Storm & Convective Discussion April 2016 Onwards

[Harry]

Keeping a cheeky eye on the weekend potential - nice for the warmth/dash of humidity if nothing else though it does seem likely there'll be some reports of thunder by the end of the weekend based on current projections.

Edited May 3, 2016 by Harry

[William Grimsley]

21 minutes ago, Harry said:

Keeping a cheeky eye on the weekend potential - nice for the warmth/dash of humidity if nothing else though it does seem likely there'll be some reports of thunder by the end of the weekend based on current projections.

I wouldn't get too excited for your area, most potential looks further west.

[William Grimsley]

Just been outside, in the sun and out of the wind it feels awfully warm and muggy! Summer is here, people!

[A.J]

52 minutes ago, William Grimsley said:

I wouldn't get too excited for your area, most potential looks further west.

too early to be making presumptions of where convective activity may or may not be, but taking that aside for a moment and actually looking at this morning's GFS for example, the output is rather underwhealming IMO for widespread thunderstorm activity...The west country, for example looks to plagued by cloud cover and showery rain from saturday onwards supressing surface based convection and the parameters for elevated storms look underwhealming.

Sunday looks better for home-grown convection for central and northern England, and then overnight monday into tuesday shows potential for elevated convection into the SE of England from the near continent.............This will all chop and change though as we move through the coming days

 

21 minutes ago, William Grimsley said:

Just been outside, in the sun and out of the wind it feels awfully warm and muggy! Summer is here, people!

warm and muggy?, I disagree....temps will max out around 15C today in the warmest spots, with highest dewpoint values around 5-6C, relatively low humidity............That will change as we head into the weekend as we pick up air from the near continent that has more moisture (from Biscay) mixed in 

[William Grimsley]

Ok, AJ.

5 minutes ago, ajpoolshark said:

too early to be making presumptions of where convective activity may or may not be, but taking that aside for a moment and actually looking at this morning's GFS for example, the output is rather underwhealming IMO for widespread thunderstorm activity...The west country, for example looks to plagued by cloud cover and showery rain from saturday onwards supressing surface based convection and the parameters for elevated storms look underwhealming.

 

Basically, that "showery rain" you mentioned is actually "thundery showery rain" as most of it will be imported along with quite a bit of mid level instability from France. 

5 minutes ago, ajpoolshark said:

warm and muggy?, I disagree....temps will max out around 15C today in the warmest spots, with highest dewpoint values around 5-6C, relatively low humidity............That will change as we head into the weekend as we pick up air from the near continent that has more moisture (from Biscay) mixed in 

Ok, maybe not warm and muggy, but out of the wind and in the sun it felt quite warm compared to recently.

Don't want to be off topic, but I'm surprised how much you're underplaying this...

Edited May 3, 2016 by William Grimsley

[A.J]

Just now, William Grimsley said:

Ok, AJ.

Basically, that "showery rain" you mentioned is actually "thundery showery rain" as most of it has been imported from France along with quite a bit of mid level instability.

Maybe not warm and muggy, but out of the wind and in the sun it felt quite warm compared to recently.

current modelling progs little mid-level instability.......mediocre potential energy, low lapse rates, and some mid level capping, far from ideal parameters,certainly for your region.....but I digress, very early days, but the signals are a tad underwhealming as it currently stands

[William Grimsley]

Just now, ajpoolshark said:

current modelling progs little mid-level instability.......mediocre potential energy, low lapse rates, and some mid level capping, far from ideal parameters,certainly for your region.....but I digress, very early days, but the signals are a tad underwhealming as it currently stands

Ah, ok. Well, if all else fails, we'll just have to go inland and hope to chase some surface based thunderstorms!

