Model output discussion - August hot spell - how hot, how long?

[Djdazzle]

Looking for some positive - at least tomorrow’s runs will be better than tonight’s. No way will low pressure be that deep. Hopefully slightly higher pressure to the east will begin to show its hand.

Quite amazing how we have found ourselves in this position - the curse of the UK!

[Mike Poole]

3 hours ago, Mark wheeler said:

Oh no . Broad agreement too , Bring back the heat please . That’s Gem , Ukmo and Gfs at 144hrs 

970 low in summer, quite unusual.  But still far enough away it might be modified.  

Thanks for all the great informative posts during the hot spell, normally I would have been joining in, but I have had some things to deal with and little time to post.  And it kind of gets difficult to start again, because if I’m posting regularly, I kind of know what the GFS bias is, what the GEM thinks, which model I currently favour, etc. from the previous runs.  It is less easy to pick it up again from scratch.  

So a couple of things to consider, first that +AAM signal seems to be rapidly going down the loo, as per CFS:

But also, the SSTs all around the UK are now well above normal, with the absence of settled conditions things could get very wet.  I’m not convinced the unsettled spell will last too long, but as often the case, it is with the start of September that settled conditions often take hold, and I see no reason why not this year.  

All the best, Mike.

[ribster]

Is that tumbleweed...

[mb018538]

53 minutes ago, ribster said:

Is that tumbleweed...

Yep. Outlook looks dreadful, as it has done for a few days now. Not sure what people were expecting to be honest.

[Paul_1978]

15 hours ago, Mark wheeler said:

Oh no . Broad agreement too , Bring back the heat please . That’s Gem , Ukmo and Gfs at 144hrs 

I’m personally looking forward to a bit of lively weather, bring it on. We don’t all like high heat and oppressive humidity

[Alexis]

1 hour ago, Paul_1978 said:

I’m personally looking forward to a bit of lively weather, bring it on. We don’t all like high heat and oppressive humidity

It's just the chilly air that follows that low that worries me!

[Frosty.]

Shame it’s all gone quiet on here and is no longer a HOT topic, but did anyone really expect these very exceptional conditions to just go on and on and on??...let’s be realistic shall we!!!..if you’re in the s / se and love hot weather you have been in heaven for quite some time now, if you don’t it’s been hell..but anyway, enough waffle..the models show further warm and humid thundery conditions for a while yet, at least across England & Wales BUT then a marked change, much cooler more autumnal conditions, especially further north according to the 0z output...

Edited August 15, 2020 by JON SNOW

[MP-R]

34 minutes ago, JON SNOW said:

Shame it’s all gone quiet on here and is no longer a HOT topic, but did anyone really expect these very exceptional conditions to just go on and on and on??...let’s be realistic shall we!!!..if you’re in the s / se and love hot weather you have been in heaven for quite some time now, if you don’t it’s been hell..but anyway, enough waffle..the models show further warm and humid thundery conditions for a while yet, at least across England & Wales BUT then a marked change, much cooler more autumnal conditions, especially further north according to the 0z output...

No, but I don’t think many expected it to turn exceptionally poor straight after. Just some seasonal Azores ridging and general warmth but suit most people just fine.

Fwiw, it doesn’t look QUITE as bad as yesterday but the outlook doesn’t look clever. Ideally we’d want the low to stall to the west or pass through quickly with a high behind it, although that would be the cooler solution, it would probably also be the sunnier one.

[Ice Day]

No wonder it's so quiet in here, pretty abysmal runs for mid August.  As said above, it's unusual to see such a deep Atlantic low at this time of year, the ECM has it modelled at 975 for next Thursday / Friday:

   

As always though, things can change quickly but it looks like we'll have to endure some rubbish for a few days at least.  All this rain is good for the garden though 

 

[Mandrake]

That low does look very deep for what is still summer and I wonder if its a direct correlation of all the energy thats stored within Europe.

For light relief I share this remarkable summers temperature chart so far for my locale in Southern UK (sorry I know its not model related)

 

[mb018538]

15 minutes ago, Mandrake said:

That low does look very deep for what is still summer and I wonder if its a direct correlation of all the energy thats stored within Europe.

For light relief I share this remarkable summers temperature chart so far for my locale in Southern UK (sorry I know its not model related)

 

It’s not really - it’s just the remnants of tropical storm Kyle being caught up in the mid latitudes and engaging with the jet which is causing the rapid cyclogenesis. Happens most years in late summer/early autumn as tropical systems recurve back into the Atlantic

[Mark wheeler]

Some differences between the GFS and UKMO today at 144hrs , Nice for the Ducks I suppose and those that are fans of wind and rain . 

[mb018538]

Nothing much to cheer on the 12z runs - no signs of anything settled appearing in the next 10 days. No wonder it’s so quiet. It’s that rubbish I can’t even be bothered to post a chart or two

[summer blizzard]

Models are certainly indicating some lovely charts for those of us that want summer done with from next weekend albeit i suspect we might see might see the pattern die back in terms of how cyclonic it may be in the final week (blocking still to the north and west but likely drier as we get weaker, flabbier lows). September pattern is up in the air at the moment. 

