Uk Convective General Discussion & Forecasts, 12th to 14th August 2012

[Hathers]

How is Wednesday looking guys? I heard there were potential for some thunderstorms to break out.

[Costa Del Fal]

Evidence for this?......or rather a glass half empty post that requires activation of the 'whiners' thread?

:lol: Just the UK's sods law and lets face it, its happened many a time before. However 28th June will always give me hope for the future. Dont worry AJ, Im certainly not writing this weekend off! You know Im better than that!

[A.J]

Just the UK's sods law and lets face it, its happened many a time before. However 28th June will always give me hope for the future. Dont worry AJ, Im certainly not writing this weekend off! You know Im better than that!

I was pulling your leg.......TBH as already posted, if those charts verified then it would be hot & that's just about it with not so much a cap in place, rather a lead & concrete composite barrier in the sky, surrounded by mine fields with large signs reading 'Trespassing rising air will be destroyed'...lol

[Carl46Wrexham]

How is Wednesday looking guys? I heard there were potential for some thunderstorms to break out.

I expect Wednesday to be a very wet and windy Autumnal style day, Not buying into this storm potential one bit.

Edited August 13, 2012 by Carl46Wrexham

[Costa Del Fal]

I was pulling your leg.......TBH as already posted, if those charts verified then it would be hot & that's just about it with not so much a cap in place, rather a lead & concrete composite barrier in the sky, surrounded by mine fields with large signs reading 'Trespassing rising air will be destroyed'...lol

Indeed, CIN is pure evil but indestructible sadly. Maybe the Top Gear team could somehow blow CIN up.

Ahh well and back to the models, Wednesday is still on, recent GFS runs perhaps upgrading CAPE a bit, esp for the Midlands,b earing in mind this is just one of the few important ingredients needed. Severe potential still there. How id love 28th June again.

Edited August 13, 2012 by Blizzards

[Supacell]

The current output for the weekend is showing high temperatures and lot of sunshine for the SE half of the country, but little in the way of storms as the cap will be too strong (regardless of CAPE) in this area. Further north and west would have a better chance of storms with less impressive CAPE but less of a ridge sitting on top of the atmosphere so storm could fire. Of course, subject to change as its several days away yet.

EDIT: I like AJ's description better

Onto Wednesday... there looks to be much less SBCAPE than on the 28th June but similar shear and helicity so not sure it would match that event, but still likely to bring a severe threat of torrential rain, gusty winds and tornadoes. I would expect sferic activity to be a bit sparse though, as CAPE does not look conducive to a massive lightning event (experts correct me if i am wrong). I think we would be hard pressed to match the 28th June 2012.

Edited August 13, 2012 by Supacell

[Chris W]

That line in Wales to the Irish Sea has produced at least one sferic on the ATD. The Met Office also have a thunder symbol over Chester for 10pm.

Edited August 13, 2012 by Chris W

[syed2878]

guys a question. If wednessday's event looking bad y haven't the met office got a warning out? I been looking on their mobile site not even an earlly warning.

[Chris W]

There is a yellow warning for western parts of the UK:

Issued at: 1151 on Mon 13 Aug 2012

Valid from: 0600 on Wed 15 Aug 2012

Valid to: 2359 on Wed 15 Aug 2012

Heavy rain, accompanied by strong winds, is expected to spread north during Wednesday morning and afternoon, to affect parts of western England, much of Wales and Northern Ireland. The heaviest rain is likely to clear from the south by evening, but the strong winds may peak a little later.

The public should be aware of the possibility of surface water flooding and the likelihood of difficult conditions for travel and some summer holiday pursuits.

[Chris.R]

Can hear some really close sferics on the radio but no thunder yet. My friend says that there's lightning over hillbre island coming this way. Yes!

[Eskimo]

Can hear some really close sferics on the radio but no thunder yet. My friend says that there's lightning over hillbre island coming this way. Yes!

When you say sferics on the radio...how do you do that so you can them up?

Edited August 13, 2012 by Perfect Storm

[Supacell]

Can hear some really close sferics on the radio but no thunder yet. My friend says that there's lightning over hillbre island coming this way. Yes!

If it were night you would probably be able to see flashes out to sea as they are not too far out to your west

Edited August 13, 2012 by Supacell

[Chris.R]

Just tune your radio to the lowest frequency on AM so that all you can hear is static. Every time there is a lightning strike you willl hear a crackle. The louder and sharper the crackle then the closer the strike usualllly.

Can still hear some really big sferics here and it's getting very very humid with a strengtherning wind.

[Chris.R]

Wow that one was massive! I wish it was night, I think there wulld be quite a lightshow.

[Supacell]

I wonder if that line over Wales is going to affect this area at any point tonight? Wish i was around Barrow in Furness as that looks to be the area to get hit by the storm currently in the Irish sea and spreading north.

[Nick F]

Lots of sferics over Liverpool Bay on Atd, also a lone one over E Sussex, getting a downpout here atm as it happens.

