Good morning. Here is the report on the midnight outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Friday August 30th 2013.
All models show a series of weak fronts crossing SE over the UK today and tonight, the last of which brings clearer, cooler and fresher weather to all areas before tomorrow morning. The weekend will then see pressure rising again with the cool NW flow for both Saturday and Sunday being snuffed out by Monday. bright and sunny if cooler conditions will affect all for the weekend with cool and dewy night's Monday and Tuesday are both shown to be bright and dry and altogether warmer again in the South while the North clouds over with time with an increase of SW wind and a little rain late Tuesday.
The Fax Charts appear to be having none of the breakdown anytime soon next week as the High building over the South at the weekend and start to next week looks very reluctant to leave the South on the 120hr chart released last night with no more than a glancing blow from troughs over the north by midweek.
GFS then shows more unsettled conditions spreading East across the UK later next week with some rain at times for all in average temperatures. Fronts then continue to affect the UK at times until the start of the second week and rather longer in the North before High pressure builds over the UK from the South and West with fine and dry weather dominant with mist and fog at night at the end of the run.
The GFS Ensembles continue the theme as before with a cool weekend and then a warmer couple of days before a period of average uppers or thereabouts are accompanied by occasional rainfall even in the South. The operational was a warm outlier at the end of the run but with plenty of spread I wouldn't discount it.
The Jet Stream prediction is based on the GFS output and with High pressure based over the UK in the latter part of the run the flow remains located North of the UK for much of next week. However, the general consensus from other output is to bring it somewhat further South though not alarmingly so with the main thrust of it crossing near the North of the UK next week.
UKMO today shows a trough of low pressure crossing East over the UK next Thursday with some showery rain for all for a time, heaviest in the North. I would suggest a ridge of High pressure would possibly follow at the end of the week with things drying out again.
GEM shows a similar trough crossing East after midweek with High pressure building back over the North from the Atlantic by the weekend while low pressure develops near the SE with a cool North then NE flow bringing some rain or showers for these areas in cool weather while for a change the North and West see the driest and brightest conditions though none too warm.
NAVGEM today shows a weakening trough cross east too midweek before pressure begins building again from the SW towards the end of the run with the rain petering out in the East as dry weather spreads back in by the weekend from the South and West.
ECM is this morning somewhat similar to GEM bringing a trough across midweek which is followed by a cut off depression which locates near SW Britain at the end of the run with rain or showers likely in the South from midweek. The North too would see rain at times before High pressure ridges across from the Atlantic here drying things up and allowing some sunny spells.
In Summary there is a lot of disagreement on the events of weather beyond the still broadly agreed pattern of a trough of Low pressure bringing some rain across the UK from the West around midweek. Then things diverge between the models with no model showing a full blooded breakdown that was being indicated yesterday. Instead we have a cocktail of options which range from cut off lows to the South and further High pressure building from the SW yet again. So it looks like we will have to wait until nearer the events before a clear pattern is drawn but imo I wouldn't bet against High pressure to the SW continuing to show further dominance over the UK weather next week and beyond too, being that it has played such a major influence over the nation's weather this Summer.
Martin G
Kilmersdon Radstock Bath Somerset