Well I daresay this morning's model output is making a fool of me; it is fairly certain that frontal systems will be bothering us this weekend and into next week, but what happens next is a bit unclear.
ECM stuck with pushing a trough to the NE of the UK, but this time not via a route right through us, so not quite as disturbed for days 6-8. Day 10 sees chilly air approaching from the NE, and temperatures would be notably below average diurnally, with a risk of widespread air frost.
GFS considered the idea on the 00z, but was a lot less progressive in bringing the trough to our NE and then far more progressive in clearing it away to allow a strong but chilly area of high pressure to affect the UK. FI gradually warms up, but not before some frosty nights.
UKMO leaves more of a trough to the SW on day 6, and that would either push warm air up from the south in combination with the Euro Ridge or allow a build of pressure near Iceland to enhance the pull of cold air south along the fear flank of the storm system moving to our NE.
GEM is like GFS but warms things up quicker as things move along more rapidly.
So there I was thinking that perhaps it would be safe to call a notable cooler interlude of 1-4 days followed by a gradual warm up, with ECM the outside option and the idea of a rapid return to warmth also of low liklihood.
...but then the GFS 06z op run started running, and it changed the game again:
http://cdn.nwstatic.co.uk/gfsimages/gfs.20140401/06/120/hgt300.png
That stretch of jet energy heading NW through Iceland wasn't there on the previous two runs.
It's a big deal, because it stops energy from running NE to Scandinavia, which then allows heights to rise there, resulting in HP instead of LP, in turn keeping the Atlantic further NW than on the 00z:
http://cdn.nwstatic.co.uk/gfsimages/gfs.20140401/06/168/h850t850eu.png
Now we have a ridge from the SW, more like GEM, which brings a more rapid return to above average temperatures. By way of balance, FI then sees HP to the west rather than east so turns really quite chilly.
So next week is totally up for grabs, which is not helpful when you're trying to anticipate the average temperature for the month
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T-Max: 30.2°C 9th Sep (...!) | T-Min: -7.1°C 22nd & 23rd Jan | Wettest Day: 25.9mm 2nd Nov | Ice Days: 1 (2nd Dec -1.3°C in freezing fog)
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