Model output discussion - into July 2020

[Daniel*]

2 minutes ago, Djdazzle said:

Looks like an upgrade for heat on the 12z output so far.

I’m not seeing this upgrade you speak of on GFS tis a downgrade westerlies closer.

12z v 06z 

[Evening thunder]

Looks like an increasing trend to a SE/E biased plume/heat event again to me (all 3 'record breaking' plumes in the last 5 years gave nothing notable to the west or SW).

I'm less confident of anything notable down my way through the weekend, though widespread high temps on Friday seem a safer bet.

It's not necessarily very hot away from the SE/E though, can't see any upgrade over what the 00z/06z models showed


 

Edited August 2, 2020 by Evening thunder

[Captain Shortwave]

12 minutes ago, Daniel* said:

I don’t think that’s primed for very hot weather. Danger of a low level cool North Sea undercut well Scandi blocking is in outlook. 

The UKMO is okay, I would expect an elongated high through the U.K. into Northern Europe so an easterly feed in the south, which is fine. The day six chart has a very slack airflow so very hot towards the south east in particular.

 

GFS, well it offers some extra amplification but the handling of that trough is very messy, which doesn’t really help anyone.

Edited August 2, 2020 by Captain Shortwave

[Guest]

In similar fashion to the ICON 00z earlier, the GFS 12z keen on ushering away the heat by Sunday, though high 20s will hang on to the SE.

So good confidence on a hot Thursday-Saturday but still disagreement for the end of the weekend. GFS too progressive? We'll see how it sits in the ens in a couple of hours.

Even with the heat on this run heading away by Sunday, it's replaced by a decent build of high pressure from the SW, ensuring dry and pleasant conditions with more manageable humidity and temps back to the low to mid 20s for many. What's not to like?  

[Guest]

3 minutes ago, Djdazzle said:

Looks like an upgrade for heat on the 12z output so far.

I thought it was a downgrade, as gfs sweeps the heat away Saturday, still very hot in the south but the heats out completely by Sunday with uppers below 10c everywhere by18z, icon looks Really decent bur never gets the really hot air in. UKMO probably the best but quite close to GFS to day 6.

Still solid 7-8 out of 10 model output, was never to be a repeat of last night and I’m still pretty happy, although I will quickly become annoyed if a breakdown gets accelerated any earlier and we lose the really hot weather over the weekend...

[Fourty Point Three Degrees]

gfs 12 is a kind of downgrade on the temps for London but offers an upgrade on temps further North on Friday.  So maybe another intense nationwide hot day (friday) but things after that look like cooling off, 

Edited August 2, 2020 by 38.7°C

[I remember Atlantic 252]

GFS looks repeat of week just gone, hot Thurs, even hotter Fri, fresher from the west on Sat

[Djdazzle]

Maybe at second glance not quite as good as it looked. Started off well with better orientation of the high. Could be GFS being over progressive though.

[clark3r]

Quite a different run to the 06Z not sure what to make of this how is the UKMO run? On the gfs I still see 33 on Thursday, 35 Friday 36 possible Saturday then that’s it. Please do not downgrade further 

Edited August 2, 2020 by clark3r

[Man With Beard]

20 minutes ago, Daniel* said:

I don’t think that’s primed for very hot weather. Danger of a low level cool North Sea undercut well Scandi blocking is in outlook. 

I think on this particular ukmo run the Azores High would move over the top and join with the Scandi High, cutting off the north sea flow, but all academic at the moment considering the GFS output. 24 hours yet until Sunday starts becoming clear, I think! 

[Singularity]

Standard progression toward resolving a hot spell: Questions asked over whether disrupting Atlantic lows will help or hinder, GFS producing some of the most hindering outcomes. 

So far, the 00z ECM has felt the most credible to me based on past experience, with the Atlantic low being of some bother but taking time to clear the heat east and possibly never doing so for the SE - as was the case in that run.

Not a bad situation when even the most progressive of outcomes we’re seeing feature plenty of pleasantly warm conditions. The signal for warm easterlies getting involved to some degree or other after the weekend is impressively strong.

