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24 minutes ago, Alderc said:

Problem is the continued easterly flow and combined moisture amounts will produce ALOT of cloud at times, so some places at times might find themselves under uppers so 12-15C but temps could struggle to reach 20C.


an inversion?... surface cooler air from the east/northeast undercutting the warmer southeasterly?

17 minutes ago, Quicksilver1989 said:

The BBC forecasts confuse many people these days, away from the NE Coasts I reckon temperatures will be in the low-mid 20s on many days, with the exception of when organised storms cross the channel overnight, leaving some areas with persistent rain the following day. Speculating when and if that may happen is difficult at this early stage.

i dont usually take much notice of the bbc outlook, but im getting conflicting info and what looks like heat, might not be, and i dont understand why unless theres an undercutting /inversion.

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45 minutes ago, mushymanrob said:

ok, im confused...

not sure what to make of the coming conditions.

i dont understand why all model suits suggest a week or so at least of high 'uppers' from the southeast which id interpret as hot and humid, temps over 25c, t storms/heavy thundery showers at times, for most of the uk.

yet the bbc outlook and accuweather for derby only has temps 21c - 24c... so is the heat restricted to the southeast only? but why would it be relatively cool under very warm uppers of 10c+ ?

longer slack sea track over the North Sea, brisk winds? Probably hotter towards Scotland I'd guess, lighter winds?

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I wouldn't worry too much about computer generated forecasts anyway. On the early May bank holiday it was still showing 27c maxima on the 6z runs of the day it reached 29c! They are hopelessly wrong a lot of the time. Better to watch TV forecasts that have human input in my experience. Some of the hi-res models are much better with regards to temperature accuracy.

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17 minutes ago, Man With Beard said:

longer slack sea track over the North Sea, brisk winds? Probably hotter towards Scotland I'd guess, lighter winds?

thats the point in my locale... if the breeze is south of east, we get a lot of warmth and sunshine, as 'our' air tracks across east anglia first after a shorter sea track

if our breeze is north of east, even just slightly, we do get a lot of cloud as there is a long sea track/short land track.

this is whats confusing me, because a southeasterly would suggest sunshine/warmth, especially under 10c+ uppers. oh well...

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Posted (edited)
7 minutes ago, mushymanrob said:

thats the point in my locale... if the breeze is south of east, we get a lot of warmth and sunshine, as 'our' air tracks across east anglia first after a shorter sea track

if our breeze is north of east, even just slightly, we do get a lot of cloud as there is a long sea track/short land track.

this is whats confusing me, because a southeasterly would suggest sunshine/warmth, especially under 10c+ uppers. oh well...

Mushy one simple explanation is that you getting CAA in the boundary layer from the strong breeze from the easterly quadrant which is modifying the temp profile and lapse rate.. Thus 850mb temps of +12C can still only give you surface temps of around +20-22C  Always be wary of using 850mb to calculate the surface. Just a thought

sounding.thumb.jpg.46606ce2c1b7a392c9c1e79e28edc3b9.jpg

Edited by knocker
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Posted (edited)
59 minutes ago, Man With Beard said:

longer slack sea track over the North Sea, brisk winds? Probably hotter towards Scotland I'd guess, lighter winds?

Can't speak for Derby but a south east wind is usually good for Leeds in terms of hot weather since there's a reasonably long track of land - in fact, a south east wind is probably our second best direction for heat (a straight southerly is probably better). It's north east winds that are the real killer in terms of heat. I don't think we ever get low cloud from south east winds - only east or north east.

So 850 temps of 12C with a SE wind, you'd expect hot weather fairly widely, but knocker's post above should be taken note of.

Edited by cheese

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Posted (edited)
2 hours ago, mb018538 said:

I wouldn't worry too much about computer generated forecasts anyway. On the early May bank holiday it was still showing 27c maxima on the 6z runs of the day it reached 29c! They are hopelessly wrong a lot of the time. Better to watch TV forecasts that have human input in my experience. Some of the hi-res models are much better with regards to temperature accuracy.

Temperatures within 2C of the predicted value is considered a pretty good forecast by the professionals!

https://www.metoffice.gov.uk/about-us/who/accuracy/forecasts

Edited by johnholmes

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That’s interesting @johnholmes ! 

To me, I’d say models still undercooking maxima by 2c 6 hours before the event isn’t that great.....but I’d guess that this will improve with time. Met so a fantastic job I should add.