[A.J]

agree there......don't be disheartened though, what doesn't look great today can look much better tomorrow, that was my point, sort of.....the output can, and will chop and change so to rule out anything would be unwise 

[William Grimsley]

1 minute ago, ajpoolshark said:

agree there......don't be disheartened though, what doesn't look great today can look much better tomorrow, that was my point, sort of.....the output can, and will chop and change so to rule out anything would be unwise 

Hehe! You've got me excited now!

To be honest, maybe your signature is coming into play here...

Edited May 3, 2016 by William Grimsley

[weather09]

5 minutes ago, ajpoolshark said:

too early to be making presumptions of where convective activity may or may not be..

Agreed.  Just taking the outputs as they come at the moment as they're still getting a handle on upper (500mb) trough/ridge placement for the period in question, so finer surface detail, especially at this range, subject to the usual significant changes. UKMO-GM and ECMWF looking better in this regard, though, with GFS over recent days placing things more east.

What does look unlikely, however, is that conditions will be supportive of severe convective weather, given that mid-upper level jet winds look to be placed away from areas of interest, and instability not likely to be overly impressive if we're not seeing a real build-up of heat and moisture. 

Just quick thoughts on it anyway.  

[William Grimsley]

44 minutes ago, weather09 said:

given that mid-upper level jet winds look to be placed away from areas of interest, and instability not likely to be overly impressive if we're not seeing a real build-up of heat and moisture.

Really? I thought the upper level winds were south easterly!

[East_England_Stormchaser91]

5 minutes ago, William Grimsley said:

Really? I thought the upper level winds were south easterly!

Lack of sufficient wind shear looks to be the problem. Back in July last year, we had a raging jet surging up from Portugal and the Spanish plateau, we haven't got that here. Really is looking to be a messy setup and one which I'm not going to get my hopes up until I see something. 

Remember that bust early on last year Will? Lol. I don't want you wanting to sue the met office again  ! 

[weather09]

Yes, mid-level winds likely to flow S/SE'erly but with little increase in speed with height, and winds being unidirectional (no change in wind direction with height), means bulk shear profile not conducive to organised or severe convective weather. Lack of divergent jet winds also means forcing aloft lacking.  Ideally, you want SW/W'erly jet winds overlapping more backed winds at low-levels, then backing more at the surface, which would result in a favourable shear profile for severe storms. 

You can still get strong/severe storms even with weak shear if there's high instability and moisture available, but these storms not as long-lived or severe if they developed in a good shear environment.  Atm, doesn't look like we'll see either high instability or shear for period of interest.  

[William Grimsley]

@East_England_Stormchaser91, I remember that bust! I was quite annoyed that day, I remember receiving the keyboard I am currently typing this post on that day as well!

@weather09, I think I've got you now, so basically inland areas may well do better due to surface winds being from the east and upper winds being from the SE meaning more shear for those areas?

[Harry]

5 hours ago, William Grimsley said:

I wouldn't get too excited for your area, most potential looks further west.

To be fair, I didn't say that I was  I am more looking forward to the first proper heat of the year with some thunder potential mixed in. 

[Bolt from the Blue]

It's still early days, not getting my hopes up yet 

 

 

OK, maybe a tiny weeny bit... 

[NO LONGER POSTING]

Just a reasonable guess it could get busy in here in the next 2 weeks

 

With a lot of 

And maybe some 

 

Depends what floats your boat..

[Spikecollie]

Looking good here in France with temperatures building nicely and some instability. CAPE into the 1400s progged on Météociel, but it can all change so easily. Meanwhile I have a long weekend off work from Thursday to Monday and I'll be using the warm afternoons for nice long cycle rides. And when I fly back to the UK on Thursday week I could get some nice cloud watching in too...I hope everyone gets what they want 

[William Grimsley]

Just watched the latest BBC weather forecast, I think thunderstorms are on the cards for us from Friday onwards with the risk increasing through next week! Cheers everyone!

Edited May 3, 2016 by William Grimsley

[Paul]

Locking this one - new thread looking ahead to the upcoming storm risk later in the week and into the weekend