How is Wednesday looking guys? I heard there were potential for some thunderstorms to break out.

Still looking very interesting from a severe storm potential, warm and very moist air advecting NW in warm sector ahead of cold front moving in from the SW - theta-w values of 16C.

Strong DL and LL shear in warm sector with significant tornado parameter shown on Lightning wizard:

My only concern is cloud cover limiting instabilty.

[Stuart]

SKYWARN UK SEVERE WEATHER WATCH #048

ISSUED: 1500UTC MONDAY 13TH AUGUST 2012

SKYWARN UK HAS ISSUED A SEVERE WEATHER WATCH FOR THE FOLLOWING REGIONS:

ALL AREAS UK

IN EFFECT FROM 0000UTC WEDNESDAY 15TH UNTIL 1500UTC THURSDAY 16TH AUGUST 2012

BISCAY LOW DEEPENS TO ~980MB INTO THE SOUTHWEST, DRIVING STRONG INSTABILITY AHEAD OF AN ACTIVE COLD FRONT WITH GALES FOLOWING

THERE IS A POSSIBILITY OF SEVERE WEATHER AFFECTING THE INDICATED REGIONS IN THE TIME PERIOD SPECIFIED. THREATS WITHIN THIS WATCH INCLUDE, BUT ARE NOT LIMITED TO:

HEAVY RAIN...FLOODING...GALES...STRONGER GUSTS...FUNNELS/TORNADOES

DISCUSSION:

THERE IS ADEQUATE MODEL AND AGENCY CONFIDENCE IN A SEVERE WEATHER RISK THROUGH WEDNESDAY INTO THURSDAY TO WARRANT EARLY ISSUANCE OF A WATCH. A LOW DEVELOPS UNDER A STRONG JET CORE IN THE BISCAY AREA AND SOUTHWEST APPROACHES, DEEPENING TO PERHAPS BELOW 980MB WHICH IS UNUSUAL FOR SUMMER. A VERY WARM AND MOIST AIRMASS WILL BE ENCOURAGED NORTH FROM FRANCE AHEAD OF THIS, PROVIDING POTENTIAL FOR EXTREMELY HEAVY RAIN IN RELATIVELY SHORT PERIODS AS THE FRONT PUSHES ACROSS THE UK. ACCUMULATIONS OF UPTO 40MM LOOK LIKELY IN MOST AREAS, WITH SOUTH AND SOUTHEAST FACING SLOPES POSSIBLY HIGHER GIVEN STRONG WINDS ALONG THE FRONT. SOME CONVECTIVE INITIATION IS POSSIBLE AHEAD OF AND WITHIN THE FRONTAL ZONE, PROVIDING FOR POSSIBLE PRECIPITATION AND WIND ENHANCEMENT AS DIRECTIONAL SHEAR IS FAVOURABLE FOR ORGANISATION AND POSSIBLY FOR FUNNELS OR TORNADOES. STRONG THUNDERSTORMS IN FRANCE MAY ALSO CROSS THE CHANNEL IN THE EARLY HOURS OF WEDNESDAY AFFECTING MOST AREAS OF THE SOUTH COAST. BEHIND THE FRONT CLOSER TO THE LOW CENTRE, GALES ARE LIKELY WITH GUSTS PERHAPS EXCEEDING 60MPH, MAINLY AROUND AREAS BORDERING THE CELTIC AND IRISH SEAS BUT ALSO HIGH GROUND OF WESTERN MAINLAND UK AND EXPOSED AREAS OF NORTHERN IRELAND. THIS WATCH WILL BE UPDATED AND POSSIBLY UPGRADED.

SPOTTER ACTIVATION IS REQUESTED AND SPOTTERS ARE REQUESTED TO REPORT ALL FACTORS EXCEEDING ACTIVATION CRITERIA.

http://skywarn.org.uk/current.html

[I Cumbria Marra I]

TStorm looking like it could hit me, geddin

[Chris.R]

Storm in the bay has dide. Just great. Anything elce look like developing or should I just give up again!

[Supacell]

Storm now kicking off in SE London and some showers breaking out over Cambridgeshire. Could be getting ready to be sucked into Lincolnshire later on this evening

[NUT]

Usually it this time of day things are starting to drop off but seems it just getting started now

[East_England_Stormchaser91]

Usually it this time of day things are starting to drop off but seems it just getting started now

Normally the case with a typical boring westerly! I find southerlies like this though straight up from near Spain provide greater amounts of potential at any time of the day, Been seeing Spanish plume like altocumulus and altostratus for a couple of days now advecting N. Looking like its gonna get a lot worse this coming week too. At last! some exciting weather is likely to be on the cards

[SP1986]

I saw the cell moving over Hilbre Island way, but saw no lightning or heard any thunder from it, which is fairly typical, as we will be lucky to see any of that here.

[tara303]

OOh lights flickered here, and internet been off a few mins???

[Chris.R]

Yes I just heard thunder. Very distant over the wirrel but it was thunder. The sky's gone all funny as well.