ECM goes full heatwave tonight beauty of a run.

 22c 850s back into Blighty by day 10 . will they bring record 2m temps this time?

 

This run would have 30C reached every day next week and mid-30s on the last day (Thu).

 

 

This run would have 30C reached every day next week and mid-30s on the last day (Thu).

 

 

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Also 40s almost every day next week in France.

 

 

I've seen your CET prediction for July....

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I've seen your CET prediction for July....

  If that run verifies, he may well be closer than us!  

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Y

 

Also 40s almost every day next week in France.

Heading to my house in Mâconnais next Thursday. Ideally a blistering heatwave for a week before to dry up the landscape into Tuscan yellow (by all accounts it’s fetting there already), and then pleasant late twenties when I’m there.

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ECM has come on board since yesterday and now agrees with GFS, the depression around the beginning of next week now staying out west and pumping up warm air from the south. GEFS shows this warmth hanging around until the end of July at least (a clear majority, though not every run in the ensemble). GFS has a few shallow lows appearing from time to time later on  in the block of warm air - transient features but it would be nice to have a thunderstorm, haven't seen one here for ages.

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Growing signs of a heatwave or heatwavelet later this month. Still too early to be certain. 

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GFS 00z showing good heatwave potential later next week with high 20s, low 30s likely should it verify. The op at the top end of the ensembles throughout FI.

ECM much more progressive with the low so just a short glancing blow of heat with unsettled conditions further north and west. I can see it being a reasonable outlier in its data set.

UKMO somewhere in between and perhaps, at this early stage, the most likely option going forward.

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Looks like a very decent outlook for points S/E, whichever way things land. Some much needed rain through Friday night then an improving picture. As Brian says, chances of a heatwave depending on exact track and extent of low out to the NW next week.

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Interesting feedback from MetO on the so-called "UKMO Extended" chart that sometimes gets posted on the MO (more especially in winter ):

There is no T+168 chart for the deterministic run (as I suspected), the only T+168 charts that exist for the UKMO Unified Model are for the global ensembles (MOGREPS-G), so that chart that sometimes gets posted is not the "next" chart for the usual UKMO run to T+144 that we get to see. Most likely it is the control run of the MOGREPS-G.

So we can finally drop the "Extended" label.

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GFS 00z showing good heatwave potential later next week with high 20s, low 30s likely should it verify. The op at the top end of the ensembles throughout FI.

And the 06Z goes right at the bottom of the pack by contrast. A very wide spread, 15C in terms of 850s after just 10 days.

Run 20 goes for 850s almost as high as the recent record-breaker (23C) but again the 2m temperatures barely break 30C, strangely.

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A battle now shaping up, between heatwave and heatwavelet which seems to hang on how deep and far South the weekend’s disturbance swings.

The runs showing a more meridional pattern and deeper low (GFS06z, ECM, ICON) then bring it across is introducing cooler air. The flatter more zonal runs (GFS 00z, ECM yesterday) take longer to heat up but last longer too.

EDIT: always interesting looking at the more extreme members of GEFS. P20 of the 06z would break the 2003 record for the U.K., might well beat 2003 for intensity and longevity in France (but probably not beat this June for absolute max though it could get close). When maxes on the ensemble chart show 33-34C you can easily add another 4 or 5C to get to real national maxes. 

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I've seen your CET prediction for July....

 

Gonna need a massive amount of luck but a significant heatwave is definitely possible.  

UKMO at 144h looks hot for the south 16c 850s, absolutely roasting in France though 24c widely.  That's not normal, maybe the new normal?

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12z GFS so far going very similar route to the disappointing 06z. ICON is poor too. Feeling less optimistic now.

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12z GFS so far going very similar route to the disappointing 06z. ICON is poor too. Feeling less optimistic now.

 

GFS isn't that bad still hot, ICON is unsettled but still manages to get 20c 850s to the south . GEM the star the roasting run 23c 850s into the south prolonged and thundery. 

 

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Whatever happens in the UK,  France looks destined for another brutal heatwave remarkable to have two barely a month apart.

 

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GFS isn't that bad still hot, ICON is unsettled but still manages to get 20c 850s to the south . GEM the star the roasting run 23c 850s into the south prolonged and thundery. 

Yes GEM is very hot. Has that thing which only very few recent runs have shown: low pressure getting cut off to the West and declining with high pressure filling in to North West

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Whatever happens in the UK,  France looks destined for another brutal heatwave remarkable to have two barely a month apart.

I’m there from next Thursday. Depending on run, by then it’ll either be wet with some thunderstorms and fresh air moving in, or very very hot with maxes up to 40C again. Mid-high 30s early next week look nailed on though.

Even the more unsettled runs have Southern England getting at least one 30C day too. 

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I've never, ever understood why people fail to look at the ensemble guidance, be it winter or summer.

As I've posted a bit recently, down here at least the ECM ensembles have been rock-solid in supporting a warm spell, with a low chance of it turning hot (i.e. 28C for London) - 10% to 20% chance of that, as has been the case for days.

The 850 ensembles similarly show a very low chance of 20C 850s affecting us, regardless of what op runs are showing.

Here, again, is the link to the ECM ensembles. I know I posted this link endlessly during the winter, but it bears repeating. Hell, we waited well over a decade to get this data, make the most of it while it's still free!

https://weather.us/forecast/2643743-london/ensemble/euro/temperature

(EDIT: Not to say we won't see 28C or above, of course, just that it's not the favoured option in the ensembles. It's similar to rolling a die and hoping for a 6.)

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