Convective/Storm Discussion early to mid June (merged)

[richep]

We've got a very dark black cloud moving over here right now,no rain but I reckon as this moves northwards it could build into a heavy shower or storm.I'm gonna get some shots of it once it's passed and post them in a bit,but it does look and feel very thundery here

[chapmanslade]

I'm surprised the cap hasn't been broken with temps that high. Maybe the front you mention will help force those clouds up through the cap. I'm hoping they then move northwards towards the Midlands.

I'm fairly confident the temperature is accurate as I have pretty much matched the Yeovilton figures so far today (Yeovilton's latest reading was 23.2C at 14.00)

[Snowkissed]

I've just come back from underneath the cells over Hants/Dorset. Very poor visibility, and very capped from viewing from the south. Underneath, light rain and drizzle, odd large raindrop, some very wet patches on A31 near Burley, but nothing of note. No structure visible due to haze underneath.

I have just got back from the Wimborne festival and I have to say that I have not seen the weather look so stormy for a long time. The word is 'muggy' and it is very very close. Clearning skies over Poole and Bournemouth though.

Edited June 9, 2007 by Snowkissed

[richep]

Heavy shower in dorset to keep an eye on,are showers likely to move north throughout today,as this one appears to be moving west

[Andy Bown]

Definite cap here still, but very vigorous convection below that. Temp flattening out at 26.1C with a dew point of 15.2C - awaiting the sea breeze front which normally arrives here around 16.00

Am glad you've got 26c too! We have had a lot of sunshine until 15.00 to help it lift that high.

Can you see the very dark, large cloud that's edging in towards Westbury from the SSW? It's pretty impressive given that it's front edge is just over my house next to an equally large clear area.

[Supacell]

Another heavier shower has popped up around West Sussex. I am also thinking that during the evening, as cloud tops cool, there could be further development.

[chapmanslade]

Definite cap here still, but very vigorous convection below that. Temp flattening out at 26.1C with a dew point of 15.2C - awaiting the sea breeze front which normally arrives here around 16.00

It was 10 minutes early ! Wind now a SSW from a NNE. Very congested sky to the south so not really very easy to interpret.

[Nick F]

Another heavier shower has popped up around West Sussex. I am also thinking that during the evening, as cloud tops cool, there could be further development.

I think it's unlikely that the showers appearing now over central Sern England will continue after dark - as they are mainly being driven by sea breeze front wind convergence (which is a day-time phenomenum - winds blow off land at night) and also by surface heating. Showers should die out in the early hours when these drivers disappear. Convection that springs to life in the early hours as mid-upper temps cool nocturnally (steepening lapse rates) are normally the reserve of elevated moist plumes which push North out of France, that isn't the case today. Rather we have a rather warm moist boundary layer which through wind convergence and sfc heating is being lifted upwards into the reminants of an upper cold pool that moved East the other day over Sern England.

[richep]

Heres a couple of shots taken about 20 minutes ago

[Nick F]

Recent wind chart shows roughly where sea breeze front/convergence line is:

Some moderate rainfall rates from two small cells just North of Portsmouth atm, upslope lift of the South Downs Escarpment perhaps aiding those particular cells too (presuming they're not anaprop).

Had a fair bit of Tcu building around here too this afternoon, it's begining to merge with some dark bases around but as yet nothing coming out.

[The Eagle]

Storms developing in the Bay of Biscay at the moment may have an impact on Western areas later tomorrow (the Southwest of England) or Monday/Tuesday. It will be interesting to watch how that developes.

[Andy Bown]

That's about right Nick, as Chapmanslade said - the wind has changed direction recently.

Very impressive clouds there Rich, looks similar to my W and SW now.

[Costa Del Fal]

Heres a couple of shots taken about 20 minutes ago

On the last picture you can see it rain!

Edited June 9, 2007 by Nick F
Too much scrolling with pictures included in quote

[Nick F]

Dark cloud base area just West of here seems to have developed a rain shaft, cell motions of showers that develop over Sern England would appear to be SW-wards, with steering winds NE'ly at 700-500mb.

[tcc]

Yeah definitely heading southwestwards here, a dark cloud just went over here but no rain, getting brighter now.

[Karen Ann]

[quote name='Snowkissed' date='9 Jun 2007, 03:35 PM' post='995557'

I have just got back from the Wimborne festival and I have to say that I have not seen the weather look so stormy for a long time. The word is 'muggy' and it is very very close. Clearning skies over Poole and Bournemouth though.

[*Stormforce~beka*]

Some moderate rainfall rates from two small cells just North of Portsmouth atm, upslope lift of the South Downs Escarpment perhaps aiding those particular cells too (presuming they're not anaprop).

Nah think they are real mate. Just come back from Tesco's by the A34 and saw a VERY impressive cell to the NE. Looks like a real good cauliflower. Extremely dark bases. That will be dropping soon I think.

[Noctilucid]

Ive just been told by my dad that there was distant booming thunder to our south about and hour ago, i noticed some very dark bases but i thoughtit was aircraft, i couldnt see the tops of thses cluds but my dad has confirmed that there was thunder coming from it a few miles to our south.

Its all cleared southwards now anyway.

Joe

[johnholmes]

hi

this may help some of you

coming up in a tic,

first a surface chart with a convergence zone possibly set off by sea breezes along the south coast.

secondly the releavant upper air ascent, and as I've typed on it, it is just possible for a Cumulonimbus to form

hope some of you thunder fans in that area are lucky.

It is possible as my sea breeze article suggested.

and from Net Wx Extra radar at 1710

http://www.netweather.tv/secure/cgi-bin/pr...79f52f38c74d1ea

Edited June 9, 2007 by johnholmes

[Nick F]

1500hrs Satellite shows nicely the Tcu along the convergence line over Sern counties of England:

[Supacell]

Have noticed that there is one lightning strike on the netweather lightning detector near the South Coast.

IOW lightning detector has several strikes now showing up over Lincolnshire

[kaz]

Hi just got back from hicking over exmoor... Towers building all day as far as the eye could see and as i was up high that was very far.... Very dark clouds all around me very hot and humid sun went in at about 2.30 but still remained very hot. the clouds were moving NW ... seemed to be getting alot of lift.. hard to see in the end as a haze developed.. remained dry but did look very stormy over minehead way..

kaz x

[richep]

Starting to rain here now from a dark sky

[MP-R]

Very warm and humid here. Can see lagre towers going up everywhere, surprisingly though, nothing to the southwest?? Must be the sun and the haze. A lot of altocumulus here, maybe a good sign of things to come.

[rob-lancs]

Weathers been great here. Very misty in the sound though. Been to the South Hams today and in one of the bays, the water appeared to be steaming.

I was parked up at the other side and actually felt the difference on the car park, the nearest side to the cliff was warm and muggy, the other side was really cold and damp.

Edited June 9, 2007 by rob-lancs