3rd Aug 2011 - Storm/convective Forecast Discusion And Reports

[Costa Del Fal]

As expected i think the Met Office had this one wrong yesterday evening. Im expecting a dry and hot day here. Same set up as yesterday pretty much.

[Supacell]

If I were to chase today, I'd probably pick the M11 north through towards Cambs, looking quite good atm for storm development across western East Anglia Lincs area. Storms should be fairly slow-moving and forming along wind-convergence/sea breeze front that is likely to develop inland across eastern England this afternoon. Given weak winds aloft and convergence - potentialfor some funnel sightings. 00z Herstmonceux ascent shows PWAT (precipitable water) value of 30mm - which is rather high - so some very heavy localised rainfall likely from storms with risk of flash flooding.

Netweather storm forecast for today: http://www.netweather.tv/index.cgi?action=convective;sess=

That is where I will be heading Nick, although coming from the north I would probably pick the northern part of that prediction. I am planning on hanging around South Lincs (A1 area) so that I have easy access north or south.

Problem is, I am unable to get there until around 4pm. What time looks to be best? Will I be too late and miss it?

[Coast]

Problem is, I am unable to get there until around 4pm. What time looks to be best? Will I be too late and miss it?

Timing should be about right. If you have internet access 'on the go', then check in here to see if anything has popped up further to the South and West. I expect the action to peak around 6 to 7ish

[Supacell]

Timing should be about right. If you have internet access 'on the go', then check in here to see if anything has popped up further to the South and West. I expect the action to peak around 6 to 7ish

Thanks Coast.

I have a mobile phone so i can read reports on here, but no access to radar. Should be well placed in the risk area by 6/7pm so fingers crossed.

[bobbydog]

Timing should be about right. If you have internet access 'on the go', then check in here to see if anything has popped up further to the South and West. I expect the action to peak around 6 to 7ish

what do you think the chances are for our area?

[Chris K]

If the Met Office forecast miraculously stays the same for SW England for Sunday I am loving it.

[Coast]

what do you think the chances are for our area?

I'm going to say slim I'm afraid. There is a hint of something later. but not all those ingredients come together for us at the same time. 12z Herstmonceux sounding will be the tell-tale, but be prepared to watch our neighbours to the North East and in France / Benelux get the light and sound show.

Current (overnight) sounding has nothing inspiring:

[Wivenswold]

Got very excited there. Big boom to the south. Then I remembered that the MOD often 'dispose' of bombs on Foulness Island during the week.

[bobbydog]

I'm going to say slim I'm afraid. There is a hint of something later. but not all those ingredients come together for us at the same time. 12z Herstmonceux sounding will be the tell-tale, but be prepared to watch our neighbours to the North East and in France / Benelux get the light and sound show.

i thought as much. but you never know, some of the best storms i have seen have come out of nowhere!

[Coast]

i thought as much. but you never know, some of the best storms i have seen have come out of nowhere!

Here's hoping!

[VillagePlank]

[London/Kent/ESussex]

Here's the skew-T s for the afternoon, for London-Heathrow, GFS 00z run,

As there isn't much chance of any other triggering factors, we must look at the surface heating induced convection trigger (ie the surface becomes so warm that convection is triggered) The magic Theta-W where this initiates is 22C. Here's the analysis,

12z->22C, based on T=25C

15z->22C, based on T=25C

18z->21C, based on T=22C

This is right on the margins, and accounting for rounding errors, and other approximations, could be ever so slightly either side. Also, GFS seems to be under doing the temperatures, somewhat, the higher the temps given that the dew-points remain the same, the better the chance of surface initiated convection there is.

If showers form, then what's the chance it will be thundery? It comes in around 71% based on K-Index, and Total Totals. ie for every ten showers that form seven of them should be t/storms.

The problem is - will showers form?

GFS has it for the NW of the region leaving most of Kent and E Sussex dry, hot and humid.

As for me (in Rochester) - I will feel lucky to see a shower, today, let alone a thunder-storm. Perhaps a nice surprise for those on their way home from work from Central London at approx 5pm-7pm.

Edited August 3, 2011 by Sparticle

[Jane Louise]

Tony Gilbert has updated the forecast from last night by extending the risk box over to the West more !

Now, I could be in for a chance today Lol.

Had some Altocumulus Castellanus clouds earlier so fingers crossed.

