Uk General Convective Discussion & Forecasts, 28th August 2012>

[carl1980]

Local BBC mentioning thunder today and tomorrow î–

[Coast]

ESTOFEX only highlighting NW Scotland for today:

Storm Forecast

Valid: Mon 01 Oct 2012 06:00 to Tue 02 Oct 2012 06:00 UTC

Issued: Sun 30 Sep 2012 22:07

Forecaster: TUSCHY

SYNOPSIS

A constantly weakening upper level trough over Italy continues to move to the E/NE with further weakening anticipated. Scattered to widespread convection occurs in the area of influence of that trough and thunderstorm activity may spread far to the NE. A weak cold-core low affects the far E-Mediterranean/W-Turkey but the highest probabilities for isolated deep convection evolves to the east of our forecast area. Weak ridging affects parts of NE Europe, before another trough approaches NW Europe from the Atlantic.

Slight MLCAPE in that area later this afternoon:

Lapse rates quite high:

GFS says yes:

[Coast]

A mixed week coming up convectively, with a higher TT index, but I can't see a lot of thunderstorms coming out of it currently:

[Stuart]

yep look like a lots of showers and some storms mixed in this week

[AWD]

Heavy shower here currently. Went rather dark quite quickly.

[Karl83]

Heavy shower here currently. Went rather dark quite quickly.

It most certainly did. It was belting it down.

[itsnowjoke]

Just had a beefy shower here went rather dark too, i thought it was going to thunder.

[Andy Bown]

It most certainly did. It was belting it down.

Heavy shower here currently. Went rather dark quite quickly.

Lovely squall line running from Lyme Bay NE to Northampton and edging gradually E while heavy bursts run SW-NE along it. I wanted to

post earlier about it developing but couldn't access the forum.

[Liam J]

Very active band working through here atm, two rumbles of thunder heard and very intense rainfall in short bursts accompanied by squally gusts of 40-45mph out of no where. Nice

Excellent post W09, looking good for tomorrow, very windy to boot with gusts to 50mph likely. Shame I'm having a tooth extraction - Won't be able to enjoy the day, although it might take my mind off it lol

[Cloud 10]

Some interesting weather incoming it would seem.

[Cloud 10]

No electrical activity from that band that passed over but the rain was heavy/very heavy

which was impressive as normally showers/troughs lose much of their intensity

when coming over from the west.

[I Cumbria Marra I]

Had a little thunderstorm before! a few loud cracks of thunder and a few flashes, and i even seen my first fork lightning strike of the year, the rain was very very heavy and the winds must have been gusting near 60mph for a while, over in 15 minutes, but its the best i've had this year.

[Rainy]

3 cracks of thunder near here between 7.50 and 8pm this evening Bursts of heavy rain at the same time.

[ZONE 51]

I had posted in the Atlantic thread asking about tuesday, now i have read this ive got the idea of what's possible tuesday, so some active squally weather developing through tuesday and tue night.

Edited October 2, 2012 by ElectricSnowStorm

[Coast]

ESTOFEX have a repeat of yesterday pretty much:

Storm Forecast

Valid: Tue 02 Oct 2012 06:00 to Wed 03 Oct 2012 06:00 UTC

Issued: Mon 01 Oct 2012 22:36

Forecaster: TUSCHY

A level 1 was issued for parts of Croatia, Bosnia and Herzegovina and parts of Hungary and Serbia mainly for an isolated large hail and heavy rain risk.

SYNOPSIS

There is not much change in the atmosphere to talk about. The upper trough, which caused the deadly storm activity over parts of the W/C Mediterranean during the past few days finally loses its teeth. No real net motion to the NE is forecast while decaying over the N-Balkan States. An ill defined upper low over Turkey shifts a bit to the NE while also weakening. In fact, both features connect and result in a negative tilted trough, affecting most of SE Europe.

A major cyclonic vortex over far NW Europe won't move that much to the E, but attendant intense wind field at mid/upper levels already affects Ireland, UK and the North Sea with windy conditions forecast. Sporadic thunderstorm activity is possible with CAA atop the warm SSTs.

