22nd into 23rd Aug 2011 - Storm/convective Forecast Discussion And Reports

[carinthian]

Hi, just spoke to my daughter who lives on West Worthing Seafront, she can see lightning out to sea in the direction of Dieppe, but thinks its some way out.

C

[Dean E]

I love the way this ppn now has the name 'Frenchie' !

I have to admit thought, 'Frenchie' is some size! More currently developing behind her, This could give some serious rainfall totals once shes hits our shores!

[coldfingers]

It is moving into the channel but the main centre of lightning activity is staying near the french coast with new cells erupting further south and east...I think Estofex have got this one right so far, but I'm quietly confident that once the MCS makes landfall it will reinvigorate as nocturnal cooling takes effect completing the transformation into elevated thunderstorms (my understanding is that the MCS is surface based, so once it hits cold water, convection is weakened as the surface heat source is lost, however warm moist air is still being advected NE into the MCS, and as cloud tops continue to cool, a sharp temperature gradient is generated between the warm mid-level air and cold upper air thus regenerating mid-level convection.....I think!)

Sea Temp here on the coast is 18.6C a couple of degrees warmer than the air temp of 16.6C. Would that make a difference? I am clutching at straws here. LOL.

Edited August 22, 2011 by coldfingers

[NO LONGER POSTING]

frenchie could soon become Monster frenchie..Bring home the cheese baby!!

[Harry]

I'd also like to point out the humidity has jumped quite considerably in the past 60-90 mins - low level clouds including some Cu are streaming in from the ESE while the main bank of Ac continues to stream in from the south...most probably the anvils of Frenchie.

Don't expect uniform development/activity...MCS' are seldom uniform and will collectively pulsate like a jellyfish, going through phases of weakening and intensification.

UKASF anticipate the lightning activity to re-invigorate as it moves over the channel but appear pessimistic once it reaches land.

[NO LONGER POSTING]

I love the way this ppn now has the name 'Frenchie' !

I have to admit thought, 'Frenchie' is some size! More currently developing behind her, This could give some serious rainfall totals once shes hits our shores!

Want to take the glory for naming her frenchie XD

[Chris K]

Just thought I would point something out..In the last 30 mins the strand of rain over the South west of the UK has began to pick up slighty noticeable on met weather..

Seems to be fragmenting on the rain radar, hence why i've gotten irritated at the fact my area is getting bugger all, except a bit of rain once again by the looks of things...thanks mother nature!

Think I'm going to call it a night soon and do something else.

[Jane Louise]

Hi, just spoke to my daughter who lives on West Worthing Seafront, she can see lightning out to sea in the direction of Dieppe, but thinks its some way out.

C

Hi carinthian thanks for letting us know.

[A.J]

er theres been no ESTOFEX forecast !

That was supposed to read UKASF! doh!

[Neilsouth]

Decaying rapidly

http://www.meteox.nl/gmap.aspx?soort=loop3uur&zoom=6&lat=52.908902047770255&lon=-1.845703125

While the storm across north east france explodes and is possibly dangerous!

[camiscool]

NOOOO DONT DECAY

[West Sussex Kate]

Its all kicking off soon then!

[Robbie Garrett]

I'd also like to point out the humidity has jumped quite considerably in the past 60-90 mins - low level clouds including some Cu are streaming in from the ESE while the main bank of Ac continues to stream in from the south...most probably the anvils of Frenchie.

Don't expect uniform development/activity...MCS' are seldom uniform and will collectively pulsate like a jellyfish, going through phases of weakening and intensification.

UKASF anticipate the lightning activity to re-invigorate as it moves over the channel but appear pessimistic once it reaches land.

I've noticed this, you can see the Cu more clearly aswell, I've turned my lights off so I can get a better view tonight. Got my HD 1080p camera charging which has a direct view of South London, which apparently has a severe flood warning on with the LFB. Only problem is the camera can be very grainy at night.