UPDATE 9.10am Weds

AS per earlier forecast with general risk box extended west and stronger convective box extended north as per map below. More inline now with Paul's convective map!

Both GFS and NMM push the strongest instability and convergence further north than earlier runs. Concerns remain regarding cloud cover today whereby some delay for convection is possible. Certainly much later than the GFS are currently predicting. GFS now increase dew point temp 2 deg higher that the 18Z run yesterday which is a positive factor. Though all in all I would expect primarily high based storms today.

Edited by Tony Gilbert 3/8/2011 09:22

http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=44242

[Paul Sherman]

Would love to be chasing this today but alas 3 Kids on Summer Holidays means have to stay in Stormless Leigh On Sea

Would favour the A14 Corridoor today, and use it as a slide rule along any Convergence Zone type Storms that should be lined up SW-NE From North of London up towards Lincolnshire, that way staying out of the precip and watching for CZ Funnels and seeing Cg Lightning more easily with the Sun behind the Line of Storms!

Should be quite an easy chase for any people chasing today as the Storms will give the impression of Back Building (Eg not moving anywhere fast)

Good luck and want to see some cracking convection pictures later from the chasers!

Paul S

[pinball wizard]

Would love to be chasing this today but alas 3 Kids on Summer Holidays means have to stay in Stormless Leigh On Sea

Would favour the A14 Corridoor today, and use it as a slide rule along any Convergence Zone type Storms that should be lined up SW-NE From North of London up towards Lincolnshire, that way staying out of the precip and watching for CZ Funnels and seeing Cg Lightning more easily with the Sun behind the Line of Storms!

Should be quite an easy chase for any people chasing today as the Storms will give the impression of Back Building (Eg not moving anywhere fast)

Good luck and want to see some cracking convection pictures later from the chasers!

Paul S

Given this and your post yesterday evening, I can't help but think that here in Bury St Eds I could end up in a sweet spot today.

[Coast]

Given this and your post yesterday evening, I can't help but think that here in Bury St Eds I could end up in a sweet spot today.

I think you could well be! Surface heating/temps should help things today and so these purple patches may be an indicator:

[Paul Sherman]

Given this and your post yesterday evening, I can't help but think that here in Bury St Eds I could end up in a sweet spot today.

Absolutely

If I was picking a chase target today Bury St Edmonds or somewhere like Saffron Waldon would be my Pick

[Supacell]

Sunny skies here but some convection starting up. First sunny start of this warm spell.

But I will be heading South and East this afternoon as I do not anticipate Bradford to be as well placed as areas to my SE.

[Coast]

OK, if we are going virtual, (as I'm giving blood later!) I'll go for an area here:

[TheToastPeople]

OK, if we are going virtual, (as I'm giving blood later!) I'll go for an area here:

so fudging close im not going to see a thing !

Edited August 3, 2011 by Daveweiser

[daggerdanny]

Any thoughts for Sheffield area? Playing golf there today and dont want to be clobbered by lightening!

[NorthNorfolkWeather]

OK, if we are going virtual, (as I'm giving blood later!) I'll go for an area here:

I think I'd move it 20 miles west from there with Peterborough being smack bang in the middle. Have a feeling Norwich will not get anything

Could be wrong.......

[Stuart]

I have no chances

[Joneseye]

Some fairly tasty temps already in the 'sweet spot':

http://www.netweather.tv/index.cgi?action=daily;type=maxt

I feel that the same as yesterday that my area will be the provider rather than the benefactor with the steering winds from the south/south west. We have some comparable temps with this time yesterday according to my local weather station. If anything the humidity and dew points are higher:

http://www.thatcham-weather.info/

[gottolovethisweather]

Parents are in north cornwall and they are witnessing many cloud types developing, cumulus/altostratus and possible anvils out at sea.

As this area wasn't particularly in the storm forecast zone it will be interesting to see what transpires from them.

All of these developing cells are showing up well on v5 netweather radar, just off the coast.

Cheers

gottolovethisweather

As of 1010BST 18.9c AT, 18c DP and plenty of sunshine in Newbury, Berkshire

Edited August 3, 2011 by gottolovethisweather

[NO LONGER POSTING]

I know tomorrows rain is not going to be thundery..But looking at it ..Going to be very wet across the south east..inch and a half of rain in some places..With the ground so dry and heavy rain in a short time could lead to some flash flooding??