Convective Discussion

[Costa Del Fal]

BBC Maps show some intense showers this evening and overnight here. Potential to be thundery after dark too.

and to last overnight too

Think the BBC is overdoing this just a little bit

It is actually true that they may last overnight. The showers are not dependent on daytime surface heating is what im told.

[Gordon]

Does anyone know how strong these storms will actually be ?

What I am trying to ask is will these storms be considered strong/severe in uk terms or just typical uk type

Hope somebody understands the question I am trying to ask

[Coast]

Storm Forecast

Valid: Sun 13 Jun 2010 06:00 to Mon 14 Jun 2010 06:00 UTC

Issued: Sun 13 Jun 2010 05:51

Forecaster: SCHLENCZEK

SYNOPSIS

A low pressure system over S Finland associated with a thermal wave over W Russia will move northeastward during the period. Over western / central Europe, a stationary upper trough remains, leading to a quasi-stationary frontal boundary which stretches from the N Adriatic via NE Ukraine towards NW Russia. Hot and moist subtropical air is located ahead of the front with CAPE in order of 1500 - 2000 J/kg forecast by GFS. A region of strong deep layer shear is located near the frontal boundary with still locally 15 - 20 m/s on the warm side. Further west / southwest, a moderately warm airmass overspreads parts of SW / W Europe with only marginal instability created by diurnal heating. An upper shortwave trough will cross the British Isles from NW to SE during the afternoon / evening hours.

DISCUSSION

...British Isles...

A few hundred J/kg CAPE are forecast in the wake of the approaching upper trough. Low level winds are very weak and deep layer shear should be less than 10 m/s in most places but a low cloud base and locally augmented 0-3 km CAPE may allow a brief tornado.

Storm Forecast Issued: 2010-06-12 16:23:00

Valid: 2010-06-13 00:00:00 - 2010-06-13 23:59:00

Regions Affected

Wales, Midlands, SW England, parts of E Anglia & Northern Ireland (all of England, Wales and Northern Ireland are included in the WATCH)

Synopsis

A shallow area of Low pressure moves southeastwards across the United Kingdom on Sunday, dominating the weather.

Behind an increasingly weak eastward-moving cold front, scattered showers and isolated thunderstorms are forecast to develop in the unstable airmass during the afternoon and evening, moving in a predominantly southeasterly direction.

Showers will be fairly quick-moving, but may be accompanied by hail and gusty winds. The showers (and storms) will persist throughout the night across England and Wales with still a risk of electrical activity

.

Watch that middle band of the country late afternoon!!!

[Gordon]

If this was for my benefit then Thanks even if it weren't Thanks anyway

[r6 steve]

well not exactly sure of my chances today but later on tonight and maybe hopefully tomorrow we could see something down here?

[Craigers]

still good news for yorkshire but southyorkshire really

NMM clearly shows where the showers will be and dew points looking good! could get interesting over yorkshire! also midlands aswel!

this also looks interesting!

[Gordon]

thanks for those maps

surprised to see the worse instability and rainfall over more e/se parts at 18z that's if i am reading your maps correctly

thought that would have been slight further west

[Craigers]

thanks for those maps

surprised to see the worse instability and rainfall over more e/se parts at 18z that's if i am reading your maps correctly

thought that would have been slight further west

its been forecasting this for past day or so!, cape is being used up where the heavy showers are on the map so for my take on these maps is southyorkshire, lincolnshire and north midlands and then east midlands later on. looking good

Edited June 13, 2010 by Craigers

[Gordon]

Well if your reading of the maps is correct and I hope it is

I will miss the very worst of the showers

It won't be dry where I am but hopefully not too heavy as I have a guttering issue and a lazy council

[BrickFielder]

Looking at the surface wind maps we might have a small chance of a convergence zone type tornado.Many for more northern parts of England , but perhaps along east coasts where sea breezes develop.

Forecast SkewT's whoul moderate instability with fairly weak winds in the lower levels. We also have moisture all the way up which will tend to make things somewhat messy with less tendency towards severe storms.

Keep you eyes on the radar out west.

[Gordon]

Severe or organized storms are rather unlikely (although there is some DL shear and CAPE overlap for a time). Approach of low and associated upper cold pool, characterized by rather steep 850-500mb lapse rates, along with sufficient surface heating and dewpoints into low teens, will help to develop showers and weak thunderstorms across many parts of England and Wales. Main threat will be gusty winds and small-sized hail given cold air aloft.

Looking at the models yesterday evening, there were some suggestions that a risk of isolated storms would extend further south toward southern UK, but overall risk looked pretty low. Surprised at the change 12 hours later!

Thanks for the info

weak storms is something I can just about cope with

Edit : BBC Weather Site has just updated it's maps and now shows rain not as heavy but still some some heavy bursts but slightly more widespread and with worst of the rain between 7pm and 1am

Edited June 13, 2010 by Gordon

[Guest]

its been forecasting this for past day or so!, cape is being used up where the heavy showers are on the map so for my take on these maps is southyorkshire, lincolnshire and north midlands and then east midlands later on. looking good

This is where my hope clings on to! All other forecasts have mentioned Midlands southwards, but neglected S.Yorks! Not Netweather! Fingers crossed Craigers

[user700]

Thanks for all the weather charts

[dogs32]

BBc to me suggesting more of a Midlands and Southern Midlands or even further South for any Torrential downpours....

But he was vague with his hands on t he charts for the areas to see this happen

Looks like something slowly building out West on Radar(West Wales)

Edited June 13, 2010 by dogs32

[Gordon]

I think It'll be a case of some places getting a soaking and some getting very little depending on your location and the BBC are also forecasting these showers to ease later which is something they were not doing this morning

[jello]

Having rumbles of thunder here recently.

Warning out

Torrential rain, Hail Stones & Thunderstorms becoming widespread this afternoon. Localised flooding likely.

[dogs32]

Rain over Wales is associated with the cold front/occlusion. The risk for heavy showers and perhaps weak thunderstorms from the Midlands southward will be greatest from late afternoon onwards and throughout the night, as Low and associated upper cold pool situates over central and southern England, so sufficiently unstable airmass present after sunset.

yes BBC were suggesting the Torrentail downpours after dark but some possible breaking out this afternoon

Love night lightning...can we be lucky tonight...

edit..my Emoticons are not working!!!

Edited June 13, 2010 by dogs32

[r6 steve]

well fingers crossed for us down here on the south coast the last time we had thunder was the end of march not a long time waiting i know but for me its too long!! lol

[Gordon]

Well I'm in a minority here I suspect But I don't want a single flash of lightning or rumble of thunder in my area as I can't stand them

good luck to those who like them though

[r6 steve]

so we could never call you flash gordon then? lol

Edited June 13, 2010 by r6 steve

[Dorset_Weather]

Met office warnings now out for Wales.

http://www.metoffice.gov.uk/weather/uk/uk_forecast_warnings.html

Edited June 13, 2010 by hazard

[r6 steve]

hi hazard

what do you think our chances are for some activity down here?

[dogs32]

Met office warnings now out for Wales.

http://www.metoffice.gov.uk/weather/uk/uk_forecast_warnings.html

yes they are intensifying also as they spread East

[Neilsouth]

Just seen alot of altocumulus here but are we expecting anything?

[r6 steve]

i think later tonight us in the south and south east sector can expect something hopefully!!