Model output discussion - first hot, thundery plume of the summer

[Andy Bown]

20 minutes ago, MattStoke said:

Precipitation up to the end of Friday 26th July.

Much of that over England and Wales will happen tomorrow and Saturday (19th and 20th).

[MATTWOLVES 3]

The mean is not as intense compared to the op by a long way... Still becoming very warm.. But the core of heat is trending East. We also see a decline in temps by day 10.

[Connor Bailey Degnan]

Looks like the OP was a major, major outlier given the ec mean.

[Man With Beard]

28 minutes ago, Met4Cast said:

Not quite the 40c being touted by some on this forum, then? 

The ECM is certainly exceptional but it's not like we haven't been here before with this model, it does like it's extremes in recent years. Looking at the ECM mean it certainly seems the Op was one of the warmest if not THE warmest of the pack. I still think 32-34c is likely widely with a localised 35/36c somewhere in the usual spots. 

If we see a continuation of this evenings ECM in the morning (given it's lack of consistency in recent days) and some support from other models, then we could probably expect to see something exceptionally warm. But as things stand, it's one run and it's an extreme run at that.

I've been watching these charts avidl during all recent heatwave, this year and last, and actual temps are always 2 to 4C higher than what is shown here. 

Anyway, the ECM ensembles clearly have no time for the heat extending past Thursday. 

[Frosty.]

Really good  Ecm 12z ensemble mean tonight up to and including thursday, twas never going to look as extreme as the operational but that doesn't preclude the possibility that in reality we could be in for one hell of a scorcher next week!!!!!!!!!!!

Edited July 18, 2019 by Jon Snow

[Mike Poole]

16 minutes ago, Singularity said:

Sigh... again, that’s a 12z (noon) chart as the output ends there. Also the temp at that time again.

I’ll seek out the raw max temp figures for Wed-Thu shortly - or someone else might... either way. I’m not expecting to see a 40 on those, just noting that it could feasibly happen by Friday if it stayed sunny enough (which, of course, has to be considered a low probability at this range).

 

This is the key phrase: probability. It doesn’t usually include a 40*C max but at this time there’s reasonable grounds to consider it possible. Hence it’s with some discussion, for entertainment (be that thrill or horror...!) value.

For all we know, we might see a quick breakdown with a max barely past 32. It’s all plausible to some degree or other.

I agree, and if records are going to be under threat, and it's too early to say, it is worth separating consideration of uncertainty and (spatial) variability.  Right now we are mainly seeing in the models uncertainty over the evolution, once that starts to get resolved the focus may shift to local variations which the global models can't pick up, so then we move to high res models and eventually to observations.  

At the moment I'd put the probability of the all time record going at about 25%.  I'll include updates (using a Bayesian framework) in occasional future posts, as more information, of whatever sort, becomes available.....

[northwestsnow]

Yes DET will be an outlier for sure, going to be some seriously interesting runs over the coming 24 hours or so as the models get to grips with the evolution.

Either way, its going to get warm/hot next week, intensity/duration still an unknown.

[Met4Cast]

Possibly the biggest outlier I've ever seen..

[MATTWOLVES 3]

It's only Thursday and the ECM op is already on the pop!!! Strooth... 

[Djdazzle]

Of course it was an outlier. But still looking at mid 30s next week.

[mb018538]

And the award for most blatant and obvious outlier of the year goes to......ECM 12 op! Come and collect your award please.

It was always going to be miles above the rest. It’ll be gone by the morning and we will be back to what we know will probably happen - hot until wed/thu, thundery breakdown before low pressure moves in.

[Mr Frost]

12 minutes ago, Djdazzle said:

Of course it was an outlier. But still looking at mid 30s next week.

I prefer the term trendsetter...

As you say though - mid 30’s is not be sniffed at and there is a chance of that happening. 

Large parts of England approaching 30c - great stuff! 

Fascinating spell of models/charts viewing - very enjoyable to wake up to and go to bed to every night at the moment.

Edited July 18, 2019 by Mr Frost

[Guest]

5 minutes ago, Mattwolves said:

It's only Thursday and the ECM op is already on the pop!!! Strooth... 

Well worth saving! One of the hottest operationals I've seen, if not the hottest  Like others say, it'll be gone by the 00z, though the heat is coming in some form 

[Djdazzle]

4 minutes ago, mb018538 said:

And the award for most blatant and obvious outlier of the year goes to......ECM 12 op! Come and collect your award please.

