Model Output Discussion - The Start Of Summer

[StormChaseUK]

Agreed, the 18z will ramp it all up again.  Subtle changes with the Low.

[kold weather]

I think to my eye FV3 looks a touch off and the 850hpa profile is very odd with little pockets of extreme heat coming up but broadly not quite as mad as previous. I doubt it has too much support for that exact evolution...though I'd still suspect a 35-36c from it which lest is forget is pretty impressive for the UK.

what we lose in extreme heat from that 12z, we gain in convective potential, so not a bad trade off to be fair!

Edited June 21, 2019 by kold weather

[Methuselah]

An interesting chart, this -- warm and showery...But don't look at Greenland!

 

[Frosty.]

Anyway..the first high of June is upon us..albeit very transient!!...  Yes it's hard to believe isn't it!!

Edited June 21, 2019 by Jon Snow

[MATTWOLVES 3]

Some stunning ensembles folks... Loads of hot runs from the 12z...

[Mike Poole]

On the 6z GEFS I posted about the number that got the +24C contour into the UK at T180, there were 6, so what of the 12z suite, here T174:

8 - but some quite marginal, message is we're not going backwards with regards to heat potential next week.

[Guest]

The GFS 12z Ops is generally in the ‘coolest’ bottom third of the ensembles through next week so a huge amount still to play for but a pretty big spread after midweek. 

[Weather-history]

GFS12z's hottest ensemble

[knocker]

This is well into F1 so I'm just posting this out interest. By Thursday the upper low is filling and becoming a neutrally aligned weak trough. But by the weekend another low has formed in the base as it presumably gets a boost from the west, and then  tracks north

Edited June 21, 2019 by knocker

[Frosty.]

A quick look at the GEFS 12z mean for next midweek..I've seen worse!!!

[shaky]

Got my first prediction right about the gfs 12z earlier on in regards to a slightly toned down plume!!now am gona make another predicition and say the ecm 12z will be an improvement on the 00z and the plume will hopefully get further north this time and a bit earlier aswell!!

[I remember Atlantic 252]

18 minutes ago, Alderc said:

The GFS 12z Ops is generally in the ‘coolest’ bottom third of the ensembles through next week so a huge amount still to play for but a pretty big spread after midweek. 

couldn't believe the temps for Tues? 19 degrees max? what's that all about, 

 

[Man With Beard]

Some observations on the 12Zs so far. 

On a superficial analysis, it appears the heat envelope has shifted east for now. On yesterdays 12Zs at T144, all main models had the 20C uppers line straddling the S Coast, whereas today's 12Zs so far at T120 have the 20C line clipping the SE coast only. 

It may be tempting to think this is the start of an eastward shift that usually happens with plumes. But I think that would be a mistake. In this situation, I think late westward shifts are perhaps even more likely. This is because the high to the north is causing the weather to travel against the normal west to east flow. 

Also, as we've seen in some runs today, wind direction will be just as important as uppers. The closer the trough is, the more likely to have slightly lower 850s, but also more likely to draw in a SE flow than an E flow. 

So swings and roundabouts. Everything considered, I don't think much has changed except perhaps the quantity of heat for N and W areas. I still think we're looking at the 90Fs next week, but which end of the 90s still in question. 

[mb018538]

Don’t worry about temperatures too much at this range. I’ve got a forecast of 24c here with wall to wall sunshine here next Thursday with upper temps near 20c. We all know that’s completely wrong. Wait for more exact details as we go through the weekend! Models varying wildly from run to run, they probably want to go conservative until they have a better idea.

[summer blizzard]

8 minutes ago, I remember Atlantic 252 said:

couldn't believe the temps for Tues? 19 degrees max? what's that all about, 

 

Precipitation? The Fax charts suggest a front over the UK and the Met Office have warnings out.

We may be seeing storms.

[Guest]

10 minutes ago, I remember Atlantic 252 said:

couldn't believe the temps for Tues? 19 degrees max? what's that all about, 

 

Well rounds of convective activity pile south to north through central and western areas, there’s almost no sun simples.

[Mark wheeler]

Just for Fun , let’s give the Navgem a summer outing , looking Toasty . having said that we have better runs at the moment , but hands up who would have taken this , this time last week ?

 

[I remember Atlantic 252]

10 minutes ago, Alderc said:

Well rounds of convective activity pile south to north through central and western areas, there’s almost no sun simples.

06Z for same time was better, I was hoping for sunshine then evening thunderstorms

[Frosty.]

5 minutes ago, I remember Atlantic 252 said:

06Z for same time was better, I was hoping for sunshine then evening thunderstorms

Scotland has worries on monday..could be 4 inches (100mm) of thundery rain spreading north heralding the much warmer / humid air for the rest of next week..cloud will be a big issue next week, even with the best uppers (850's) recorded, if it's cloudy it's a waste of time! 

Edited June 21, 2019 by Jon Snow

[I remember Atlantic 252]

10 minutes ago, Jon Snow said:

Scotland has worries on monday..could be 4 inches (100mm) of thundery rain spreading north heralding the much warmer / humid air for the rest of next week..cloud will be a big issue next week, even with the best uppers (850's) recorded, if it's cloudy it's a waste of time! 

Aye cloud huge difference, this day was only around 21 degrees, full on cloud

[MattStoke]

ECM looks poised.

[Mike Poole]

I'm sure we're already to go with a chart by chart analysis of the ECM, not like it's winter or anything!

Here T120, compared to UKMO at same time:

Low completely cut off as per UKMO,if you recall it leaked on GFS FV3 but not on the old one.   Good start.

[Fourty Point Three Degrees]

46 minutes ago, I remember Atlantic 252 said:

couldn't believe the temps for Tues? 19 degrees max? what's that all about, 

 

July 1st 2015 had some cloud cover across Western England and Midlands and yet places still got into the high in the 20s low 30s. Wouldn't worry about that chart GFS is probably undercooking as per.

Edited June 21, 2019 by 38.5*C

[Methuselah]

Over all, I'd call the 12Z a stonker of a run -- even at the end, things are generally still on the warm side (850s of 7C+?)...A longish period of above average temps is maybe getting more likely. Who knows?

  

 

GEFS 12Z ensembles are as follows:

  

  

From Mr Spock to the Doomsayers: 

[I remember Atlantic 252]

1 minute ago, 38.5*C said:

July 1st 2015 had some cloud cover across Western England and Midlands and yet places still got into the high in the 20s low 30s.

hottest ever day at Wimbledon 36 degrees