Model output discussion 14/04/18

[Summer Sun]

19 minutes ago, Quicksilver1989 said:

Yup GFS forecasting 32C for next weekend and ECM 35C, could be a real scorcher of a week coming up.

You could easily add 2 or 3c on GFS given its tendency to underestimate

We could be really close to the all-time June record

[Djdazzle]

2 minutes ago, East_England_Stormchaser91 said:

2006 came pretty close, just didn’t find a way to persist and the setup got totalled by the Atlantic coming back in. 

Yes it was a pity about the August that year.

[Singularity]

So the GFS 06z takes a step toward the ECM 00z in shifting the Iberian low a little closer to our shores.

Close enough, in fact, for a few thunderstorms to affect the SW tip of Cornwall very briefly midweek. 

This highlights the balancing act we play, though with GFS' over-enthusiastic instability parameters, we may have a bit more wiggle room between the hottest draw of air and destabilisation than that model run implies.

I can see a risk emerging of the pressure pattern slackening off early the following week while some seriously toasty air is in place. That's a recipe for extreme high temperatures but also severe thunderstorms should the ridge weaken sufficiently. In my book, that's some dangerous weather, toward the upper limit of what this country can experience - so something to keep a close eye on. Personally, my view switches from 'looking forward to the test' to 'concerned about the impacts' when wide areas are in line for temps of 32*C+ with local hot spots in the mid-30s.  Currently, only GEM gets all that close to such a level of heat, but you know what, I am always making lots of notes during periods of highly anomalous weather, and they tell me it's been closer than ECM and GFS with the maximums during the majority of very warm or hot spells in the past few years.

What a time to be following the weather prospects closely .

[booferking]

NAVGEM really going for it

[Interitus]

Regarding ECM 850 temperatures - they are by and large not representing warm air advection but rather more dry air subsidence under the anticyclone - therefore the lapse rate is reduced and the surface temperatures are not as high as estimated (-see the ECM charts on weather.us as evidence - very warm or even hot but temperatures not widely into the 30s never mind record range)

[Northwest NI]

3 minutes ago, Interitus said:

Regarding ECM 850 temperatures - they are by and large not representing warm air advection but rather more dry air subsidence under the anticyclone - therefore the lapse rate is reduced and the surface temperatures are not as high as estimated (-see the ECM charts on weather.us as evidence - very warm or even hot but temperatures not widely into the 30s never mind record range)

Anything between 22 and 28 will do.

[Man With Beard]

30 minutes ago, Interitus said:

Regarding ECM 850 temperatures - they are by and large not representing warm air advection but rather more dry air subsidence under the anticyclone - therefore the lapse rate is reduced and the surface temperatures are not as high as estimated (-see the ECM charts on weather.us as evidence - very warm or even hot but temperatures not widely into the 30s never mind record range)

It's important to mention that the ECM temperatures on weather.us are usually down as much as 3C on actuals - today a good case in point, most places already 1-2C up on the predicted maximums, with two hours of heating still to go. I think this morning's ECM, if verified of course, would mean 5 days at 30C or a bit above in places.

[Singularity]

30 minutes ago, Interitus said:

Regarding ECM 850 temperatures - they are by and large not representing warm air advection but rather more dry air subsidence under the anticyclone - therefore the lapse rate is reduced and the surface temperatures are not as high as estimated (-see the ECM charts on weather.us as evidence - very warm or even hot but temperatures not widely into the 30s never mind record range)

True that, but you can still add at least a couple of degrees to those for typical error adjustment, which puts quite a few near or at 30 (in fact most of England at the weekend - and Sunday already has some 30s in place... but that’s because we do see a draw of heat at that time).

If it wasn’t for the very dry ground I’d side more with mid-high 20s tops prior to any hot air imports.

 

Ha, MWB has just beat me to it. Kudos!  

[mb018538]

Good points made - you do feel that we will exceed 30c though If those charts come off, advection or subsidence....it’s damn hot! I also don’t see anything like 35c appearing, but we will see....a slight switch to a more southerly feed after 5 days of heat could deliver something.

[Mike Poole]

Bonkers chart of the day:

[Djdazzle]

6 minutes ago, Mike Poole said:

Bonkers chart of the day:

Clearly a cold outlier . . .

[Methuselah]

Anyone-else ever wonder whether one or two of the more, shall we say, least-realistic of the models ought be ordered to take 'early retirement'?

Edited June 22, 2018 by Ed Stone

[Mokidugway]

Not shure about this but does soil moisture content and recent months of soil transpiration affect surface temperatures ,dry soil hotter weather ??

[tcc]

1 minute ago, Mokidugway said:

Not shure about this but does soil moisture content and recent months of soil transpiration affect surface temperatures ,dry soil hotter weather ??

Yes it does, that's what (IIRC) what caused us to have the record temps and heat (and in France) in 2003. 

[Djdazzle]

15 minutes ago, Ed Stone said:

Anyone-else ever wonder whether one or two of the more, shall we say, less-realistic of the models ought be ordered to take 'early retirement'?

Like GFS!

[Bogman]

Are we allowed to poo-poo what the charts are showing, completely ignore them, then comment about how none of it will happen, how the charts are rubbish, and that the polar opposite will happen?

 

Or is that only during winter?

 

Anyways, roll on the summer. Been lovely down here the past few weeks.

Long may it continue. Beautiful.

[Northwest NI]

30 minutes ago, Bogman said:

Are we allowed to poo-poo what the charts are showing, completely ignore them, then comment about how none of it will happen, how the charts are rubbish, and that the polar opposite will happen?

 

Or is that only during winter?

 

Anyways, roll on the summer. Been lovely down here the past few weeks.

Long may it continue. Beautiful.

Excellent use of the word “polar”

[Bogman]

27 minutes ago, Northwest NI said:

Excellent use of the word “polar”

 

[Captain Shortwave]

Probably worth pointing this out, yesterday the UKMO was probably the best output for those who wanted the highest temperatures.

Well to show how far things have come over 24 hours, here is todays day 5 chart which is for Wednesday compared with yesterdays day 6 chart.

   

That modelling of the cold pool to our east has shifted towards something much weaker and as a result the ridge through the UK is stronger. The result lighter and more variable winds and probably higher temperatures as the heat to our south is allowed to build northwards without much resistance.

[Craig84]

12z UKMO is an absolute cracker at 120

[Craig84]

And at 144 many locations will be sailing through the 30 degree mark surely

Edited June 22, 2018 by Craig84

[shaky]

Good grief what a start to the 12zs!!gfs a peach up to 132 hours so far and the ukmo is basically being put in a furnace!!surely cant upgrade more than this can it!!

[Fourty Point Three Degrees]

Hints in the models of a return to more of an Atlantic coming 2nd week of July. Hopefully just a blip. We'll see. 

[BruenSryan]

9 minutes ago, shaky said:

Good grief what a start to the 12zs!!gfs a peach up to 132 hours so far and the ukmo is basically being put in a furnace!!surely cant upgrade more than this can it!!

It's like the Beast from the East all over again.

7 minutes ago, 38.5*C said:

Hints in the models of a return to more of an Atlantic coming 2nd week of July. Hopefully just a blip. We'll see. 

Why are you looking out that far? Jeez. We have enough uncertainty out to Friday 29th or Saturday 30th June. Never mind the second week of July! Enjoy it whilst we have it.

Edited June 22, 2018 by BruenSryan

[mb018538]

850s in excess of 16c for a large chunk on Wednesday and Thursday....expect 30c to be breached folks...