Good evening. Here is my version of the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Tuesday July 30th 2013.
The General Situation. A warm front is beginning to move North across the UK over the next 6 hrs and will of made its Way up to Scotland by tomorrow evening. It will be at it's strongest in the West but weak elsewhere with rain and drizzle for many for a time. A moist Southerly flow then follows with some warm and humid sunshine later tomorrow and for much of England and Wales on Thursday when it will become very warm or hot. Through Friday and the weekend the weather looks like gently cooling down again as a weak cold front crosses the UK Friday into Saturday. No major thundery weather is shown by any model at this juncture and a slow trend to a weekend of fresh air, sunny intervals and scattered showers is shown by most output.
GFS then shows a showery eek next week as Low pressure to the West early in the week transfers slowly East then NE to the North Sea by Friday. Showers could be locally heavy in the afternoons. Little change is shown towards the end with further showery days in slack winds and average temperatures.
The GFS Ensembles still show two hikes in temperatures in the South, one over the coming days and another next week. the weather cools off beyond that with a greater chance of rain, mostly in showery form. The North sees little benefits from these warmer phases with more unsettled conditions throughout with rain at times. The operational for Scotland was a cold outlier in the far reaches of the run.
The Jet Stream seems set in it's current latitudes for the foreseeable future flowing across the Atlantic in an undulating form and crossing the UK on a NE track.
UKMO tonight shows a very slack pressure gradient over the UK early next week with light winds as a result. With cool uppers aloft the weather could well be rather showery with slow moving and heavy showers in places, mostly during the daytime's.
GEM has a showery start to next week with shallow Low pressure close by. Later in the week a ridge from an Atlantic High moves across the North and sinks SE to the South later with attendant fine, bright and warm conditions for most, at least for a time.
NAVGEM has a more unsettled feel about it next week with a thundery Low moving up from the South and settling over the top of the UK from midweek with showers or rain at times with cooler air after a warm start to the week.
ECM shows a showery pattern too early in the week with average temperatures. Later in the week it shows a vigorous Atlantic depression moving in from the NW with bands of rain and strong winds crossing all areas to be followed by squally showers behind. With all the wind and showers needless to say it would feel a good bit cooler than recently should it evolve.
In Summary there is likely to be two fairly short bursts of summer warmth to affect Southern and Eastern Britain over the next week. The longevity of these look very short on tonight's output with a slightly firmer suggestion of more definitively cooler weather beyond a week's time with the ECM model on the extreme end of this scenario. The majority of output though holds a trough somewhere near the UK next week with light winds and slow moving showers, some heavy the most likely outcome with little suggestion that I can see of any nationwide sunny and very warm conditions at the moment.
Martin G
Kilmersdon Radstock Bath Somerset