Good morning folks. Here is the what I like to think is the unbiased and 'say it as i see it' morning rundown of the midnight outputs of the big computer models for today Wednesday July 31st 2013.
The General Situation. All model show a warm front moving steadily North across the UK today and tonight carrying a band of rain and drizzle North across the UK and introducing some warm and humid air to England and Wales later. The front will reach Scotland tomorrow with rain here while England and Wales see very warm or even hot conditions briefly in the SE as winds back Southerly. On Friday a weak cold front crosses East across the UK carrying a few showers and introducing cooler and fresher air behind reaching the far SE late on Friday. The near Continent will see some thunderstorms from this but they look unlikely to reach the mainland of SE Britain. The weekend is then shown by most output to see SW winds and scattered showers with Saturday seeing most showers while Sunday looks mostly dry in the South and pleasantly warm conditions and less humid too than of late.
GFS then steadily keeps the UK under slack pressure early next week with sunshine and scattered showers with average temperatures later. Through midweek pressure falls over the near Continent with areas of potentially thundery rain affecting South and East England later with the driest weather to be found in the North and West under a ridge. By next weekend the ridge collapses over the UK as a deep Atlantic depression moves in from the NW with a spell of rain and fresh winds for all leading us into a relatively cool and showery phase then out to the end of the run.
The GFS Ensembles have greatly modified the effects of the second warm up indicated last night for next week. Today we see the weather cool off at the weekend and a relatively average period of temperatures or slightly above at times in the South. In the North the weather looks quite unsettled from next week and the effects of this extend to the South too at times as Low pressure trundles East across Northern Britain.
The Jet Stream today shows our problem with maintaining fine and warm conditions over the UK in the upcoming period as it is now based too far South over the Atlantic steaming the flow over the UK NE from Biscay and eventually on a flat West to East course across the UK from the middle of next week.
UKMO this morning shows a showery trough edging East over the UK early next week changing the SW flow to a NW one albeit light. the showers could be heavy through the daytime with hail and thunder a possibility in temperatures close to average.
GEM looks very changeable today with a small Low crossing NE early next week with rain at times. A ridge then follows from the West with a 24 hour or so window of fine and bright weather before low pressure from the NW delivers a spell of rain for all followed by showers by the end of next week. Temperatures look like they would be close to average overall.
NAVGEM keeps slack pressure over the UK early next week though it is biased towards Low pressure as a shallow cool pool lies over the UK promoting showers in most places through the daytime's.
ECM shows Low pressure crossing slowly NE across the UK early next week and away to the NE by midweek. A spell of rain on Monday would be followed by breezy and showery conditions midweek before further Low pressure from the NW ensures the weather stays unsettled and cooler to end the week too with rain at times in winds from a West or eventually NW point.
In Summary it is beginning to look like it could become more generally cooler and unsettled next week. A lot of the charts show just shallow Low pressure near the UK with the familiar showery mix when some people avoid them and stay in relatively dry and quite warm conditions while others get a lot and feel cool at the same time. However, there are some increasingly popular signs of bringing in more active weather systems from the NW later next week which would turn the weather more widely unsettled, breezy and cooler with some longer spells of rain as well as showers on occasions for all. There doesn't seem too much chance of warm and settled conditions returning on a widespread basis anytime soon from today's output given that the Jet Stream has now flown South and is programmed to remain near the 50 deg N line for some considerable time keeping it on a collision course over the South of the UK.
Originally Posted by: GIBBY