Storm & Convective Discussion - 16/07/15 onwards

[NO LONGER POSTING]

The actual conditions for thunderstorms are literally touching the coast now.. IF we can get the cloud to break a tad I think we will be game on (south) 

[fine wine]

With predicted highs of 27c (00z gfs) across the south then there is no reason to be so downbeat. Also gfs usually underestimates highs by 1 - 2 c.

[sunnijim]

The Met Office were still saying yesterday that this thundery Low was a very tricky one to get the forecast detail correct on.

Certainly this is coming to pass!

Light rain over London now and storm forecast replaced by "more showers later"

[Gordon Webb]

just saw the breakfast forecast with Carol K and she indicates that these storms will more north very very slowly only reaching the birmingham area by 5pm and be hit and miss at that then another another system moving north over the north sea this evening looking at that forecast and models the rain doesn't look particulary threatening even though I expect locally some will get heavy rain considering that the forecast for last night had rain over me by 8am this morning this is a serious change and I wouldn't get hopes of much sunshine as if there's no rain there's going to be a lot of cloud

[NO LONGER POSTING]

I can't get over how slow those storms are damn!

[Gordon Webb]

With predicted highs of 27c (00z gfs) across the south then there is no reason to be so downbeat. Also gfs usually underestimates highs by 1 - 2 c.

 

yep but the precipitation charts on that run are ot really that devastating apart the south coast and later the SE but that could be the system Carol K said move n over north sea coast this evening

 

reminds me of a forecast a few years ago when all this was forecast day turned out to be cloudy and by the time the afternoons forecast were rolling in it was downgraded to such an extent it was only light rain

 

now i'm not saying that this will happen today but a few posters on here and the model forum over the last few days have cast doubt on the amount of thunder associated with this even though they all said some is likely I just hope some are NOT let down again

 

edited to add the word NOT

Edited August 13, 2015 by Gordon Webb

[Spikecollie]

I know I should probably be on the European convective area, but just to reassure you, things are slow here in France other than in the north. It seems our storms here in Limousin will come in a second wave this morning, up from the south. All we've had so far is a few hours of heavy rain - but the storms will come.

[dec10snow]

The Met Office were still saying yesterday that this thundery Low was a very tricky one to get the forecast detail correct on.

Certainly this is coming to pass!

Light rain over London now and storm forecast replaced by "more showers later"

Well it still is apparently, Fergie has just tweeted this:

@fergieweather: W COUNTRY 0800 Still mostly dry across region. Risk of heavy rain grows later, but UKMO stress low f'cast confidence http://t.co/Y3bBJnqPUJ

So they don't even know if there's going to be heavy rain later, and this is 12 hours or less out!!

[Gordon Webb]

I can't get over how slow those storms are damn!

 

if you saw the bbc breakfast forecast they had only just reached oxfordshire by 4-5pm and the radar returns then were far from spectacular the rain band expected to form over the west and into scotland looked to have more on it for tomorrow

[1976]

Well, I waited and waited and er waited, saw the huge blob on radar approach painfully slow, felt wind pick up, heard distant rumbles, waited some more and gave up at 1:30am - had nothing all night bbq got about a teaspoon of precipitation in it !

Just a normal night camping down in hayle cornwall !

So close, but so far !

[Fitzwis]

Morning all (after a very late night!) 

 

Does anyone know where we could find or does anyone have the data of the average lightning strike rate for Jersey's storm between 23:30 last night and 02:30 this morning?

 

It would be interesting to find out as the reality was exceptional to say the least 

 

Here's to round 2 predicted for later today and tonight 

 

Oh, and here's a picture by Nick Venton (shared on his facebook page) taken from Noirmont Point (where we were) as the storm approached late last night 

 

Edited August 13, 2015 by Fitzwis

[NO LONGER POSTING]

Morning all (after a very late night!) 

 

Does anyone know where we could find or does anyone have the data of our average lightning strike rate for Jersey's storm between 23:30 last night and 02:30 this morning?

 

It would be interesting to find out as the reality was exceptional to say the least 

 

Here's to round 2 predicted for later today and tonight 

 

Oh, and here's a picture by Nick Venton (shared on his facebook page) taken from Noirmont Point (where we were) as the storm approached late last night 

 

Jersey Lightning - Nick Venton Photography.jpg

 

That is just stunning... Im struggling to think of a UK photo coming close to this IMO

the colors :O 

[Nick F]

Storm & Convective Forecast

 

Issued 2015-08-13 07:20:44

 

Valid: 13/08/2015 0600z to 14/08/2015 0600z

 

CONVECTIVE / STORM OUTLOOK THURS 13TH AUGUST

 

Synopsis

Increasingly amplified upper flow, as the upper trough over the N Atlantic disrupts against upper ridge over central/eastern Europe, with a cut-off upper low (visible on WV imagery) over the Bay of Biscay moving NE towards southern UK/N France today. The flow has backed Sly at mid-upper levels to SEly at the surface. An area of surface low pressure over N France drifts N across S England on Thurs evening. Associated warm front and shortwave trough behind it will lift north across S England/S Wales Thurs morning, with some thundery activity along it, cold front pushes north across S England by 00z Fri.

