Model output discussion - hot spell beckons but then what?

[MattStoke]

GFS looks to have the heat slightly further west too. 20’C+ uppers as far west as the Welsh border on Thursday instead of just over the South East. Actually quite a bit more widespread. A very hot day for many!

Edited July 21, 2019 by MattStoke

[Djdazzle]

GFS 6z also has heat further west into Thursday.

EDIT - Matt posted same time as me!

Edited July 21, 2019 by Djdazzle

[Mike Poole]

Second burst of heat on the GFS 6z, here T84 and T90:

And T96:

[northwestsnow]

30deg at 9am next thur in the SE , thats really insane heat .

 

[shaky]

Well who didnt see that coming cos i did!!gfs backtracks towards ecm and pushes the 20 degree 850 temps much much further west for thursday!!

[ancientsolar]

the positioning of the low on GFS 06:00 is marginally further North on Thursday than the 00:00 .. which i'm guessing is allowing more heat from the South to push it Northwars losing momentum on the Eastwards drive..

[Djdazzle]

I would say the odds of 100F on Thu are increasing.

[MattStoke]

3 minutes ago, Djdazzle said:

I would say the odds of 100F on Thu are increasing.

GFS has 34’C in London, so maybe 36-37’C if that run comes off. Quite a lot of cloud around though, at least further west.

[Don]

3 minutes ago, Djdazzle said:

I would say the odds of 100F on Thu are increasing.

Me too.  I did say at the beginning of the year that 2019 could be a real eye opener and that could well be the case!

[Mike Poole]

19 minutes ago, Djdazzle said:

I would say the odds of 100F on Thu are increasing.

Yes, I think so too, probability of the record going now about 20%, up from 13% last night.  But a note of caution, GFS 6z has peak temperature Thursday at 32C, maybe looks a little short of what we might expect, until you look at the cloud cover at same time, T108:

Edit, Matt beat me to it!

Edit, that cloud chart doesn't often get posted, so to be clear, white is low cloud, red high and yellow in the middle.

Edited July 21, 2019 by Mike Poole

[kold weather]

Just now, MattStoke said:

GFS has 34’C in London, so maybe 36-37’C if that run comes off. Quite a lot of cloud around though, at least further west.

Yeah, ICON has a small area of 34-36c in Kent/London region, so in that set-up its certainly possible.

Of course this is still a very fluid set-up, and we could still easily see a shift for the end part of the week.

What does look likely is a top temperature on Tuesday that may well challenge the daily record.

[summer blizzard]

2 hours ago, Man With Beard said:

Well a strange irony on this forum - at the end of June, it was like mid-winter, with many including me salivating over the 850s charts, yet came to little more than a typical summer hot spell. Now we have genuine record breaking potential at just T108, and it's fairly quiet! Is there a sense of cry wolf going on?? 

As @Loifeless mentions, ECM maxes similar to previous runs. After usual adjustments to ECM raw data, we may expect the following maximums this week:

Monday 30C

Tuesday 34C

Wednesday 35C

Thursday 38C

Friday 30C 

However, the highest temperatures are dependent on the pattern not shifting any further east. 

Probably because it’s a largely south east affair. Here in Leeds temperatures will be around 30C on Tuesday and Wednesday which is hot but happens most years and is therefore not spectacular.

Plus without wanting to change topic I think most people from the Midlands north probably don’t have much time for getting excited about the whims of Londoners given the current real world situation.

..

Bringing it back to the output it’s interesting in the longer term that enhanced trades are forecast widely in the Pacific. That may suggest a more westerly pattern heading into early August.

 

[Guest]

Even on Thursday with the slight westerly correction partial thicknesses are falling rapidly even through the afternoon. GFS has 31c over London at 09z however maxes are ‘only’ 33/34c by 18z as 850s are 6-7c cooler over the capital by 18z than 09z. An even bigger fall in 850s occurs here, 22c at 09z to 11c at 18z. 

For any records we’d need another 12hr delay in the rapid, borderline spectacular collapse of 850s from the west, possibly the biggest/quickest reduction ever to occur, over 15c fall in places in 18hrs. 

[Djdazzle]

4 minutes ago, Alderc said:

Even on Thursday with the slight westerly correction partial thicknesses are falling rapidly even through the afternoon. GFS has 31c over London at 09z however maxes are ‘only’ 33/34c by 18z as 850s are 6-7c cooler over the capital by 18z than 09z. An even bigger fall in 850s occurs here, 22c at 09z to 11c at 18z. 