[Mike Poole]

On 14/08/2020 at 17:38, Mark wheeler said:

Oh no . Broad agreement too , Bring back the heat please . That’s Gem , Ukmo and Gfs at 144hrs 

Just quoting Mark’s post from yesterday (again!), to compare today’s 12z at T120, i.e. like for like, here’s todays runs +ECM:

Looks like on average both a correction west and reduction in intensity ( may be connected),  GFS goes a bit weird after this taking the low northeast.  Low probably hits Friday now.  

[stodge]

Evening all

Having had seven days of 30+ maxima, the last thing I want is more heat but let's see what the models proffer tonight:

12Z at T+144 from ECM, GFS OP, GFS Control, GEM and UKMO

Variations on a theme if I'm being honest - I don't see much evidence of the LP slowing or stalling and variations on track and intensity to be expected at this range. It could bring a brief warmer interlude back to SE parts but otherwise it's cool with rain or showers and for those who seem surprised we get a deep LP in mid-August, just look up the Fastnet Race Disaster of 1979 - the LP then was 975 MB over southern Ireland.

Looking further ahead:

So that's T+240 from GFS OP, GEM, ECM and GFS Control

Perhaps a transient ridge but this looks a typical early autumnal profile and let's not be surprised - we can and often do get a poor spell late in August while in September (often in response to the energy redistribution of tropical features over the western hemisphere) HP builds back as the Atlantic flow is disrupted and/or an ex-hurricane pulls the jet back north. In truth, neither TS Josephine nor TS Kyle look to have much of an impact and for now the Atlantic looks quiet but as we know that can and does change quickly.

I can only speak for myself but I enjoy HP in September and October more than July and August but that's just me.

 

 

[Man With Beard]

Slight alteration on the ECM this morning. The Atlantic low for the end of the week now performs a winter-like turn to the NW, and as a result we see a slight NW/SE split, with the NW being wet and windy, and the SE warmer, slightly less windy, though still "changeable" rather than settled. 

This is a bit more like ensembles from a few days ago but, as we often say, it's just one run.

[johnholmes]

Sun 16 August 500 mb anomaly charts update

Ec-gfs little sign of any ridging on either chart other than v far east, mobile w’ly into uk, ec trough well east, gfs e of n sea into w’ern Europe

Noaa shows +ve heights/ridging w Greenland into trough between Iceland nw uk with w’ly over atlantic (after v slack area re ridging) then into uk and reasonably strong flow

All 3 suggest no heat and a mainly changeable or even unsettled spell for 6-10 day period, confluent at entrance so possibly deepish lows towards nw uk (?any ex TS involvement would exacerbate this).

Nb:-contour over central uk (564DM) spends much of time around or above 60N so temps likely to be below normal at times

Nothing on 8-14 suggest any real change in this pattern 6-10 day.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

https://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

 

Edited August 16, 2020 by johnholmes
slight wording changes

[Guest]

Looks like Autumn arriving early...

[Frosty.]

45 minutes ago, DCee said:

Looks like Autumn arriving early...

Not until beyond the week ahead though!..there’s plenty of warmth still in the tank for the next week or so (for sure nothing like the intense heat of recent times) but still pleasant enough, at least further s / e / se BUT beyond that it looks cooler for sure, especially further n / nw!..just using the ECM 0z ensemble mean as 1 example!

 

Edited August 16, 2020 by JON SNOW

[summer blizzard]

GFS this morning tried to cut-off a low towards day 10 but fortunately kept it far enough east so as to avoid pumping any warm air north but that's probably the best crumb for warm lovers. 

For people like myself it looks like a wetter outlook than most of July and August to date but no real sign of summer trying to hang on. 

 

[ICE COLD]

Nice to see the dark blues making a come back as the polar vortex starts to wind up . 

[Mike Poole]

23 hours ago, Mike Poole said:

Just quoting Mark’s post from yesterday (again!), to compare today’s 12z at T120, i.e. like for like, here’s todays runs +ECM:

Looks like on average both a correction west and reduction in intensity ( may be connected),  GFS goes a bit weird after this taking the low northeast.  Low probably hits Friday now.  

Sorry for self quote, but just for the charts yesterday T120, compare today T96 re track of the low:

Low deepest on ECM and UKMO, but will somewhat fill before it impacts the UK.

Moving on with ECM:

T120-168 returns the south at least to something more seasonal....

 

 

Edited August 16, 2020 by Mike Poole

[mb018538]

Another day passes....check models. Still showing rubbish weather without any prospect of change. Back again tomorrow then...

[Captain Shortwave]

Despite the rather cyclonic conditions forecast for the coming week. Temperatures will probably do okay with a fair amount of warm air around. Also the combination of those will mean that there will be some pretty hefty showers around away from the fronts that will move through during Wednesday.

Week 2 however does look pretty flat unfortunately.

   
 

The dominant trough to the north east isn’t going to be helpful.