It was always going to be miles above the rest. It’ll be gone by the morning and we will be back to what we know will probably happen - hot until wed/thu, thundery breakdown before low pressure moves in.

I wouldn’t say that just yet. 

[Met4Cast]

For what it's worth, UKV is going for mid 30's by Tuesday

 

[Singularity]

Found Friday's raw ECM max; 37*C. 

Given the typical underestimation that @Man With Beard has handily recalled for us, that suggests 40*C is not out of the question from that particular sequence of events.

 

Anyway, that'll do on that matter, as it does look to be a serious 'wildcard' outcome based on the EPS.

It's far from nonsensical though. I've looked through the various models and ensembles this evening and found that the base idea of splitting the Atlantic trough into northern and southern parts is shared by a good number, including the GEM and ICON 12z runs (for what they're worth!). 

The very different route unfolds because for whatever reasons, ECM not only performs that split some 500 miles further west than the vast majority of other model solutions do, but also brings into play another trough from over by Newfoundland on Wednesday that 'steals away' the southern trough portion before it can break down our hot spell directly.

 

That new player trough is present on other models, but much weaker and slower, so it misses the boat, so to speak.

I'm now wondering whether that trough being as fast and strong would force a slower breakdown even if the trough split as far east as ICON and GEM have it happening.

Assuming we even see the trough split to begin with. The FV3 and JMA 12z runs could hardly be further from that.

Uncertainty is pretty much at the maximum possible level.

[mb018538]

5 minutes ago, Met4Cast said:

For what it's worth, UKV is going for mid 30's by Tuesday

 

Beeb going for 32c - ukv could well be right with a couple of degrees higher. We will see!

[Captain Shortwave]

I guess the first question is whether the ECM has thrown out an erroneous solution early doors with that cut off low. How big was the cluster going for this? 

I think the 00z suite will be of interest, the UKMO might be a good marker, if that suddenly throws out this cut off low then we might see the solution gather momentum. 

I guess for now we can consider Monday very warm/hot and Tuesday and Wednesday hot (potentially very hot) with a front pushing broadly east. Hard call with options of an ordinary two day wonder, a humid wet mess and a once in a few hundred year event all available from the semi reliable timeframe.

[feb1991blizzard]

1 minute ago, Singularity said:

Uncertainty is pretty much at the maximum possible level.

Agree with most of your post but the uncertainty is only really how hot its going to get and last for, its a certainty it will be hot to very hot i suppose  how much rain and how far East it gets is still another variable though.

[Man With Beard]

12 minutes ago, Mattwolves said:

It's only Thursday and the ECM op is already on the pop!!! Strooth... 

The ECM op of the past 3 days has either been in the hottest or the coolest clusters! 

But judging by where cause of the uncertainty lies - namely, the dealing with the Atlantic trough - I think things will start to firm up tomorrow. One needs to also bear in mind - a UKMO/ECM op run combo will usually lead the way at D5/D6. So a very hot Wednesday looks in the lead right now, to me. 

[Man With Beard]

Just seen individual ECM ensembles members for next Wednesday, pretty much 50% of members in the mid 30Cs, maybe 40% closer to 30C and a few have pushed the heat out already. 

[Djdazzle]

T

1 minute ago, Man With Beard said:

Just seen individual ECM ensembles members for next Wednesday, pretty much 50% of members in the mid 30Cs, maybe 40% closer to 30C and a few have pushed the heat out already. 

I think that with the UKMO 12z, I’d favour the first option. Quite a few GFS ensembles support it too. I know it’s a cliche, but the 00z runs will be telling.

[Frosty.]

3 minutes ago, Djdazzle said:

I know it’s a cliche, but the 00z runs will be telling.

Another cliche..more runs needed!!!!

[MATTWOLVES 3]

All this talk of heat is making me quite dry!! Let's dampen things down a tad by looking at tomorrows rainfall... We have band pushing NE in the morning, followed by heavy showers, and it appears we have more rain into the south during the evening!!! What a start to the holidays!!!! 

[Man With Beard]

Looking further ahead with the ensembles. Including the op and control runs, on Thursday, 21 out of 52 members look set for the mid 30Cs or higher, and on Friday, 11 out of 52 members would still be in the mid 30Cs. So a bit more support than the mean chart would suggest.