Uk Convective General Discussion & Forecasts, 17th July 2012>

[Chris.R]

I'm near newbrighten atm and it's dry here. Can see a very mean looking line of showers from here to south liverpool. Looks good but missing me as usuall

[carl1980]

Heavy shower about 15 mins ago no thunder though .

[cyclonic happiness]

We haven't had a night time storm here in at least 15 years now, yet during the 80's we had seemingly dozens of them?

[East_England_Stormchaser91]

We haven't had a night time storm here in at least 15 years now, yet during the 80's we had seemingly dozens of them?

Possibly an annoying shift in the upper atmosphere, as someone posted a clear demonstration of the UK as a whole getting lack of the cracking storms we used to get,due to the altering of the jet stream. Everything just seems to be diverted totally away from us now as the evermore frustrating jet stream grabs the storms and chucks them over Central Europe, instead of the strong Spanish plumes that pushed them directly N from Spain/France slap bang over us. I blame the Greenland high + the fast melting of Arctic ice.

[Stuart]

Synopsis:

Large upper trough with cold mid-levels (~-24C at 500mb) with the jet on the southern flank over northern France. A day of widespread convective showers is expected across much of the British Isles.

Discussion:

Widespread showers and thunderstorms are expected as ~700J/kg CAPE develops in response to rising LSTs. Rather weak shear will mean convection will be poorly organised, with a series of \'pulse-type\' storms expected. There is sufficient dry and cold air aloft for hail in many of the stronger cores, with a local event >2.5cm in diameter possible.

While PWAT are <20mm generally, slow storm motion and \'shower trains\' may give rise to flash flooding locally.

Showers will generally decrease in coverage during the evening hours as daytime heating subsides, but are likely to continue overnight in places due to the proximity to the upper trough.

... SW, CS & SE ENGLAND ...

Most models simulate a W-E line of convective showers/storms through the morning and first half of the afternoon, before weakening and shifting eastwards by late afternoon. With such CAPE values and close proximity to the jet, providing some speed and weak directional shear, cells are likely to be better organised here with more frequent sferic activity. Such (albeit weak) shear will also increase the chances of rotation, resulting in a funnel or weak tornado event potentially.

... EAST ANGLIA ...

During the afternoon, there are signs that convection may become better organised into a NE-SW oriented line, with the most mature phase (in terms of sferics) likely to be over central and eastern parts of Suffolk and Essex, and subsequently clearing over the North Sea later. Slight speed shear here also increases the chance of a funnel or weak tornado.

http://www.ukasf.co.uk/storm-forecasts/196

[Weather-history]

Lets take the time to remember 'El Brumo', the best tornado to have ever stuck Britain 7 years ago today.

[Staffordshire]

Hey does antone have any radar returns/charts from 23rd sept 2010? ive seen on youtube there wasa big storm around these parts, thanks!

[Will Padz]

Hmmm is Sunday going to disappoint too?

Someone must get something out of this lot even if I don't!

Central England toward EA again then?

Rizzle kicks playing at quex park tomoz maybe they'll get the just lightening bolt.....

[Keraunic]

[Central England toward EA again then?] Oh I do hope so. Just one nice MCS preferably at night.

[Robbie Garrett]

Was in Manchester today, Manchester Airport to be specific. Had two fantastic Thunderstorms to add to my yearly total, as I got caught out walking in them and got saturated... felt well nice.... How about that!!

[Keraunic]

Was in Manchester today, Manchester Airport to be specific. Had two fantastic Thunderstorms to add to my yearly total, as I got caught out walking in them and got saturated... felt well nice.... How about that!!

Lucky you. It's a wonderful feeling going out in the rain and thunder. And two in one day; not bad going these days.

[legritter]

morning all ,lack of sleep sent me to bed early last night ,just [5 .30 am ] got woke up by mother nature .then as i went out our back for my first fag 5..40 am a brilliant thunder bolt followed by 5min of realy intense rain ,still raining hard , seems to be moving in from the west or slightly south of west , not much showing on radar so must be forming quite quickly ,just noticed on current fax chart a trough moving east today ,clearing the east later . temp outside is quite chilly .look foreward to posts today as could be very interesting for local areas later today once the sun gets in on the act .intensity now dropped but sky out west looks dark .certainly a day of radar watching cheers legritter ,

[Nick F]

A lovely sunny morning with blue skies here in west London, but already can see signs of convection to the S and SW. Should be some photogenic cloudscapes today in the clear Pm air, though not expecting anything spectacular on the storm front given lack of heat and moisture in these cool polar flows.

Storm forecast for today:

Valid: 29/07/2012 07:30 - 30/07/2012 00:00

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

Synopsis

Deep upper and collocated surface lows close to Scotland drive an unstable cyclonic flow across the UK on Sunday.

... SCOTLAND, IRELAND, ENGLAND AND WALES ...

Upper low/cold pool across the UK, with 500mb temps between -20 to -25C, will create steep low/mid level lapse rates during Sunday. The atmosphere will destabilise quickly this morning from the west aided by the passage eastwards of a short-wave trough. Already sferics have been detected across SW England this morning. Surface heating will further increase coverage of thunderstorms by late morning, though emphasis for storm development across England and Wales will tend to shift towards central and eastern areas during the afternoon with continued passage eastwards of shortwave trough.

With weak vertical shear and rather meagre dew points, no severe weather is anticipated, with storms tending to be well scattered, generally dis-organised and short-lived, though some organisation of storms is possible across southern counties where stronger upper winds will be present. Storms maybe accompanied by hail and gusty winds, with a slight risk of localised flooding.