Edited August 2, 2020 by Singularity

[East_England_Stormchaser91]

12 minutes ago, Djdazzle said:

Maybe at second glance not quite as good as it looked. Started off well with better orientation of the high. Could be GFS being over progressive though.

Probably the latter I’d say. The up coming ECM will be interesting. If it sides with the UKMO, then I would expect a correction on the 18z pub run later on. 

Looked at the GFS again, and it really had made a dogs dinner of that low. There will be some alterations and swings yet over the next 36-48 hours

Edited August 2, 2020 by East_England_Stormchaser91

[Guest]

Boo Hiss even the ever hot GEM rapidly sweeps the heat away leaving just Friday as the only hot day and everywhere back into low to mid 20's by Saturday - usual ebb and flow from the models but a disappointing bunch of 12z's really.  

That a clean sweep that takes the heat either late Friday or through Saturday however they appear to build in a cooler high pressure block behind. 

 

Edited August 2, 2020 by Guest

[MattStoke]

The GFS is hopeless in these situations and the GEM and ICON are pretty hopeless in general. I put far more credence in the ECM and UKMO.

[Djdazzle]

5 minutes ago, Alderc said:

Boo Hiss even the ever hot GEM rapidly sweeps the heat away leaving just Friday as the only hot day and everywhere back into low to mid 20's by Saturday - usual ebb and flow from the models but a disappointing bunch of 12z's really.  

The GEM is so different from its 00z offering, it’s laughable!

No way will it sweep through that quickly.

EDIT: Even the GFS 12z is very different to the 6z (sorry @Daniel I should have looked more carefully). Have they picked up on a new signal or just overreacting to one I wonder.

Edited August 2, 2020 by Djdazzle

[Cheshire Freeze]

Models look very pleasant to me. Not the exceptional heat of yesterday's runs but who wants that anyway. Nights should be OK given light winds and the lengthening nights, even with sea temps being at their warmest in the next few weeks. 

[Guest]

Just now, Djdazzle said:

The GEM is so different from its 00z offering, it’s laughable!

No way will it sweep through that quickly.

While I tend to agree there is a quite a decent consensus the heat will rapidly be swept through during the weekend and was being described as a nailed on hot weekend last is defo under threat. GFS ensembles just coming out lets see what they say.  

[Guest]

Just now, CreweCold said:

Models look very pleasant to me. Not the exceptional heat of yesterday's runs but who wants that anyway. Nights should be OK given light winds and the lengthening nights, even with sea temps being at their warmest in the next few weeks. 

boring......hot nights are amazing, no duvet, window open and the nights sleep you get  

[Cheshire Freeze]

1 minute ago, Alderc said:

boring......hot nights are amazing, no duvet, window open and the nights sleep you get  

Not boring when you have to get up to do a 9 hour shift the next day.

 

[SizzlingHeat]

The 12z mean for Saturday does not agree with the operational. Control run is also very hot with no signs of the trough come Saturday. I believe the op is likely to be a considerable cool outlier 

[Djdazzle]

Had a flick through the GEFS for next Saturday. Let’s just say there is some serious scatter. Quite a few very hot options, a few cooler ones and a variety of different positions and orientation of high pressure.

[Guest]

2 minutes ago, CreweCold said:

Not boring when you have to get up to do a 9 hour shift the next day.

 

I work 12hrs a day at home and I have no air conditioning - fortunately the 12Z Ops run from GFS at least is very quick in its eastwards shift of the heat. As the 10C Isotherm clears through here the mean is still 17c. So an outlier of sorts but it does have some support from one or two other ensemble members. 

[Captain Shortwave]

The GFS control probably not far off the UKMO output.

Day 7

   
Easterly winds with hot air established, especially across the south. Just shows what could be on offer but you need the hot air to build over the U.K. first.

More ensembles tend to be in favour of holding the heat in place over the weekend in some forms, some easterlies, some have a cut off low in a favourable position too. However there is a lot of uncertainty as there was this morning.

[Djdazzle]

Over to you ECM . . .

May even flick through the GEM ensembles.

[SizzlingHeat]

As I expected when viewing the mean 12z. The operational is the lowest of all its members within the suite.