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Posted (edited)
1 hour ago, knocker said:

Mushy one simple explanation is that you getting CAA in the boundary layer from the strong breeze from the easterly quadrant which is modifying the temp profile and lapse rate.. Thus 850mb temps of +12C can still only give you surface temps of around +20-22C  Always be wary of using 850mb to calculate the surface. Just a thought

sounding.thumb.jpg.46606ce2c1b7a392c9c1e79e28edc3b9.jpg

CAA ?... cheers knocks, im sort of getting there but i dont understand that chart.  appreciate your response though. :)

tbh i use the 850's all the time, and find them to be a very good guide, but clearly they are not an infalible method by viewing them alone.

Edited by mushymanrob

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Posted (edited)

The GEFS 6z mean is a beauty for summery temperatures, becoming very warm across central / southern uk but even scotland which is usually considerably cooler than further south becomes warm too, especially western scotland..There's plenty of high pressure influence throughout but with lower heights to the south and an ongoing chance of T-storms but there would be plenty of dry and sunny weather too..it's a very blocked pattern and any changes look like being slow with the summery weather continuing well into early June..long MAY it continue!🌞:)🌡️

Edited by Frosty.
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3 hours ago, mushymanrob said:

ok, im confused...

not sure what to make of the coming conditions.

i dont understand why all model suits suggest a week or so at least of high 'uppers' from the southeast which id interpret as hot and humid, temps over 25c, t storms/heavy thundery showers at times, for most of the uk.

yet the bbc outlook and accuweather for derby only has temps 21c - 24c... so is the heat restricted to the southeast only? but why would it be relatively cool under very warm uppers of 10c+ ?

The BBC forecasts on the website are not to be trusted in my opinion- forecast temperatures are often lower than they should be. Watch as they raise the temperature predictions the day before- it almost always happens.

Even the GFS is showing higher maxes than the BBC and that is notorious for undercooking temps in warm spells.

I don't see huge issues with cloud in all honesty over the bank holiday- it won't be wall to wall sunshine but the flow off the continent is a good one for most of us, especially away from the east coast.

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image.thumb.png.e91ae84f0311087b7c2c56e281651477.png

12z looking significantly more unstable then the 06z, with lower SLP getting further into England from the south and a clearer cyclonic flow.

Stormy ⛈️

Though still chopping and changing. Tiny changes can make a massive difference when it comes to stormy setups.

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Don't like

7 minutes ago, Quicksilver1989 said:

image.thumb.png.e91ae84f0311087b7c2c56e281651477.png

12z looking significantly more unstable then the 06z, with lower SLP getting further into England from the south and a clearer cyclonic flow.

Stormy ⛈️

Though still chopping and changing. Tiny changes can make a massive difference when it comes to stormy setups.

Don't like where its going as will breakdown HP and leave the door open for cooler more unsettled conditions ultimately. Also Saturday a pretty poor day generally away from the SE.

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1 minute ago, Alderc said:

Don't like

Don't like where its going as will breakdown HP and leave the door open for cooler more unsettled conditions ultimately. Also Saturday a pretty poor day generally away from the SE.

I can see where you are coming from and can understand it may be frustrating if people have plans for the bank holiday weekend. I think some may miss the thunderstorms during the day on saturday, at night I think the risk of more organised storms off the continent. Temperatures may still get into the mid 20s down here... bit of a lottery. 

Sunday looks worse in my view because of the huge CAPE values and decreasing SLP from the south. Same for Monday but temperatures even higher. The threat of a breakdown is always there but in recent runs has been limited to over T200 hours. Guess nothing lasts forever unfortunately.

The theme in recent weeks of the model output is to overestimate the strength of the Atlantic against the high to our north so we shall see.

I hope the weather stays good for any plans you have, being a big storm enthusiast I'm happy to take them off Bournemouth 😃, hope the weather stays good for you.

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Fantastic hot and humid charts again from the gfs and ukmo!!ukmo looks even better than this morning with hot air getting slightly further north at with a more favourable angle of south east winds!!looks like high pressure aint going anywheere anytime soon and remain hot aswell!!

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Could be good for early hours on Tuesday if it came off 

  1. image.thumb.png.62a452d19be64b65fa0313bb91727fc3.png
  2. Also Sunday?
  3. image.thumb.png.db3a92581c61b27d3eaeab21ed387caa.png

image.png

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25 minutes ago, Alderc said:

Don't like

Don't like where its going as will breakdown HP and leave the door open for cooler more unsettled conditions ultimately. Also Saturday a pretty poor day generally away from the SE.