Issued by: Nick F - Forecaster for Netweather

[SteveB]

Lots and lots of rain last night and this morning, and I heard one rumble of thunder.

30.2mm so far, and that pushes the monthly total to over 200mm

[Chris.R]

Could see one of the storms over manchester yesterday from the wirral, a huge CB with an anvil. It looked as if the cells developed as they headed inland but were just showers in liverpool. There was some great rainbows and cloudscapes though with the sun shining on the Liverpool waterfront against the dark clouds. I walked from Leasow to Seacombe along the coast and it was dry and sunny, but just over the water it was chucking it down!

[gottolovethisweather]

I find it interesting that despite there being a decent risk of storms today for the region, there's not many members from the south-east chatting away about MCSs and "imports"...which, by the way, arise via an entirely different setup than today's.

I put it down to a lack of input from 'select' members, whose words are heeded more than others'.

Did I just say that?

Mr. weather09, aren't you a select member too, surely with your very detailed knowledge of all climate parameters, your words are as invaluable as anybody elses. I'll personally heed your words for today, so do you kindly have a further update for us?

Some activity (unfortunately no sferics) on the radars already, with parts of Bristol and Somerset down south in line with parts of Manchester, Bradford and Leeds looking good further north right now.

Cheers

gottolovethisweather

Edited July 29, 2012 by gottolovethisweather

[Flash Elvis]

Did nobody in NE Essex see the lightening about 11.30pm last night?

[Supacell]

Mr. weather09, aren't you a select member too, surely with your very detailed knowledge of all climate parameters, your words are as invaluable as anybody elses. I'll personally heed your words for today, so do you kindly have a further update for us?

Some activity (unfortunately no sferics) on the radars already, with parts of Bristol and Somerset down south in line with parts of Manchester, Bradford and Leeds looking good further north right now.

Cheers

gottolovethisweather

Absolutely no chance here of any sferics. Expecting on and off drizzle for the day ahead (Bradford and storms go together like pasta and custard lol). The NMM shows that there is very little CAPE around West Yorkshire today, although East Yorkshire looks better. Best chances today are across the Midlands (especially East Midlands) and then East Anglia and the SE look good for later on this afternoon.

Edited July 29, 2012 by Supacell

[Coast]

Along with the Netweather forecast, UKASF have one out too:

Storm Forecast Moderate

Forecaster: Dan

Last Updated: 2012-07-28 20:30:00

Valid: 2012-07-29 00:00:00 - 2012-07-29 23:59:00

Synopsis:

Large upper trough with cold mid-levels (~-24C at 500mb) with the jet on the southern flank over northern France. A day of widespread convective showers is expected across much of the British Isles.

Discussion:

Widespread showers and thunderstorms are expected as ~700J/kg CAPE develops in response to rising LSTs. Rather weak shear will mean convection will be poorly organised, with a series of \'pulse-type\' storms expected. There is sufficient dry and cold air aloft for hail in many of the stronger cores, with a local event >2.5cm in diameter possible.

While PWAT are <20mm generally, slow storm motion and \'shower trains\' may give rise to flash flooding locally.

Showers will generally decrease in coverage during the evening hours as daytime heating subsides, but are likely to continue overnight in places due to the proximity to the upper trough.

... SW, CS & SE ENGLAND ...

Most models simulate a W-E line of convective showers/storms through the morning and first half of the afternoon, before weakening and shifting eastwards by late afternoon. With such CAPE values and close proximity to the jet, providing some speed and weak directional shear, cells are likely to be better organised here with more frequent sferic activity. Such (albeit weak) shear will also increase the chances of rotation, resulting in a funnel or weak tornado event potentially.

... EAST ANGLIA ...

During the afternoon, there are signs that convection may become better organised into a NE-SW oriented line, with the most mature phase (in terms of sferics) likely to be over central and eastern parts of Suffolk and Essex, and subsequently clearing over the North Sea later. Slight speed shear here also increases the chance of a funnel or weak tornado.

Nice bit of surface CAPE around this afternoon and that spout type feature down around the Olympic sailing venue:

Chances all over Southern England today:

[Supacell]

Did nobody in NE Essex see the lightening about 11.30pm last night?

Was it the storms over the North Sea giving a distant display?

[Biggin]

Along with the Netweather forecast, UKASF have one out too:

Thanks as usual Coast

[legritter]

dry here at the moment but something brewing to my west . dont think there will be a repeat of 5 30 this morning absolute peach thunder and intense rain ,but very short lived ,an interesting week possible

[Keraunic]

Sunny and warm here with some cloud and very still. Supposed to be T& L this aft so fingers crossed and good luck everyone.

[bobbydog]

radar showing lots of activity popping up along southern counties.some impressive looking clouds around and its just started raining here as i type!! - and its bright sunshine apart from the dirty great cloud right above me!

[IanR]

Was in Manchester today, Manchester Airport to be specific. Had two fantastic Thunderstorms to add to my yearly total, as I got caught out walking in them and got saturated... felt well nice.... How about that!!

DAMMIT ! I was so close to this, I saw the CB in the distance sliding from west to east across the sky, but assumed it was just a heavy shower, if only I has taken a 15 mile drive south, You are SO lucky with storms , they seem to follow you and avoid me,

Here you are coming to my storm starved region were I have has nothing, then come and get a storm here, after the many you have had in London, its not fair