Some CAPE hotspots in there:

Upper level lapse rates OK in Scotland and Ireland:

BIG tornado possibility area today!

But for thunderstorms you need to head to Scotland or Ireland:

Or maybe the NW English coast and North Wales later:

[Nick F]

Valid: 02/10/2012 09:00 - 03/10/2012 06:00

Headline: ... THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FORECAST...

Synopsis

Low pressure system close to the N and NW of the UK will drive a cyclonic and showery SW'erly flow across the UK.

... IRELAND, SCOTLAND, WALES, N AND W ENGLAND ...

Cold pooling associated with upper low to the NW (sub -25c at 500mb in the NW) will spread SE across N and W UK today, increasing lapse rates. Heaviest showers and scattered thunderstorms with risk of hail most likely across the N and W of the UK where lapse rates will be steepest - particularly over coastal areas where warm SSTs will create extra low-level bouyancy.

Strong jet aloft and vort max spreading east across Ireland and Irish Sea areas this afternoon will increase vertical shear (40-50knts DLS and 20-25knts LLS) - so there exists a small risk of rotating updrafts with any storms in these areas - with slight risk of a tornado/waterspout and damaging winds - thus included a SLIGHT risk.

[DubWeatherAddict]

Wish i was out West in Clare right now!! Definite hook shape on it! :'( :'( :'(

[AWD]

Some very heavy PPN over Wales currently, stretching down into the SW approaches.

Could be an interesting feature for the SW and West Midlands later on.

[Chris W]

It's all looking quite interesting for today, the occlusion currently crossing Wales with some embedded convenction and more behind it by the looks of SW Ireland at the moment. Just starting to rain heavily in Birchwood after the rush hour burst this morning and a quite clear, sunny interim period.

[BornFromTheVoid]

Some flooding in Ennis, Co Clare.

[Liam J]

The wind is really ramping up here, A few gusts over 40mph since 2pm. Flash flooding over parts of Ireland from that very active area of ppn and embedded cells, heading right this way I think

Squally conditions moving eastwards, very intense rainfall over Wales right now as well - this front will continue to head eastwards.

Edited October 2, 2012 by Liam J

[Nick F]

12z Valentia radiosonde ascent looked fairly supportive of some stronger storms to develop in across Ireland/N Ireland this afternoon - particularly with additional warming of the lower layers and close to the coast where stronger updrafts develop from the contrast of the relatively warm SSTs beneath cold air aloft.

Marked dry slot at 500mb on the skew-t suggests instability enhanced. Speed shear aloft is pretty strong on the ascent - which aids pulling the downdrafts away from the updrafts, also backing of winds at the surface - which implies low-level shear along with low Lifted Condensation Levels (LCLs) increasing the likelihood of rotating updrafts into storms.

The possibility for a tornado or waterspout certainly there with storms over Ireland, certainly some interesting radar signatures that may hint at rotation. Dry air aloft also allowing strong winds aloft to lower towards the surface in any convective downdrafts too, so potential for damaging wind gusts. Excessive rainfall rates also appear to be causing some flash flooding issues where these storms pass.

[AWD]

Some heavy rain now in Cornwall & Devon moving ENE along the front.

[weatherobsuk]

Fairly sure there was a rumble of thunder here about 10 mins ago as moderate ppn passed on through, skies completely 8/8 with only dark patches giving away the embedded cells.

[Supacell]

Haven't posted for a while as there hasn't really been much convective interest for the last few weeks. However, later on today looks to offer a few possibilities. Nick has already mentioned N Ireland and I wouldn't be surprised to hear reports of some storms across NW England (Cumbria in particular) and parts of Yorkshire and NE England this afternoon/evening.

Unfortunately I don't think the convective elements will get as far as me here in Derbyshire, but plenty of rain again (its raining steadily now).

Edit: Just want to add Western Scotland and Wales into the areas that may get a rumble or three later

Edited October 2, 2012 by Supacell