Convective/Storm Discussion Thread 25/5/16 onwards

[Gordon Webb]

5 minutes ago, Hurricane Debby said:

Check this out - cars totally submerged in flash floods in Wallington !!!

 

http://www.lbc.co.uk/flash-flooding-in-london-sees-car-submerged-131842

 

just a teeny bit underwater

[Mesoscale]

The storm going towards St Albans was quite violent for a little bit. I am uploading footage now, although the main part missed me I got quite the light and audio show.

[Andy Bown]

45 minutes ago, Harry said:

These thunderstorms haven't abated the heat or humidity a jot. Just as warm and (unsurprisingly) even more humid outside. Still getting some awesome CGs across London (a +CG just then!)

As I'm sure you know Harry, it's a bit of a misnomer that storms clear the air. The local radio DJ said we could get a 'clear the air shower later' but that only really occurs once a cold front moves through and not when the storms occur within the warm/humid air.

[Nick L]

Just heard a distant cloud fart.

[Gordon Webb]

convectiveweather update

Day 1 Convective Outlook

VALID 06:00 UTC Tue 07 Jun 2016 - 05:59 UTC Wed 08 Jun 2016

ISSUED 13:49 UTC Tue 07 Jun 2016

ISSUED BY: Chris/Dan

UPDATE 13:49 UTC Added MDT to cater for existing extensive thunderstorm cluster over Cairngorms, with minor adjustments elsewhere. Overall, forecast remains as expected in issue from last night. Slim MDT removed from Wales since excessive cloud has inhibited surface temperatures to a certain extent, resulting with less thunderstorms here than initial expectations. Latest 06z EURO4 suggests an extension to the SLGT may be required over the north Midlands towards Merseyside for this evening. Likewise an extension of the SLGT may also be required deeper into parts of East Anglia - trends will continue to be monitored.

 

UPDATE 09:41 UTC Tweaks to SLGT and addition of MDT areas to highlight zones of better thunderstorm coverage / higher confidence

 

A complicated setup exists on Tuesday with various rounds / potential for thunderstorms through the forecast period. Synoptically, a plume of warm, moist air continues to advect north from the nearby Continent, capped initially by a notable warm nose aloft. However, it is likely that elevated convection will be ongoing Tuesday morning over the Irish Sea into eastern Northern Ireland / extreme SW Scotland, and perhaps also feeding into SE England from remnant overnight convection over France / English Channel - although the extent and amount of lightning activity with this remains questionable.

 

Otherwise, diurnal heating combined with low-level convergence (sea breeze and orographic forcing) with a shortwave trough nudging slowly NE-wards will allow isolated to scattered thunderstorms to develop through the afternoon and evening hours, forming into clusters along areas of pronounced wind convergence. DLS is rather weak in the main, leading to fairly disorganised convection, but given slow storm motion, relatively high MLCAPE (700-1100 Jkg-1) and 28-32mm PWAT, any storms that do develop could produce frequent lightning, local flash flooding with rain accumulations of 15-30mm in 1 hour, and hail up to 2.0cm in diameter. Converging low-level winds and rapidly rising updrafts may allow a couple of brief funnels / tornadoes to develop.

 

Storms will gradually decay through the late evening hours, although may still produce lightning well beyond 00z Wednesday across the East Midlands / Home Counties. The SLGT over the Home Counties may need to be merged with the SLGT over northern England if confidence continues to increase, along with perhaps the introduction of a MDT - trends will be monitored for this during Tuesday.

 

go http://www.convectiveweather.co.uk/

for the map

[SnowJoke]

Heard distant thunder from 2 strikes to the SE of Milton Keynes 10mins ago. Was picked up on lightning maps, then disappeared. Can confirm hearing thunder though.

[tomp456]

23 minutes ago, Gordon Webb said:

oh fine at the moment the lack of any storms is helping and I hope it just stays that way even if it don't I doubt it would be on the scale of what London has been and is seeing well hopefully anyway

Yep. Am well jel of those lucky souls on the continent as usual. If only the damn channel would evaporate in this heat!!

[The PIT]

Dead duck here as expected. Sheffield shield not even powering up

[STORMGUY]

We got hot sunshine here building up the heat for storms later.

[Mesoscale]

Here is the storm as it slid North/North East of me.

 

[Daniel*]

Blimey! 

 

[Chris K]

Couple of strikes picked up around North Devon/Bristol Channel?? A fair bit further SW than I expected, if true?

[stainesbloke]

Not much going on around Heathrow, some darker areas of cloud but dry after a brief downpour earlier. Very muggy and warm.

[Homerr]

1 minute ago, Mesoscale said:

Here is the storm as it slid North/North East of me.

 

Yeah sounded pretty awesome from here (Colonial Way if you know it) and some good CC lightning, heard it kick right off when it got to St Albans too. 

[Ben Sainsbury]

Just now, Chris K said:

Couple of strikes picked up around North Devon/Bristol Channel?? A fair bit further SW than I expected, if true?

I'm sorry to say but they are incorrect as no precipitation anywhere near.

[Tim Bland]

Storms becoming more widespread in Beds, Herts, Essex and Cambs now. Lightening Maps is playing up keeps removing strikes. This is more accurate http://en.blitzortung.org/live_dynamic_maps.php?mobile=1

[Gray-Wolf]

Well that was fun! I think the same storm had 3 goes at forming to my south ( Ripponden/Triangle?) and it drift off between Halifax and myself. Didn't touch the core so rain wasn't an issue but somebody will have got a soaking!! It has headed off toward east Bradford now and lost its thunder so it might be working itself up for take 4?

[lassie23]

Even Gordon Webb would have liked the thundery shower I just had, no rain, quiet thunder and distant lightning.

[PhilM1]

Interesting shape development to the southern cell in Wales on the 15:55 radar grab, but gone again 5 mins later. Looked like a nice little hook echo was forming to my very much uneducated eyes?!

[Nick L]

For what was on the radar that was laughably pathetic! 5 minutes of light rain and a few nice sounding rumbles.

[stainesbloke]

33 minutes ago, Hector the Convector said:

Yes indeed! They are in a different league aren't they....(ESTOFEX level 2!). One day i'll go chasing out there..has to be done! Anyhow back to the UK...some convection just starting to the east of my location..fingers crossed for south central later on

Maybe the 15 year imported thunderstorm drought will end tonight!? Looks interesting....

[Tempest]

No flashes and bangs here. Birds singing, people out with their lawnmowers happy as Larry, children playing, and me,sitting indoors cursing. Feels a little cooler and a covering of boring old cloud has arrived. Ho hum, when will i ever learn to never get overly hopeful  

[Hurricane Debby]

1 minute ago, Tim Bland said:

Storms becoming more widespread in Beds, Herts, Essex and Cambs now. Lightening Maps is playing up keeps removing strikes. This is more accurate http://en.blitzortung.org/live_dynamic_maps.php?mobile=1

Great link - thanks Tim

[Homerr]

Yeah much better thanks Tim

[Gordon Webb]

4 minutes ago, lassie23 said:

Even Gordon Webb would have liked the thundery shower I just had, no rain, quiet thunder and distant lightning.

yep probably