 

... WALES, S ENGLAND, MIDLANDS, E ANGLIA ...

 

Differential thermal advection and shortwave trough rounding upper low to the SW continues to destabilise high thet-w plume pushing N to produce elevated thunderstorms over the English Channel and along southern coastal areas of England early this morning, these storms will spread north across the above areas through the rest of the morning, though lightning activity and any severe threats will tend to wane as the storms move towards Midlands where instability will be weaker. There is some uncertainty of northward extent of these storms too. These storms will be well organised, with multicell clusters the main mode, these storms capable of producing torrential rain leading to localised flooding (rainfall rates of 40-60mm locally possible), hail, strong wind gusts and frequent cloud-to-ground lightning. A broad MGNL risk has been given for these areas

 

Drier conditions may move in across S England and E Anglia this afternoon, the warm and humid airmass will probably remain capped to surface based convection developing, given high convective trigger temperature required, though forcing for ascent with approach of upper low/vortex currently over the Bay of Biscay and surface cold front combined with high temperatures over N France will likely trigger surface-based storms here, which will tend to drift towards central S and SE England this evening, This storms will, again, be capable of producing severe weather threats of torrential rainfall leading to flash flooding, isolated large hail, damaging wind gusts and frequent cloud to ground lightning. Therefore have issued a SLIGHT risk for central S/SE England and E Anglia.

 

Edited August 13, 2015 by Nick F

[Woollymummy]

If it did get to Oxfordshire I was obviously too sleepy to notice, still am,I am definitely going to water the garden and plan a big picnic day out for today as if nothing was going to happen to the weather.....

Glad to see the lovely pic from Channel Islands!

Edited August 13, 2015 by Woollymummy

[East_England_Stormchaser91]

Heres Estofex's verdict on the current situation:

 

 

A level 1 was issued for England mainly for excessive precipitation and to a lesser extent large hail.

 

DISCUSSION

North-eastern France into western Alps, central Germany, Benelux, and England

A plume of evelvated lapse rates spreads northward ahead of an approaching cold front. Given quite adequate boundary layer moisture and strong diurnal heating, MLCAPE of more than 1000 J/kg is possible. First storms are forecast along the Channel region where warm air advection is strongest, but more storms are expected to form over the western Alps and western/central Germany as well as along the cold front over eastern and northern France. In the evening hours, linear organized storms are expected along the cold front from the western Alps to south-east England.

Vertical wind shear remains rather weak, but increases in the evening especially at low levels over the Benelux region and England. Best potential of organized convection is expected over the Benelux countries, where bow echoes may form along the linear squall line of the cold front. Severe wind gusts are forecast with these storms. The threat spreads into western central Germany later on, where pre-frontal storms can merge to the line. Weakening instability will reduce the threat after sunset. Isolated large hail and tornadoes are not ruled out, especially when supercells can form ahead of the squall line. Over England, storms may be elevated due to a colder boundary layer. Excessive precipitation is expected to be the main threat, but isolated large hail cannot be ruled out, especially in eastern England.

Further south, clusters of storms are expected over the western Alpine region. 15 to 20 m/s deep layer vertical wind shear will assist well developed multicells and supercells, capable of producing large hail, excessive precipitation, and severe wind gusts. Weakening storms will move into southern Germany during the night, where severe threat will gradually decrease.

[NO LONGER POSTING]

Things in the channel are hotting up a little so to speak..

[Gordon Webb]

 

 

 

 

 

taken at face value does'nt look as bad as could be

[dave reid]

Morning all.

Got the day off and car so chase is on but to stay put in Bournemouth or head east?????

Good luck everyone

[Flash bang flash bang etc]

The sea in the channel must be really flooded this morning, Wow

Edited August 13, 2015 by Flash bang flash bang etc

[NO LONGER POSTING]

Morning all.

Got the day off and car so chase is on but to stay put in Bournemouth or head east?????

Good luck everyone

 

Looking at that thing leaving France if it gets even half way I would be heading east.. It's a MONSTER 

[Gordon Webb]

Morning all.

Got the day off and car so chase is on but to stay put in Bournemouth or head east?????

Good luck everyone

 

depends when your chasing if it's this evening IF I had the nerve to chase I'd go further east there's plenty in the channel at the moment but that's expect to weaken as it moves north and there's even a question mark of how north it gets

[tcc]

Had some thundery rain around 4 am which woke me up and then heavy rain for another couple of hours, been dry since 7am but looks to be more heavy rain on it's way!

[cotswoldsnow]

looking at the latest, i think there maybe a little disappointment for some. as usual its all been a tad overhyped. hope im wrong

[dave reid]

 

Looking at that thing leaving France if it gets even half way I would be heading east.. It's a MONSTER 

indeed it is

 

depends when your chasing if it's this evening IF I had the nerve to chase I'd go further east there's plenty in the channel at the moment but that's expect to weaken as it moves north and there's even a question mark of how north it gets

I've got until 5pm this eve when I have to be back to pick up girlfriend from work.

 

Any suggestions on good view points should I head east?

[Callie]

More rumbles starting around here!