a more definitive cool off in fresher Westerly winds with rain at times arrive early next week.
ECM tonight shows another hot plume pushing North through England and Wales at the weekend with another surge of heat and thunderstorms likely for many areas transferring North. The South will then become cooler and fresher again with sunshine and scattered showers by the start of the new week. It isn't long before heat rebuilds next week over the South and East with further potential for thundery outbreaks to interrupt the otherwise continuing warm and sometimes sunny conditions here while the North stays somewhat cooler and fresher with occasional rain and nearer to average temperatures possibly extending to all areas later.
In Summary the weather looks like staying relatively warm now for the reliable timeframe. With hot weather maintained on the Continent and repeated attempts by Atlantic fronts to nudge into this hot block there is plenty of chance created for occasional bursts of thundery weather across the UK moving South to North, probably more pronounced towards the South and East with brief flirtations with rather cooler air at times behind. There are still some signs of more definitively cooler weather for all areas in the mid to long term but there has been a definite swing towards the hotter air over Europe to influence at least some parts of the UK for quite a while yet with nowhere seeing any temperatures below average in the coming 10-14 days with the likelihood of well above average temperatures featuring very strongly in tonight's output.
Martin G
Kilmersdon Radstock Bath Somerset