A lot of hot air?

[xmetman]

The Met Office seem to be in raptures about the temperatures this coming Bank Holiday down in England.

The high temperatures are certainly not going to happen everywhere, and ICON doesn't seem a little lower than the 32°C forecast by them for Sunday over London.

[xmetman]

I notice that the Met Office amended the original story the next day which promised 32°C for Sunday and 33°C for Monday but forgot to edit the video though. As far as I can see the thrust of the warm air, as in the other two hot spells, is further east.

[xmetman]

Another day another press release...

Todays looks to be a toned down version of Wednesday's.

They sounded rather confident on Wednesday that we would see a record breaking 33°C in the southeast now they don't seem so certain.

If you listen to the video it still contains a slight ambiguity in what "meteorologist" Alex Deakin and the "Chief meteorologist" Andy Page think the highest temperature will be on Sunday, is it going to be 30°C or 32°C?

It all begs the question of haven't the Met Office got better things to do with their time than provide headlines for the tabloids?

As usual substitute "except for those in the north of Scotland" when you see trite phrases such as:-

1. "for most of us"
2. "for many" 
3. "generally"
4. "...the vast majority"
5. "...not everywhere"

[Julian Mayes]

The more heatwaves are 'toned down' the better as far as I am concerned, residing as I do in the lower Thames valley cauldron.  I must move. 

Before I do that, I see that the warmest obs site at 14Z was Hull (East Park).  27.4C, even higher than the usual suspects of Cavendish and Heathrow.  I once looked on Google streetview to find the met site there but it was hidden somewhere behind a building and the childrens' playground.  By displaying the Hull temp on a forecast chart, it does make Yorkshire look warmer than  most of it is - on most days. I'm not sure the public always realise how much temps vary in short distances.  

Julian  

[Freddie]

Different scenario this time around, Bruce (comparing the two heatwaves).  Last time, there was more cloud (and mid-level convection) than the models picked up on.  The plume of warmest air was correctly forecast - it was the increase in mid-level moisture (and consequently cloud that lowered the amount of energy available for insolation) where the models were in error.  This time round the dynamics of the trough disruption are being struggled with - as the models tend to with the fine details.  The disruption in the latest runs occurs sooner and further north, which leads to the southerly flow that pushes the warm air northwards not lasting as long, so the warm air makes greater progress northwards to the east of the UK, as you point out.

The disruption may not pan out exactly as the models are currently suggesting, so there is the possibility that it may be warmer or cooler depending on the details.

Regarding your point about "30 or 32": I think the best way to look at it is that most will see 30 (in the area of the 30 symbol), with a few favoured spots getting 31-32.  It would definitely be misleading to put a 32 on that chart if it is not the "general" maximum for that area.  It's down to the presenter to mention the favoured spots.

--
Freddie
Dorrington
Shropshire
115m AMSL
http://www.hosiene.co.uk/weather/
Stats for the month so far: https://www.hosiene.co.uk/weather/statistics/latest.xlsx

[Metman2012]

Bruce, you forgot:

6 "For the many, not the few"

or is that something else....?

[Brian Wakem]

Arpege 12z Tmax for BH Monday:

[xmetman]

Up to 4°C warmer across parts of London than at the same time yesterday...

[Julian Mayes]

Yes it is rather warm - thankfully the house has not yet heated up, helped by cool night last night here too.  

Two 12Z temps that are high in relation to local averages - maybe some downslope warming implicated in each case - Loftus and Gogerddan (Aberystwyth) - both 26.8C.  SSE flow at each site.    Aberporth at 25C having one of its rare outbreaks of warmth! 

Thankful for the earlier sunset at this stage in the year compared to that of early-season heatwaves. 

Julian  

[Freddie]

On Friday, 23 August 2019 15:58:52 UTC+1, Freddie wrote:

the dynamics of the trough disruption are being struggled with - as the models tend to with the fine details.  The disruption in the latest runs occurs sooner and further north, which leads to the southerly flow that pushes the warm air northwards not lasting as long, so the warm air makes greater progress northwards to the east of the UK, as you point out.

The disruption may not pan out exactly as the models are currently suggesting, so there is the possibility that it may be warmer or cooler depending on the details.

Disruption handled differently by today's runs, with much slower forecasted motion of the associated upper vortex.  Instead of trundling across southern UK over the second half of the weekend it is now forecast to stall south of Ireland and then move SSE into Biscay as a shallow feature.  This of course means that the warm air will last longer, as is highlighted by the current forecasts - with talk of the southeast remaining very warm or hot until Wednesday.

As is the nature of trough disruptions, the dynamical progression (and consequently the forecast) will probably change again!

[xmetman]

Freddie - I bow to your superior knowledge of synoptic developments, but I can't help but think even with your training that perhaps you (and perhaps Julian with his Meteogroup connections) have access to the Met Office SR part 2 (that's if it still exists). It maybe that I just spend far too much of my time looking at surface charts and not the upper air and that fast moving ribbon of air high up in the atmosphere!

[xmetman]

https://twitter.com/i/status/1165253137244012544

[Brian Wakem]

Looks like a max of 27.9C here after a rather cool 8.2C min.  Tomorrow we start from much higher so easily over 30C I think.

-- 

Brian Wakem

Lower Bourne, Farnham, Surrey

http://www.brianwakem.co.uk/weather

Live obs @ 15:48:28 : 27.7C, DP 12.1C, RH 38%, 0.0 mm

[Freddie]

On Saturday, 24 August 2019 14:31:50 UTC+1, xmetman wrote:

Freddie - I bow to your superior knowledge of synoptic developments, but I can't help but think even with your training that perhaps you (and perhaps Julian with his Meteogroup connections) have access to the Met Office SR part 2 (that's if it still exists). It maybe that I just spend far too much of my time looking at surface charts and not the upper air and that fast moving ribbon of air high up in the atmosphere!

SR part 2 no longer exists :-(

It is my training that I use to try and work out what's going on and why a forecast for a particular day is likely to go off course.  I use these rules:

• never trust a single model
• never trust a single model run
• if a forecast looks "odd" for a certain situation then try and work out why
• if a forecast isn't going to plan then try and find out why

I use charts and data available to all off the Internet.  I do it this way because it is challenging and keeps me thinking and furthering my knowledge.  It's not every day that I have the time to do it, but I do it whenever I can.

I love all the stuff you do with surface data - it is very useful, and was much missed when you were on your sabbatical.

I also love that you challenge the weather forecasting organisations - but if I think you're being unfair I will say so (if I have the time).

That "fast moving ribbon of air" is part of the troposphere, and it all has a bearing on the weather we experience down on the surface.  You do need to be aware of the troposphere as a whole when you are considering a forecast.

[xmetman]

[xmetman]

It looks like the initial forecast of an extreme maximum of 33°C is on the cards judging by the temperature differences with yesterday at 11 UTC this morning. 

[xmetman]

A lot of hot air around at the moment and some of it >90°F.

[Brian Wakem]

Max of 31.2C (88.2F) here.  Only the 4th hottest day of the year though.

-- 

Brian Wakem

Lower Bourne, Farnham, Surrey

http://www.brianwakem.co.uk/weather

Live obs @ 16:48:49 : 29.4C, DP 13.2C, RH 37%, 0.0 mm