Convective Storm/Discussion thread - 11/06/16 onwards

[Polar Maritime]

Today's cape values for later this afternoon.

 

[dec10snow]

Had a heavy shower about 40 minutes ago here, looks like there's a larger lump working its way down toward me now also... Let's hope for a good day!! 

[Norfolk Sheep]

Another four rumbles of thunder this week, I am being spoilt! However my June rainfall total is getting silly - 84mm. 

[Windblade]

21 hours ago, Sainsbo said:

If you have a trigger and the instability is there then I think the main ingredient you need for more organized/multi-cellular storms is shear to help separate the updraft from the downdraft.

 

Every now and then it looks like the sun is trying to pop out here, but then it disappears again! Nothing on the radar around here as of yet, but still very early in the day. Haven't been very lucky so far this week so maybe today is the day 

Ah, thanks for explaining. I wasn't quite sure how multi cell storms form vs pulse storms. Makes more sense now. Thank you.

Edited June 17, 2016 by Windblade

[Delka]

8 minutes ago, Norfolk Sheep said:

Another four rumbles of thunder this week, I am being spoilt! However my June rainfall total is getting silly - 84mm. 

Up to 47mm on the coast up here, looks like you've been getting a bit more activity

[Freeman]

Morning All,

I wanted to upload these yesterday but the website wouldn't have it.... either way here are some lovely storm clouds passing Peterborough at around 17:15pm.

Enjoy!

[Azazel]

looking at the charts for today, i would highlight the following as areas of possible interest today

 

Edited June 17, 2016 by Azazel
wrong file!

[Nick F]

Emphasis for storms shifting south today, I favour areas south of M4 and London seeing some nasty storms later, convergence indicated towards English Channel coasts - so expect funnels or even brief/weak tornadoes. 

Here in south London, just a few distant rumbles heard so far this week from storms that were across west London yesterday evening, so hoping for some storms overhead today being the last day of this thundery period.

Anyway, storm forecast for today:

Storm & Convective Forecast

Issued 2016-06-17 08:21:43

Valid: 17/06/2016 06z to 18/06/2016 06z

CONVECTIVE / STORM FORECAST - FRI 17TH-JUNE-2016

Synopsis

Upper low that's been over the UK these past few days will drift slowly east onto the near continent by Saturday morning, while a ridge of high pressure over the N Atlantic builds in from the west. At the surface, a shallow area of low pressure centred across the far SE of England at 06z will drift E over the Low Countries today. A deeply unstable airmass will hang on across southern Britain today, bringing another round of scattered diurnally-driven thunderstorms, while cooler, drier and more stable airmass moves in from the NW across central and northern Britain.

... SE WALES, S ENGLAND and E ANGLIA ...

Fairly steep lapse rates atop of stagnant moist surface airmass across southern Britain today, characterised by dew points of 12-14C / temps reaching the high teens, will become unstable to surface heating where sunny spells develop ... triggering heavy downpours / thunderstorms. Lack of vertical shear again today will mean storms will mostly be pulse-type, i.e. downdrafts will not be tilted away from the updraft and so downdrafts will evenually suffocate storm updrafts and kill the storm, while new storm updratfs pop-up nearby.

However, models indicate 300-900 j/kg CAPE, which combined with weak winds aloft will favour slow-moving intense burst of rainfall that will lead to flash-flooding and treacherous driving conditions in places. So have highlighted a MARGINAL risk for the flooding. Storms may also be accompanied by isolated hail up to marbe-size, gusty winds and occasionally frequent bouts of cloud-to-ground lightning.

Wind convergence is indicated by models and current obs across southern coastal areas - so here we could see stronger updrafts rotate to create funnel clouds or even brief/weak tornadoes.

Issued by: Nick Finnis

Edited June 17, 2016 by Nick F

[tomp456]

3 hours ago, Supacell said:

Most likely won't verify but GFS 00z is a stonker of a run for late next week into the weekend. Nice to see the storm porn though

This map will turn out to be at least partly accurate.....over France! 

[Spikecollie]

47 minutes ago, tomp456 said:

This map will turn out to be at least partly accurate.....over France! 

I actually hope it doesn't get to the point when I can't CB dodge and get out on my bike. Those CAPE values are pretty good for June. Nearly risked it just now, but they're building too fast to go for it and I've got a bit of a stomach upset so it's probably as well. One of my neighbours jokingly refers to me a the "lapin crétin" when I set out. If storms are ever annoying - how could they be!!! - it's constantly losing the power here that's bit of a pain.

[andymusic]

Tropical downpour here and thunder

[Spikecollie]

We're off too!!!

[weirpig]

Dry here at the moment  mind you after the events of yesterday  im not to bothered 

[William Grimsley]

Had a brief thunderstorm to the SW yesterday evening! Convection is already kicking off, so could be another interesting day for this area again!

Edited June 17, 2016 by William Grimsley

[andymusic]

a little more thunder - seems we have an early start to proceedings here today

[Windblade]

Had light drizzle here this morning. Very overcast and cool. This needs to clear quickly if we are going to see anything.

 

EDIT - Looks live eastbourne, margate and new romney have all got nice storms already.

Edited June 17, 2016 by Windblade

[Stormyking]

Well hello there Mr Cumulus, breaking threw that cap rapidly, Cowes under a torrential shower, and stuff developing in the solent too

[William Grimsley]

Can we just take a minute?! Just imagine if this pulled off and the cap was broken, my word!

[Neilsouth]

Thunderstorm here! - Ashford way

[Spikecollie]

Great diurnal heating here in Limousin, France. Went from 12c to 23c in two hours. We had total fog this morning but it cleared. So weird...

[Wivenswold]

Nearby strikes but no thunder heard here yet. Looking good for Tendring/Ipswich. 

[Windblade]

5 minutes ago, Neilsouth said:

Thunderstorm here! - Ashford way

Cool. Happy for you . Hopefully the convection will expand a little further north east so I can get in on the action too! I can see small patches of blue now.

Edited June 17, 2016 by Windblade

[SenlacJack]

Distant thunder audible here in St Leonards -on -Sea from that Eastbourne thunderstorm. Skies here are looking very stormy.

[Super_Uwe]

Waiting to see what happens again today! Had our first proper storm down in this part of the South Hams (Kingsbridge area) yesterday which was nice, a couple of very close strikes too. Been a very long time since we have had anything like it I can tell you!

Some of the villages like South Pool and Frogmore had some quite nasty flash flooding. I did manage to get a fairly nice shot yesterday; the heaviest rain really didn't shift a great deal for a good couple of hours. So Armageddon in one spot and pretty nice weather a couple of miles away as you can see from my pic!

[Windblade]

2 minutes ago, Super_Uwe said:

Waiting to see what happens again today! Had our first proper storm down in this part of the South Hams (Kingsbridge area) yesterday which was nice, a couple of very close strikes too. Been a very long time since we have had anything like it I can tell you!

Some of the villages like South Pool and Frogmore had some quite nasty flash flooding. I did manage to get a fairly nice shot yesterday; the heaviest rain really didn't shift a great deal for a good couple of hours. So Armageddon in one spot and pretty nice weather a couple of miles away as you can see from my pic!

That's beautiful. The best thing about being down your way is the road network that actually allows you to chase (unlike up here with speed cameras, potholes, speedbumps and traffic lights galore). I'd love to live down there - I'd be out chasing at every opportunity!