8th Aug 2011 - Storm/convective Forecast Discussion And Report

[Jane Louise]

More storms for some. Good luck all.

A large, elongated upper level low continues to be well established across the United Kingdom, with cold mid-levels. The trough axis will progressively move eastwards across the country throughout the morning hours, allowing a stronger, northwesterly flow to become established by the end of the day.

Synopsis:

MDT: CS + SE England SLGT: SW Wales, SW, CS + SE England, E East Anglia

Discussion:

The main area of interest will be along southern coastal counties, into SE England throughout the morning (0z-12z). Showers will continue from Sunday evening into the overnight period in the English Channel, these grazing southern coastal counties and being transported inland across Kent and the Sussex\'s in particular as the winds become more SWerly aloft across the eastern side of the Channel. Consequently, there is a continued risk of thunder and lightning from these, given ELT's as low as -30C and a few hundred J/kg CAPE. Given cold air aloft (typically -21C at 500mb) and predicated CAPE values, hail is likely in some of the showers. Weak DLS and LLS severely limits tornadic potential, although coastal convergence is likely to enhance the chances of a funnel developing.

Rising geopotential heights will slowly cause convection to decay and become increasingly shallower during the daylight hours. Consequently, lightning in the English Channel will becoming increasingly isolated, and should cease by early afternoon, despite diurnal heating.

During the afternoon, a shortwave trough is forecast to move southwards across southern Scotland and northern England, to the west of the wrap-around occlusion. This, combined with diurnal heating and topographic uplift, is likely to aid ascent and lead to convection. As a result, a few showers are expected by the afternoon, and with a couple of hundred J/kg CAPE and ELT's down to -25C locally, some sporadic lightning is possible. DLS of >30kts locally, combined with LLS <25kts suggests some organisation of convection is possible, and poses a risk of a funnel or weak tornado here.

Showers will become confined to eastern England during the evening, but with rising geopotential heights, convection should become shallower and as a result any lightning will become increasingly localised.

http://forum.netweather.tv/index.php?app=forums&module=post&section=post&do=new_post&f=7

[ZONE 51]

Another chance?wow! not seen any data. well this sound exciting

edit.. really i know whats about!

yes another interesting period coming up today, maybe some unexpected stuff about later, because this is where its hard to pin point where the convection may be most located, but the general areas are stated but you never know!

Edited August 8, 2011 by ElectricSnowStorm

[Coast]

ESTOFEX on holiday it seems again today. UKASF as above from Jane Louise here is the map:

Nothing current form TORRO or SkyWarn, here are a few indicators for the day:

Everything seems to be clearing East from now onwards

Scotland and the North has a little bit of potential:

I think the action of the last 24 hours is on it's way East now, with little of real interest for a few days now.

[Stuart]

Good luck all for today and for my last week here i no going to see any more

Edited August 8, 2011 by Stuart

[Harry]

Yeah going to be a quiet one nationwide I think today.

Certainly feeling very fresh this morning, the freshest its felt for quite some time now!

[P-M]

Good luck to everyone today but agree with Harry not looking too impressive today especially for here. Had a cracking day Saturday up here in the NE at one point 240 strikes per minute were being recorded according to some reports but to be honest today just feels very Autumnal a complete contrast. Very breezy and cold!

Edited August 8, 2011 by Paul-Michael

[Chris K]

Currently having a heavy-ish shower. But to be honest i'm not expecting anything else today. We were in moderate risk yesterday and pretty much got bugger all. So the fact i'm in slight risk today means it definately won't happen.

[Nick F]

ESTOFEX on holiday it seems again today. UKASF as above from Jane Louise here is the map:

I think the action of the last 24 hours is on it's way East now, with little of real interest for a few days now.

Can't really see much storm potential today - certainly not worthy going into any depth anyway. The cool northwesterly winds this morning have scoured away decent moisture and lapse rates aren't looking great ... most convection today therefore looks like being non-electrical - though an isolated rumble can't be ruled out, say, down the east coast of England this afternoon.

[Lauren]

Lot's of lovely clouds towering, but I very very much doubt a storm will happen.

Some fantastic looking clouds here.

[NO LONGER POSTING]

Well that was a hefty shower, didnt last long went very dark.. Seems to be building..Can see it on the radar..AND VERY STRONG WINDS ASSOCIATED WOW!

[Summer Sun]

Very heavy rain falling in Darlington at present. No Thunder.

[Adi F]

Really nice cloudscapes on the drive home. Now where are the storms after I misted everything yesterday!

[Harry]

Had some rather large convective raindrops earlier from a small dark cloud base.

Skies don't appear to be conducive to more organised cell development IMO.

[P-M]

Another weather warning out for more heavy rain in Northern Britain, is this likely to bring some localised thunder?

UKww Watch for Heavy Rain over Northern Britain

Issued Mon 08/08/2011 1300BST

Areas affected - Northern England, Northern Ireland and SW Scotland

Valid from: 0000GMT Wednesday 10th August 2011 - 1200GMT Thursday 11th August 2011

General evolution: A complex area of low pressure will being rain to parts of northern Britain. Fronts associated with the low will move east from western-most parts of the watch area. The rain band is then expected to move roughly SE, however the exact details remains uncertain at this time.

Weather- SW Scotland and the Western Isles are expected to receive the heaviest rain with rainfall totals of 50-80mm, more over upland areas. Strong winds are also expected with gusts to 40kts.

Localised flooding may occur especially in prone of valley catchment areas.

Please listen to local radio/television broadcasts for up to date information on travel conditions.

UKww will monitor this warning and update/upgrade when necessary.

Issued by PLJK for UKww, 1300BST 08/08/2011

Also Meto update on warnings http://www.metoffice.gov.uk/weather/uk/uk_forecast_warnings.html?day=3

[Neilsouth]

Had some rather large convective raindrops earlier from a small dark cloud base.

Skies don't appear to be conducive to more organised cell development IMO.

This ^

Poured it down earlier, big thundery drops but no thunderstorms

[lewis028]

Currently got a down pour here but no thunder, best we have had for a few weeks

[Lauren]

Torrential rain now.

[Summer Sun]

Heavy showers all afternoon here in Darlington, just heard a rumble of thunder as well.

[Harry]

What is it about that narrow region of this country that's been so conducive to severe activity over the past weeks?

[paul m]

What is it about that narrow region of this country that's been so conducive to severe activity over the past weeks?

I was thinking the same

[Joneseye]

What is it about that narrow region of this country that's been so conducive to severe activity over the past weeks?

It was like that way back on June 24th when I was up there for a wedding.

Might have something mean direction of the steering winds and local topography.. sounds good even if I am talking balony.

Edited August 8, 2011 by Joneseye

[seabreeze86]

Very heavy shower here but did not here any thunder, sky has looked very threatening all day.

[Snowstorm1]

Thundery Here

[sunny scunny]

A heavy shower at the moment here

[Summer Sun]

More heavy showers continuing to pass through the sky is very dark again now, rumbles of thunder at times though not as frequent as Saturday.