Odd post really, amazing how people can be so disappointed with a set of really very good charts. As for the breakdown, I can't see it coming quickly with the Atlantic so quiet. No signs of a proper breakdown anywhere near the reliable time frame. Here is the chart for next Friday from the GFS:

GFSOPEU12_225_1.png

Way out in FI and no real signs of the Atlantic encroaching on the UK.

Also I don't think the SE is going to the most favoured location for Saturday- I think that will be much further north and west, although it may well be warmer in the SE.

 

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3 minutes ago, Scorcher said:

Odd post really, amazing how people can be so disappointed with a set of really very good charts. As for the breakdown, I can't see it coming quickly with the Atlantic so quiet. No signs of a proper breakdown anywhere near the reliable time frame. Here is the chart for next Friday from the GFS:

GFSOPEU12_225_1.png

Way out in FI and no real signs of the Atlantic encroaching on the UK.

Also I don't think the SE is going to the most favoured location for Saturday- I think that will be much further north and west, although it may well be warmer in the SE.

 

Agree mainly, but this Friday looks a washout for this location

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4 minutes ago, I remember Atlantic 252 said:

Agree mainly, but this Friday looks a washout for this location

Yes Friday looks poor for most, very unlucky really in such a setup and with the jet so far north.

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89016F79-0B5F-4CB1-9590-BDA87471A4C1.thumb.png.e9200b8238f76b579875e8682043a6cd.png

 

this chart is just ridiculous....most dead Atlantic jet ive seen in a long time.

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2 minutes ago, mb018538 said:

89016F79-0B5F-4CB1-9590-BDA87471A4C1.thumb.png.e9200b8238f76b579875e8682043a6cd.png

 

this chart is just ridiculous....most dead Atlantic jet ive seen in a long time.

Well I hope the Atlantic stays dead. It seems to be in no mood to come and punish us just yet for this silly month!  

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Posted (edited)
17 minutes ago, Frosty. said:

The Gfs 12z is showing 28c for parts of the s / se on sun / mon and knowing how it tends to under cook maxima there is a chance of 30 / 31c.. maybe even a magical 32c 90f if the much warmer continental incursion lasts several days and even beyond that 25 / 27c for most of next week!..and it's not even summer yet!🌞🌡️ 

Could well be on @Frosty., local anglia forecast has said sunny and 28c here sun/mon....obviously they are backing away from the stormy predictions for this neck of the woods. I don’t think we will see a 30c, but you never know!

 

98D946EC-E495-4331-B175-D0FCBEC08AEC.thumb.png.1cb23428752aea394853efa96d864f08.png

Edited by mb018538
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Posted (edited)
43 minutes ago, Frosty. said:

The Gfs 12z is showing 28c for parts of the s / se on sun / mon and knowing how it tends to under cook maxima there is a chance of 30 / 31c.. maybe even a magical 32c 90f if the much warmer continental incursion lasts several days and even beyond that 25 / 27c for most of next week!..and it's not even summer yet!🌞🌡️ 

Yes, I think you are right to highlight the SE re temperatures, I think the risk of thunderstorms in Central regions and the SW is increasing with the 12z GFS.  

The CAPE chart for early Sunday evening is a belter for the potential of storms, which might set the temperatures back a bit in these areas. 

image.thumb.jpg.8b269a7fe29a519206d816df7f9856c4.jpg

Edited by Mike Poole
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Some charts from the ECM 12z, first T96, and the orientation of the high allows lower pressure to impinge from the south, and this creating the potential for thunderstorms late on Sunday:

ECM1-96.GIF?23-0

Moving on, here's the next few frames, as we go through a period of slack pressure near the UK while never really losing the heat, so warm periods, some humidity and potential for storms T120 to T192:

ECM1-120.GIF?23-0

ECM1-144.GIF?23-0

ECM1-168.GIF?23-0

ECM1-192.GIF?23-0

And from this dogs breakfast, a return to a high pressure ridge from the SW at T216:

ECM1-216.GIF?23-0

But this seems to be blocked off of moving over the UK at T240, lots to get through before day 10 though.  

ECM1-240.GIF?23-0

Having said that the retrogression possibility seems back on the cards with the 12 set more generally.

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