For any records we’d need another 12hr delay in the rapid, borderline spectacular collapse of 850s from the west, possibly the biggest/quickest reduction ever to occur, over 15c fall in places in 18hrs. 

Have no fear Chris. The 12z runs will continue the westwards correction. I think the models are starting to play down the LP a bit now.

[MATTWOLVES 3]

All this talk of heat is making me froff at the mouth... Well parched!!! So I will take a look at some appreciable rainfall amounts towards the NW over the coming hours.. This rain almost extending into NW parts of the Midlands for a time. Things improving on Monday... They do say get the rain in first and the heat will follow. Wednesday also looking of interest, thunderstorm potential devoloping through the Midlands Northwards.. The SE looking to stay hot/sunny and parched.... Jammy gits! 

[Frosty.]

Just looking at the GEFS 6z mean for the week ahead, to me it's better than yesterday in that it's slowing down the breakdown from the west later in the week with the heat holding its ground longer meaning there is a better chance that thursday will still be hot for the majority and even friday could be warmer than was shown yesterday for the east / southeast.

Edited July 21, 2019 by Jon Snow

[knocker]

3 hours ago, Djdazzle said:

Not disagreeing with you there. Just think that the depth of the low is being overplayed, which is quite a common occurrence with these type of LPs.

Sorry I've just come in but you keep referring to this low. What type of LPs do you mean and is the 'common occurrence' based on some personal research or are you quoting? I'm not nit picking but peeps on here often make statements of a similar nature with no reference or any attempt to explain why. I just feel this has the potential to mislead people who perhaps don't possess your expertise.

I personally find nothing odd about the fax chart for Thursday albeit it might be adjusted today

 

Edited July 21, 2019 by knocker

[danm]

58 minutes ago, summer blizzard said:

Probably because it’s a largely south east affair. Here in Leeds temperatures will be around 30C on Tuesday and Wednesday which is hot but happens most years and is therefore not spectacular.

Plus without wanting to change topic I think most people from the Midlands north probably don’t have much time for getting excited about the whims of Londoners given the current real world situation.

..

Bringing it back to the output it’s interesting in the longer term that enhanced trades are forecast widely in the Pacific. That may suggest a more westerly pattern heading into early August.

 

Bizarre comment in bold. 

Could be a record breaking week coming up, more likely the July record rather than the all time record. Still plenty of factors to fall into place but should be fascinating viewing over the next few days. 

Yes, those in the NW will be wondering what all the fuss is about. 

[Singularity]

FV3 doesn’t tighten the low up enough to prevent the upper level outflow spilling across the UK by early Thu. It also cuts off the continental flow sooner.

ECM is very different in this regard with a hot, sunnier continental flow right through Thu for all but the far west.

06z ICON more or less splits the difference.

[MATTWOLVES 3]

The ECM mean is not to bad out to day 10....the extended mean out to day 14 also shows a slight improvement... By day 14 the mean being around 9.3c for the South... And 60/70 of runs going above this.... The pressure mean was roughly in at 1016mb..

Edited July 21, 2019 by Mattwolves

[Methuselah]

From what the models are consistently indicating, there's nae much time left, for a 'repeat of 2012' to come along?

Edited July 21, 2019 by Ed Stone

[shaky]

19 minutes ago, Singularity said:

FV3 doesn’t tighten the low up enough to prevent the upper level outflow spilling across the UK by early Thu. It also cuts off the continental flow sooner.

ECM is very different in this regard with a hot, sunnier continental flow right through Thu for all but the far west.

06z ICON more or less splits the difference.

Arpege is the latest run to join ecm camp and push the hot air further west at 72 hours compared to its 00z run!!brilliant stuff!!

[Singularity]

2 minutes ago, shaky said:

Arpege is the latest run to join ecm camp and push the hot air further west at 72 hours compared to its 00z run!!brilliant stuff!!

Good spot. A slight slowdown in the movement of the little low out of France allows the highest 850s to advance further NW on Wed. Surface flow stays off France for longer too.

Not sure how Thu would be affected by this change.

So many circulations at once next Tue-Thu! Will higher model resolution be the winning factor? Time will tell!

[knocker]

After some adjustment of the upper trough the low is now here with the gfs. Frankly I find the Spanish Plume potential more interesting but, hey, that's just me

 

[Methuselah]

Some more good news: once the heat gets blown away, the GEFS 06Z operational keeps T850s somewhere close to 10C, providing for 2m maxes of between 23 and 25C...So, nae a bad outlook at all?