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Another day, another GFS run way below the average...

The only crumb of comfort I can find is that both the GFS and ECM sit a fair bit below the mean once the high eventually moves in.

End of May and large parts of the north are stuck with daytime maximum temps at 6-8c on this mornings ECM day 10.

You'd be right. What a mess of a run. By day 9 and 10 there is still an upper trough dumped over the UK with its attendant cold pool and muck. Problem looks be the strong heat dome being pushed up into Eastern Europe at the same time which is preventing the trough exiting from our neck of the woods. Typical UK - get high pressure in and it's still rubbish. Not a good morning of model watching!

As @Alderc has alluded to, the 00z GFS run isn't good at all...high pressure in exactly the wrong place for anything decent for the UK. Cold blob gets advected down and cut off over the UK. A N/NE flow prevails and temperatures are even worse than they are now, stuck down in low double figures. This courtesy of North Sea filth being swept across a good swathe of the UK. GEM is marginally better, but still has the cold air stuck in play until day 10. Let's see what the ECM has to say.

00z day 10 6z day 10: No upper trough on the 6z, and the cold air is eventually mixed out. Much better run for the UK.

Sorry but I can't agree with that at all. Scotland, Wales and Northern Ireland had their sunniest April on record, England it's 2nd sunniest on record after April 2020. Low upper air temperatures don't simply translate into cloud. It's all to do with the airmass type. We had a cold and dry airmass dominating in April, which led to lots of cold and sunny weather.

As we all suspected - a massive cold outlier. Anything from +6 to -2 possible though, so we're still a bit clueless. It's a case where a shift of 100 miles makes all the difference. If that residual upper trough stays out of the way it'll be very nice. If it sticks close by, could be quite cool.

I've just scrolled through all 20 of the GEM ensemble members at day 10, and it's about as much good as a chocolate fireguard. Take your pick!

ECM is sadly very similar. Cold air hangs around as an upper trough lingers to the E/SE of the UK. I'd expect this is an extreme solution (much like the GEM is on the warm side) and will be a cold ensemble outlier when they appear. Reality probably somewhere in-between the two.

GEM 00z is keen for a big UK high and some very warm air by day 9/10. Temps into the mid to upper twenties by Friday there. GFS goes off the rails a bit and drops an upper trough down over the UK which gets stuck. One to be resolved no doubt.

No? Couple of day 10 ecm charts there from the last 10 days that don’t show anything settled long term at all. We’ve had few runs the last 3 days or so that have hinted at improvements that have been pushed back, but it’s been quite widely posted on here than any improvements weren’t likely in May until the last 10 days at least until -ve AAM etc was removed. It looks like taking a bit longer than we’d hoped....but weather never works to a set time does it. It’s just slowly slowly, but hopefully we will be done with this shocking weather soon enough.

Don’t even know where to start with that comment, so I won’t even bother. Just your usual casual and lazy model observation we get on here sometimes

Cracking 12z run - warm and sunny by day 10: Let’s see what the rest say. Chop and change the order of the day!

I know all models struggle slightly in this convective showery output to nail exactly where the showers will or won’t be etc, but which one do people find to be best? EURO4? Trying to work out how wet I’ll get playing golf Wednesday afternoon but am getting wildly different forecasts from different models etc. Likely that I’m going to catch a shower, but this isn’t my main area of expertise.

ECM nowhere near as good as last nights run. Looks like a lot will hinge on how this developing low below the tip of Greenland behaves and swings through: All looking quite similar at 144 hours, but all have very different outcomes by day 9/10.

GFS day 10 GEM day 10 Very frustrating to see this amount of difference in the model runs. I literally have no idea what we could be faced with in just over a weeks time.

ECM is good by day 10. I like the fact that the last 2 runs have completely gone away from rebuilding the Greenland high as we saw a day or two back. If that disappears we have a better chance of something warmer and more settled building in. This volatility is more like a winter cold chase! Every run wildly different. The old adage applies - more runs needed.

Iffy 12z runs so far. GEM has gone from lovely on the 00z to godawful on the 12z. Let’s see what the ecm says in relation to its decent 00z run.

We’re not in a full La Niña like last summer, so it shouldn’t be as bad on the whole. I’m expecting a more typical summer. Not a scorcher, not a washout. Average with the odd hot spell or two chucked in. Part of me is really hoping that as we’ve seen so much northern blocking and -AO in April and May that it just can’t continue through the summer too. Weather doesn’t work on a credit basis, but it would be incredible for 4-5 months of this to persist.

An equally depressing ECM mean. Might have to follow @Scorcher under a rock at this rate! Miserable useless weather.

Looking like most ensemble members are following this now. I’m getting seriously hacked off. It’s like a never ending bad dream for this damned Atlantic/Greenland high to keep reinvigorating when it looks like it’s going to break down. The building high over the UK is starting to look like a pipe dream, and we’re back at square one. So disappointing.

Well. It’s not too often you see this much disagreement from the big 4 at just 144 hours out. Probably best to forget about what happens after at the moment...

I’m not having that GFS run as anything other than a big outlier. Can’t be right. GEM is a bit better, but still cool and disappointing. Think if this high doesn’t topple in and we get another Greenland high setting up then god knows when it’ll settle down and warm up properly.

ECM wide of the mark with the extreme cold at day 10, but a huge spectrum of outcomes from pretty mild to cold on the table at the end of the run. One to iron out In the coming days.