Good evening. Here is my view on the midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Wednesday August 7th 2013.
The General Situation. Over the next 5 days the weather can best be described as changeable with the emphasis always on dry and bright conditions over the short periods of rain that will affect the UK over tomorrow night and again on Sunday as troughs cross East in the otherwise benign pressure pattern. In the clearer periods on Monday some showers may affect the North in a cool NW breeze. It will feel pleasantly warm in the South at times with Saturday looking particularly pleasant while Monday too though pleasant could feel rather fresher.
GFS then shows the rest of next week with High pressure building across the South with dry and pleasantly warm conditions developing with good sunny spells while the North maintain somewhat less settled for a longer while into the week. Nevertheless by the weekend Low pressure regains control to the North pushing troughs East across all areas through that weekend and into the new week with rain and showers in all areas at times. Then at the end of the run High pressure builds solidly just to the East of the UK with increasingly very warm or hot conditions developing for all from the South.
The GFS Ensembles show the operational was an outlier at the end unfortunately with many members preferring to keep very average conditions going over the UK with rain at times, chiefly in the North while the South sees the best of the drier and sunnier breaks in the Nationally average temperatures.
The Jet Stream tonight continues to blow across the Atlantic close to or over the British Isles where it remains for the reliable future.
UKMO tonight shows High pressure building into Southern Britain from the SW with a spell of fine and warm weather developing for Southern areas at least by the middle of the week though how long fine conditions last is open to debate tonight.
GEM keeps the theme of High pressure remaining reasonably close to the South through much of next week before any meaningful attack of cool and unsettled weather makes any inroads beyond Northern Britain.
NAVGEM is in full agreement of the above prognosis too with fine weather in the South throughout the second half of it's run as High pressure remains just to the South of the UK. The North though will see less certain events with more of a Westerly breeze accentuating the risk of rain at times here.
ECM keeps to it's plan of this morning with High pressure held at arms length to the SW of the UK so that by the middle of next week the cool NW flow of the early days are replaced by a broad Westerly flow with troughs crossing East delivering rain or showers from midweek on in technically rather cool conditions but I'm sure that in between the rain bands it would feel pleasant enough.
In Summary tonight it's a pity that ECM isn't playing ball tonight as it's the fly in the ointment of an otherwise acceptable night's output. All models (UKMO included) except ECM have High pressure coming close to the South of the UK with the promise of some decent fine weather with sunny spells and warm conditions next week. ECM though has been resolute in maintaining it's stance on the more mobile and unsettled weather next week and must not be discounted despite it's isolation. we can only hope that it backs off soon to take a more UKMO type route.
Martin G
Kilmersdon Radstock Bath Somerset