Bear in mind that weather forecasts as they are now (from Meto and the BBC) have thunderstorms also coming in from that unstable (though currently dry) air over Belgium and Holland that we saw on a map a page or so back. Wouldnt also be surprised to see that 'secondary' (we'll call it secondary) orange and white blob behind the main front to expand and perhaps move slightly further east as it crosses the channel. No real scientific reason - just a combination of instinct and bbc forecasts....news worthy storm, this is!

It's not on BBC forecasts/metoffice at all, just light rain according to what I am looking at.

This is a beast though, I've not seen anything like this in a long time - at least 10 years.

COME ON FRENCHIE!!

[Harry]

Perhaps the more experienced will either agree or disagree, but is that a bowing MCS? It appears to me the front edge is moving out due north ahead of the rest of it - coupled with that it has shown signs of some exceptionally intense rainfall on the leading edge...if it indeed is a bowing MCS (verging into the severe category of storms I'd suggest) then it is likely to be packing some VERY strong winds on the leading edge, not ideal for any boats/ships which may be in the channel....that said, the 'bowing' feature could simply be associated with the winds arching around the LP centre...worth keeping an eye on though IMO

[Dean E]

Keeping a close eye on the frontal boundary currently stretching from Brest Peninsular to SW London, this area is slowly been increasing in intensity over the past few hours...

Meanwhile, frenchie is still producing some distant flashes and continues to strengh but a slight decrease has been noted in the last radar run

[flysurfer]

NOOOOOOOOOOO jesus there it pops..

[Hathers]

It will regain intensity once it hits land folks so don't worry.

[cmimrie]

fergieweather Ian Fergusson

ATDNet continues to confirm thundery elements of 1st MCS now decaying quickly. Latest MetO model shows less rain Bristol AM. Wilts v wet tho

Edited August 22, 2011 by cmimrie

[Harry]

Yeah don't worry for heaven's sake...there's still a lot of activity exploding over France and still a lot of moisture advecting to the east of the LP system.

Because our beast appears to be decaying doesn't necessarily mean a. it will continue to do that and not reintensify and b. that more won't erupt in its wake!

Have to bear in mind also it is only 11pm...our best chance for action was not forecast until between 1 and 6am so we're not even there yet!

As for UKWW everything I ever see posted on this forum which is pasted from that website, regarding storms and the SE of England it is bloody negative, unless its for anywhere north of London in which case its almost always severe verging on supercellular!

Edited August 22, 2011 by Harry

[cobbettp]

It appears to weakening mid channel, from wot I can see on the Radar

[weatherobsuk]

Look at the gust-front on it though. A line from portsmouth all the way up to Dover could have had the storms energy transitioned inyo this front as its dissipated somewhat, watch for some strong SLWs along these parts of the south coast in the next hour. Especially so given the MCS is likely to prep back up again once it encounters topographic lift from landfall.

[loopydreamer]

It will regain intensity once it hits land folks so don't worry.

villaman is right guys! It will intensify definetly!!!!

[A.J]

impressive new feature going up over Belgium...Looks like a bomb going off!

http://www.sat24.com/gb

[Staffordshire]

Don't mean to dampen your spirits but ut looks like taking a more easterly track than before, but don't worry if it's losing intensity MCS storms pulsate in intensity I belive?

[Robbie Garrett]

Perhaps the more experienced will either agree or disagree, but is that a bowing MCS? It appears to me the front edge is moving out due north ahead of the rest of it - coupled with that it has shown signs of some exceptionally intense rainfall on the leading edge...if it indeed is a bowing MCS (verging into the severe category of storms I'd suggest) then it is likely to be packing some VERY strong winds on the leading edge, not ideal for any boats/ships which may be in the channel....that said, the 'bowing' feature could simply be associated with the winds arching around the LP centre...worth keeping an eye on though IMO

I've spoke to someone on Skype earlier, and he was saying it could be a Gust Front.

Decaying rapidly

http://www.meteox.nl...on=-1.845703125

While the storm across north east france explodes and is possibly dangerous!

Is that a Supercell?