Out of curiosity could you explain why the boundary layer will not be an issue when the experts and charts suggest otherwise? 

What is it with these so called experts on these forums. There are no experts not even close. That word gets banded about again and again its just plain silly. 

There will not be a boundary layer issue  winds end of week lighter and more east southeast. You would not see uppers of 20c if there were boundry layer issues imho . Anyone really believing we will see uppers of 20c and 2m temps of just 24c or so in strong sunshine is plain crazy. Over and out.  

 

What is it with these so called experts on these forums. There are no experts not even close. That word gets banded about again and again its just plain silly. 

There will not be a boundary layer issue  winds end of week lighter and more east southeast. You would not see uppers of 20c if there were boundry layer issues imho . Anyone really believing we will see uppers of 20c and 2m temps of just 24c or so in strong sunshine is plain crazy. Over and out.  

Your reply confirms all I need to know.

Hello folks have noticed on weather for us that there appears a ecm  control and 50 member selection.

https://weather.us/model-charts/euro/c5defaf8681fe37cf1796186a2884a08/temperature-f/20190624-1500z.html

on the left there request switch members. Apologies if most of you knew that.

Ps 

Its been good discussion recently lets not spoil it. 

 

What is it with these so called experts on these forums. There are no experts not even close. That word gets banded about again and again its just plain silly. 

There will not be a boundary layer issue  winds end of week lighter and more east southeast. You would not see uppers of 20c if there were boundry layer issues imho . Anyone really believing we will see uppers of 20c and 2m temps of just 24c or so in strong sunshine is plain crazy. Over and out.  

Even latest met video talks about 32C potential in Bristol area by friday but only 16C in Newcastle.

N24 just had 30c for London Wed did not go further as Darren said its going to be a slightly changing situation.

 

Even latest met video talks about 32C potential in Bristol area by friday but only 16C in Newcastle.

N24 just had 30c for London Wed did not go further as Darren said its going to be a slightly changing situation.

 

 

Well i'll listen to the met office over the BBC any day 😉

https://www.metoffice.gov.uk/weather/videos

 Anyone really believing we will see uppers of 20c and 2m temps of just 24c or so in strong sunshine is plain crazy. Over and out.  

Perhaps one of the reasons the models are showing somewhat more conservative 2m temps in relation to the unusually high forecast 850s than one would expect is that this upcoming air mass will be unusually humid, and as we all know, water, be it in liquid or gaseous form, is much slower to heat than less watery forms such as solid earth or air masses that contain less water vapour.

 

Perhaps one of the reasons the models are showing somewhat more conservative 2m temps in relation to the unusually high forecast 850s than one would expect is that this upcoming air mass will be unusually humid, and as we all know, water, be it in liquid or gaseous form, is much slower to heat than less watery forms such as solid earth or air masses that contain less water vapour.

 

It will be partly due to this but I think there is also another reason.

The upper level and lower level winds are crossed. At the surface winds are northerly at the 850 level they may be southerly. Its quite bizarre and leads to an unusually low lapse rate.

A combination of very high shear and potentially a lower level stable layer could lead to some other interesting effects. The build up of CIN and high directional shear may make thunderstorms less likely but it also makes severe thunderstorms and supercells probably more likely.

Something to watch.

I'd add that I do think the GFS is underestimating surface temps, mostly because it always does in this kind of weather. However I don't think the idea of record breaking 850hpa temps and fairly mediocre heatwave level surface temps should not just be dismissed either. Its not all about what is going on at the 850hpa level.

The same is true for forecasting snow in winter, we all know that -8C can give occasionally give rain and +1C can occasionally give snow.

Soundings confirm what's going on. Complete wind reversal by the time you get to the 750hpa level. Temp at the surface, in this case is 20C which decreases a little as you move up the boundary layer and then sharply increases again to a maximun of what looks about 23C at about the 900hpa level. We have a very stable inversion layer near the surface.

This kind of profile is actually not all that uncommon in the states. Its actually quite dangerous. A stable layer near the surface can give rise to huge thunderstorms because the CIN allows CAPE to build to much higher levels than usual (thunderstorms don't just rain out).

Strong shear also makes supercell type conditions favourable.

Again this kind of thing makes thunderstorms somewhat less likely due to the highly stable layer near the surface but if enough CAPE can be built up to overcome the stable layer you can potetnailly get some quite severe storms.

 

What is it with these so called experts on these forums. There are no experts not even close. That word gets banded about again and again its just plain silly. 

There will not be a boundary layer issue  winds end of week lighter and more east southeast. You would not see uppers of 20c if there were boundry layer issues imho . Anyone really believing we will see uppers of 20c and 2m temps of just 24c or so in strong sunshine is plain crazy. Over and out.  

 

Soundings confirm what's going on. Complete wind reversal by the time you get to the 750hpa level. Temp at the surface, in this case is 20C which decreases a little as you move up the boundary layer and then sharply increases again to a maximun of what looks about 23C at about the 900hpa level. We have a very stable inversion layer near the surface.

This kind of profile is actually not all that uncommon in the states. Its actually quite dangerous. A stable layer near the surface can give rise to huge thunderstorms because the CIN allows CAPE to build to much higher levels than usual (thunderstorms don't just rain out).

Strong shear also makes supercell type conditions favourable.

Again this kind of thing makes thunderstorms somewhat less likely due to the highly stable layer near the surface but if enough CAPE can be built up to overcome the stable layer you can potetnailly get some quite severe storms.

Related a little to what you are talking about, but always a good idea to look at the direction of the isobars in relation to the 500hPa contours (I forget what the technical term of the 500hPa equivalent of surface pressure 'isobar' is ). 

Classic example for tomorrow night. High heights moving in from the near continent over the SE of the UK, but surface isobar direction running at a right angle to the 500hPa contour, meaning all is not as straight forward on that chart as may first appear. 

 

Related a little to what you are talking about, but always a good idea to look at the direction of the isobars in relation to the 500hPa contours (I forget what the technical term of the 500hPa equivalent of surface pressure 'isobar' is ). 

 

 

Classic example for tomorrow night. High heights moving in from the near continent over the SE of the UK, but surface isobar direction running at a right angle to the 500hPa contour, meaning all is not as straight forward on that chart as may first appear. 

Indeed. We are importing rather chilly air from the North sea near the surface, and importing very hot air from the continent further up.

I think its isohypse for geopotential height. I often use 'isopleth' though as that works for anything!

If it wasn't for the directional shear then the surface temps would be pushing up on the all time record (even despite the moist ground). If the ground was dry and we saw 25C I suspect 40C at the surface would be breached.

As it is I'm expecting something closer to 35C, impressive for the time of year but not record breaking.

The 850s though will almost certainly break some kind of record, as will thickness values.

I think its isohypse for geopotential height. I often use 'isopleth' though as that works for anything!

 

I'll keep this in mind! 

GFS is really cutting the temps now. Struggling to reach mid 20s anywhere during the week, with a 28C in London the highest come the weekend. Not much of a heatwave! And dewpoint in London of just 4C on Thursday. That’s about 20C lower than forecast a few days ago.

What's happened to Wetterzentrale? Haven't been able to get in there since about 7:30pm.

What's happened to Wetterzentrale? Haven't been able to get in there since about 7:30pm.

It seemed to go down. Back up now.

Again this kind of thing makes thunderstorms somewhat less likely due to the highly stable layer near the surface but if enough CAPE can be built up to overcome the stable layer you can potetnailly get some quite severe storms.

I know you are just talking potential, but it's very difficult to get t-storms on the time (Friday afternoon) of that tephigram, as the strong upper level ridging will kill off ascent.