Very warm spell followed by cooler and more changeable conditions. Possibly another warm up in early July. All looks very typical to me in the context of the background warming we have seen in recent years.

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Jetstream in process of switching from W-ly S of the UK to SW-ly W of the UK which should help promote the forecast warmth in the SE. However by Sat 27th a fresh pulse enfolds the UK in a loop  to Tue 30th which disperses fairly quickly in favour of a NW-ly flow lasting to Sun 5th before breaking up into meanders again

GFS shows LP out in Atlantic bringing up warm SW-ly (though LP is too close to NW to give fine weather there) filling by Fri 26th but new LP W of Ireland taking track across Scotland to Norway around Mon 29th. Week ridge of HP builds from the S for the rest of that week before shallow LP runs across  the UK NW to SE (centered over England Sun 5th) and finally another weak ridge of HP forming behind it.

GEFS for the S shows very warm Tue 23rd - Sat 27th, then dipping below norm for a couple of days before the mean of runs resumes average, but well scattered, and op & control suggest another warm spell Wed 1st - Sat 4th. Some rain about from Sat 27th, a bit more than yesterday but still not much and well scattered. Scotland temp pattern similar but a lot of rain esp in the Borders Sat 27th, and not exactly dry after that. N England intermediate as usual.

ECM is similar to GFS at first but weak trough of LP from the S on Fri 26th (possibly thundery?) before the Atlantic takes over with LP well N of Scotland Mon 29th and persisting there with W-lies across the UK, HP to the S not ridging as in GFS

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ECM best of the big guns again this morning keeps the heat to Saturday then builds pressure in the south later on. The is very much in line with its ensembles recently so hopefully it's onto something. As other output not so good this morning. 

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Aah That’s the second run Ukmo will it get another feather in its hat? we can’t discard it 

http://www.meteociel.fr/modeles/ukmo2.php?ech=6&carte=1021

ECM best of the big guns again this morning keeps the heat to Saturday then builds pressure in the south later on. The is very much in line with its ensembles recently so hopefully it's onto something. As other output not so good this morning. 

Aah That’s the second run Ukmo will it get another feather in its hat? we can’t discard it 

http://www.meteociel.fr/modeles/ukmo2.php?ech=6&carte=1021

 

 

Yes certainly can't be discounted but the ECM Op, Para and Mean all much the same and all better than the UKMO. They have the weekend low arriving later, further north and have pressure rising soon after. GEM similar. 

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The big fly in the ointment for next week and into July seems to be our old enemy the Greenland high. Not a huge one, but present in all runs (some more than others) and forcing the jet stream South.

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The big fly in the ointment for next week and into July seems to be our old enemy the Greenland high. Not a huge one, but present in all runs (some more than others) and forcing the jet stream South.

But then again negative AO and sometimes even a Greenland high have been responsible for dry sunny weather during summer too. Got me thinking. If we take two major variables in our summer weather and combine them, I think we cover most types of summer weather:

• Positive vs negative NAO


• strong vs weak jet

1. Strong jet, negative NAO = 2012 style armageddon


2. strong jet, positive NAO = NW/SE split with ridging, 2009 style


3. weak jet, negative NAO = Easterlies, blocked patterns, May 2020 style


4. weak jet, positive NAO = settled and dry, summers 2018, 1989 etc

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 as if to illustrate the point: look at this coming Sunday in GFS 06z vs 00z. The single big difference is Greenland high.

And

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I’ll continue my Sunday monologue. If 06z GFS is on to something then it’s very encouraging. Pronounced Northward shift of the jet. Not a million miles off ECM. But I suspect probably an outlier.

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I’ll continue my Sunday monologue. If 06z GFS is on to something then it’s very encouraging. Pronounced Northward shift of the jet. Not a million miles off ECM. But I suspect probably an outlier.

Yes, it’s a much better run. And it looks like the high may be starting to push in.

June is this part of the world has been generally very good. A couple of raining days. A few showery days. Generally warm to very warm. Sultry a times.

June 1997 was one of the worst June months I’ve ever seen. This hasn’t been the best June, but it’s been a good useful month.

 

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Just read this for southeast on metoffice

"This Evening and Tonight:

.. Feeling chilly by dawn. Winds will be light. Minimum temperature 6 °C."

Really is that 6C a typo 🤔 Nothing lower then 13C being forecasted here but still 6C this late into June in the southeast is certainly noteworthy.

Benson as an easy search for a notable cold spot shows a 7c so I suppose that'll be close enough, maybe a few spots further east being cooler...

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12z GFS likely for the bin. Too progressive and way different to the others as well as the 6z. Expecting an outlier in the ensembles later.

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12z GFS likely for the bin. Too progressive and way different to the others as well as the 6z. Expecting an outlier in the ensembles later.

I expect this run is reasonably close to the mark in comparison to the 6z and doubt it'll be an outlier. The reason is because of the general trend it has been showing. If anything, the 6z was more the outlier.

However, I doubt it will be quite as cool and unsettled as this run is showing and GEM seems to prolong the heat.

That said, the UKMO looks very wet at the end of the week, although warm with it. In fact the UKMO is almost 2007 wet. Would be very concerned if that verifies.

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I expect this run is reasonably close to the mark in comparison to the 6z and doubt it'll be an outlier. The reason is because of the general trend it has been showing. If anything, the 6z was more the outlier.

As expected, the 12z operational not reflective of the mean.

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It doesn’t look that wet away from the NW in the UKMO 12z.

https://weather.us/model-charts/gbr/united-kingdom/accumulated-precipitation/20200627-1200z.html 

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As expected, the 12z operational not reflective of the mean.

I must be looking at the wrong Ensembles because to me it looks absolutely representative of the mean after the brief hot spell.

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I must be looking at the wrong Ensembles because to me it looks absolutely representative of the mean after the brief hot spell.

It significantly more anticyclonic up here than the mean for quite a while.

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I must be looking at the wrong Ensembles because to me it looks absolutely representative of the mean after the brief hot spell.

 

Yes afraid it looks like you are, although not sure where or what you're looking at... perhaps the 6z still.

 

Reading on this site shows for 850s and 2m that the Ops is bottom of the pack at least, if not an outlier, from this Friday 26th until the 2nd July bar one day, the 28th.

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Arpege looking toasty this afternoon 31c Wednesday. 34c Thursday.

 

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