Super outlook, can't wait. 

A breakdown of the fine warm spell looks to be the form horse now at about 168h. After that the models are all over the place so its anyone's guess.

It certainly looks as though unsettled will lead the way again. Valuable lesson really. If the model shows unsettled, it is far more likely to verify than if it shows hot and dry. 

10-day forecast less warm than last time I looked - nothing really cold but the 'yellows' are staying well south http://www.wxmaps.org/pix/temp4 Rather more rain in week 2, and the way this is concentrated over the land are of the UK hints at convective origin http://www.wxmaps.org/pix/prec4 

Jetstream resuming W-E across or close to N of UK  to Tue 19th then developing a big loop with the active bit running S-N across UK before resuming W-E for week beginning Sun 24th but this time across or close to S of UK.

GFS shows ridge of HP as expected across UK until Tue 19th and then moving off to be centred over Norway Sat 23rd May.  The intense local depression which GFS has been touting at that time is now replaced by a more ordinary and slacker one moving across UK 1000 mb Mon 25th (relates to the convective stuff above?) but stalls over the N Sea so light northerlies until Sun 31st.

GEFS shows a mild/warm spell Sun 17th - Sat 23rd then many runs cooler to Fri 29th and a hint of an uptick at the end. Not much change there but rainfall pattern which starts around the 22nd/23rd is much spikier than previously.

ECM is still yesterday's 12z at time of posting but looks as if it's moving the same way as GFS. Both BBC's WeatHer for the Week Ahead and ECM do show the LP forecast by GFS for the 25th as sitting out to the west in a position to move in at that time

EDIT @ 1020 Now that today's ECM is out, it's clear that ECM is having nothing to do with LP anywhere near the UK. It moves that Atlantic LP off to the north and replaces it with HP to the E of the UK with notably warm air coming up from the S. So big disagreement between the two main models after weekend of the 23rd

Yes ECM is a cracker again but it's still anyone's guess beyond a week from now. hopefully we get lucky.

I can't help but think that after such a dry spring we're in for a washout summer. Hope I'm wrong though.

I think that's a bit OTT. I dont think end of May is settled yet, hench the different options. As for much more unsettled - I am not seeing that either. 

Oh, they really can

12z so far GEM and UKMO good, GFS and ICON crap. 

GFS 12z op is a significant outlier, check out the MSLP for confirmation of that. 

Regardless of what next weekend has in store, we have a nice warm spell to enjoy next week 

General agreement between models for dry, sunny and warm for the coming week with HP over France/S England. The fun starts on Fri 22nd when GFS, having given up on a S-ly tracking LP, sends it to NW Scotland instead. ECM (still yesterday's output) agrees but keeps it a bit further out in the Atlantic, as does BBC WFTWA, the latter admitting some uncertainty as to its prediction. EDIT Today's ECM is now the one to bring a local LP in, crossing Scotland on Sat 23rd, and then compensates by building a large HP from the SW Tue 26th

On from there (GFS) the HP is suppressed for a bit with W-lies but re-asserts itself Thu 28th and we finish up with a ridge Sun 31st squeezed from the N (an Atlantic LP) and the S (something thundery-looking over France).

GEFS as you would expect from the above, for the S up to 5C above normal for this week and dry, dipping on Fri 22nd to a mean value about normal but with quite a lot of variation and intermittent rain from then on. Scotland & NI get the warm spell but temps after that tend to be a little below normal, with definite rain around the 21st and more generally for the rest of the period.

Spare a thought for Norway, only just across the N Sea, and according to GFS the wrong side of the 552 dam line for all this time, temps 6C below normal - and some of that comes uncomfortably close to the E coast on Wed 27th. Big patch of cold air in E Europe too.

Yes should have said a v good 5 or 6 days then a breakdown. I reckon we could squeeze a 28c somewhere. 

Ecm builds a massive high pressure in its later stages this morning hopefully its onto something.

GFS has high pressure around the UK through to Sat 30th ; occasionally pushed S by depressions brushing the NW Fri 23rd & Tue 26th but renewing from the SW. A more general drop in pressure over the UK Sun 31st - Tue 2nd but still with winds from the S.

GEFS warm to Fri 23rd then mean of runs close to seasonal norm but with more scatter than yesterday, majority on the cool side balanced by some extremely warm ones. Drier in the S throughout to Tue 2nd than previously forecast, chance of a little rain around the 22nd. A greater incidence of rain the further N you go, and continual for N Scotland & NI.

ECM similar but emphasises the LP on Fri 23rd with some cool NW-lies in its wake; and then leaves out that on Tue 26th altogether with strong rise in pressure

http://www.wxmaps.org/pix/prec4 10-day summary indicates the usual NW/SE split in temp, but the rainfall pattern for week 2 is more interesting, with most of the rain inland rather than on the coasts - convective showers perhaps?

GFS pressure pattern is for HP over the S of the UK with troughs brushing the NW (esp Fri 22nd) until Wed 27th, when pressure drops over the UK generally and a well-defined depression develops over the western approaches Tue/Wed 2nd/3rd 

ECM similar at first but stronger HP for the week of Mon 25th and showng no sign of declining by end of run Wed 27th

GEFS changed a bit since yesterday; for the S warm until Sat 23rd, a bit of a dip with some rain; warm and dry again until Sat 30th then repeat cooler and rain; then warmer again. Scotland & N England temps after the 23rd stay closer to normal (with the usual scatter) and rain throughout that week with some runs showing big totals. The Midlands have the temp pattern of the S but also the large rainfall spikes.

One would need to be on them to forecast a cooler than average summer in the UK this year. Could happen but it's very unlikely and already there are signs of the west European heat dome in some of the output. The crucial question looks like being rainfall amounts.

ECM looking pretty warm with potential for some fireworks at the end I'd say?

GFS as usual not buying in, but the op run is one of the coolest in the set.