UK Convective General Discussion & Forecasts - May Into June 2012

[Coast]

A brand new thread for storm fans, taking us out of May and into June 2012!

[dallas]

I beleive there are some chances of some storms later, not sure if they will be as sharp as yesterday, mainly S/E again.

More widespread tomorrow

[snow raven]

Yesterday was a great big fat disapointment in my neck of the woods - lets hope any storms that develop are more widespread today!

[dallas]

My area got it, but was at work so missed it

[Coast]

Here we go then, a round up of what other sites and charts are pointing to:

ESTOFEX have bits of the UK under watch:

Storm Forecast

Valid: Tue 29 May 2012 06:00 to Wed 30 May 2012 06:00 UTC

Issued: Tue 29 May 2012 05:46

Forecaster: SCHLENCZEK

A level 1 was issued for W France and N Italy mainly for large hail and local excessive precipitation.

A level 1 was issued for N Algeria and N Tunisia mainly for large hail and severe wind gusts.

SYNOPSIS

High geopotential heights are found over most portions of Europe except for Scandinavia and NW Russia. A weak upper low over the Balkans may lead to unsettled conditions over SE Europe. Warm and unstable air is found in most places of Europe, even near the axis of the upper ridge which extends from France towards Greenland. On Monday, most convection will occur in a low shear environment.

DISCUSSION

...W/ SW France and N Italy...

Recent models show that MLCAPE in order of 1000 - 1500 J/kg is likely created during the day which allows storms in a low shear environment to become marginally severe. The prominent threat should be large hail and local excessive precipitation.

UKASF:

Forecaster: Dan

Last Updated: 2012-05-28 21:24:00

Valid: 2012-05-29 00:00:00 - 2012-05-29 23:59:00

Areas Affected:

SLGT: Midlands, Home Counties, London, SE + CS Eng and W/N Ireland

Synopsis:

Upper trough continues to swing northwards across the British Isles with some mid-level instability still present. Cooler air attempts to migrate southwards behind a weakening cold front.

Discussion:

Once again rather slack conditions will be present at the surface, allowing seabreezes to develop and consequently some convergence. A cooler undercut is expected as northeasterly winds strengthen, and thus lowering daytime maxima potential compared to recent days.

As a result, a few showers and isolated thunderstorms may develop, but will rely heavily on convergence, orographical lifting or frontal forcing. Current thinking is some surface convergence will be present near a very weak frontal boundary over the Home Counties towards the East Midlands, and therefore it is this area that currently exhibits the greatest chance of a few showers developing.

Some low-level convergence over Connaught and west Ulster will also allow a few showers and/or thunderstorms to form there also.

Shear once again is rather weak or non-existent, and so such showers will be poorly organised and may not be particularly long-lived. There are suggestions of some slight directional shear in the lower layers, which may assist in separating updraft/downdrafts to sustain such a cell for a short period of time, but the lack of any strong synoptic-scale forcing suggests that showers/storms will be shorter-lived than those of Monday.

PWAT >24mm locally could mean that slow-moving showers have the potential to produce some significant quantities of rainfall over a small area and thus increasing the potential for localised flooding; else severe weather is unlikely.

Nothing so far from SkyWarn or TORRO, so here are a few pictures to colour-in during your morning break!!!!

The lightning ensemble probability looks to be more to the West of the country:

No real CAPE to talk of, so perhaps we better look for some other trigger:

Convergence over Hants and IOW mid-afternoon, will this be the smoke before fire?

SB CAPE and the spout index looking much better along the South Coast corridor, maybe I'm in with a chance this time? (http://lightningwiza...WeatherMaps.pdf)

GFS confirming their belief that the Isle of Wight might be the place to be, I hope it can travel East up the coast a bit more too!!!!

[Coast]

Tomorrow looking better for East Anglia:

[StLuke]

Unbelivable contrast yesterday here in Southend, left work in Leigh about 5.30 with thunder and lightning all around but completely bone dry, travelling home towards central Southend and the heavens opened the dividing line was so clear a foot step either side made the difference between nothing and almost flood conditions! What was clear from driving further was that it had be like this for a while with rivers in the road and water coming up through the manhole covers and the smell of sewage in the air where the drain systems were overloaded! Looking at the radar when i got in showed the eastern half of Southend under a white blob compared to nothing over the western side, just shows how much of a fine line it can be.

[BrickFielder]

Good forecast my the MetOffice yesterday they pretty much got it spot on.

Today convergence zones and moisture convergence in the lowest levels are likely to be the trigger for any storms today.

Key area is likely to be south of London from the forecast charts.

Forecast SkewT's show temperatures and low level moisture is key.

Possible spoilers are residual cloud from decaying frontal system sweeping down the north sea and the low pressure system out to the south west not behaving as expected. Main risk will be isolated heavy downpours mainly in the south. Other areas to possibly watch would be just north of exeter, lincolnshire and perhaps through oxfordshire.

[daggerdanny]

Yesterday was a great big fat disapointment in my neck of the woods - lets hope any storms that develop are more widespread today!

Same here, today I dont want anything as playing golf this afternoon but tomorrow I am off to Cambridge so hopefully see some action on the way back.

[Coast]

Dew points already creeping up and locally at 14.5°C;

they look set to remain high in the South:

[The watcher]

plenty of cu bubbling up here, can watch them grow too. Slight risk for me with a low level convergence area nearby.

[Coast]

plenty of cu bubbling up here, can watch them grow too. Slight risk for me with a low level convergence area nearby.

Peaks at around midday:

[Robbie Garrett]

PROB30 TEMPO 2913/2922 4000 +SHRA TS BKN040CB for most Airports in the South East....

Probability 30% : Temporary

from 29 at 13 UTC to 29 at 22 UTC Visibility 4000 m Broken clouds at a height of 4000 ft , Cumulonimbus. heavy rain showers and thunderstorm

[Neilsouth]

But its cloudy

[dallas]

Met office warning

http://www.metoffice.gov.uk/public/weather/warnings/

[conor123]

Cloud clearing eastwards now with sunny spells spreading in so hopefully some convection can get going!

[Mapantz]

The sun is completely blotted out by cumulus now. 14.5C dewpoint, it does look as though something could trigger here, but i won't hold my breath.

Check my station below and follow the webcam link in the nav bar for a look.

[Tim B]

Quite a lot of convection up here today, wouldn't be surprised to see a storm today.

[Lynxus]

Just warm, cloudy and muggy here.

Not expecting anything today, tomorrow or ever

[Neilsouth]

Hopefully we get rid of this crap cloud, however bbc forecast said storms could rumble into the late evening?

[Robbie Garrett]

Met office warning

http://www.metoffice...ather/warnings/

Yeah just seen that, as there's a lot of Cu going up now. A lot more then yesterday. Probably a better chance for Central London Areas than yesterday.

[dallas]

Yeah just seen that, as there's a lot of Cu going up now. A lot more then yesterday. Probably a better chance for Central London Areas than yesterday.

Yes the area does seem more west

[Marcus_surfer]

Unbroken sunshine here looks like we are in the wrong place for storms again this summer.

[snow raven]

Yeah just seen that, as there's a lot of Cu going up now. A lot more then yesterday. Probably a better chance for Central London Areas than yesterday.

Yes the area does seem more west

Let's hope so

[Costa Del Fal]

Cloud clearing now however storm chance is minimal. Same for tomorrow.