Upcoming Convective / Storm Risk Discussion - w/c 12th May

[Stuart]

you nerver khow GFS might have it worrng

[Coast]

Don't think it looks that quiet Robin, particularly tomorrow going by the Met Office forecasts, though nothing severe. I think GFS maybe not picking up the potential today and tomorrow, though it maybe because it is simulating alot of cloud cover suppressing convective potential.

 

I do rely on the GFS output too much it's true Nick, it seems to cover more variants of the convective forecast further out and I inevitably latch on to those particular charts first off. I need to look at other models (especially or own NMM) more often!!!

you nerver khow GFS might have it worrng

 

Never been said before Stu!!! 

[Coast]

I do rely on the GFS output too much it's true 

 

As if by magic, the NW Extra NMM charts for this afternoon appeared.......

 

 

 

 

Skew T for Aberdeen shows the best time today is around 18.00 hrs

 

[Stuart]

Thanks Coast for that keeping my fingers and toes cross

[East_England_Stormchaser91]

Looking like a fair chance of a few storms into next week as a sporadic low pressure looks to sit right on top of us and moving in no great hurry. 

Good chance of a few lively torrential downpours in places with perhaps local flash flooding judging by the charts. 

About time we had some proper Countrywide lively storms !

[Karl83]

Looking like a fair chance of a few storms into next week as a sporadic low pressure looks to sit right on top of us and moving in no great hurry. 

Good chance of a few lively torrential downpours in places with perhaps local flash flooding judging by the charts. 

About time we had some proper Countrywide lively storms !

Yep. Has shown a lot on GFS now. Here's hoping mate!

[VillagePlank]

In the meantime, the SE looks reasonable for tomorrow,

 

 

Small convective potential (KI/LI), but where it does fire, it looks like widely scattered thunderstorms (TT/CAPE)

[Coast]

One little sferic on the NW detector in NE Scotalnd an hour ago, but otherwise quiet currently. Still a couple of hours left for a few more.

 

http://www.netweather.tv/index.cgi?action=lightning;sess=

In the meantime, the SE looks reasonable for tomorrow,

 

 

Where's that for Sparky?

[VillagePlank]

Heathrow - TT's quite impressive for UK, I thought Will be very interesting to see if the Herstmonceaux ascent matches the forecast!

[Sprites]

I must of missed the Mr Ben NMM charts episode, i always liked Mr.Ben when i was little, moderate rain here atm.

Edited May 22, 2013 by Sprites

[Coast]

Heathrow - TT's quite impressive for UK, I thought Will be very interesting to see if the Herstmonceaux ascent matches the forecast!

 

Lets hope it does and follows through, Herstmonceux is about 4 miles from my house!

[Convective]

I certainly see what you's are seeing! 

 

[Stuart]

Now that looking nice chat for widespread storms but long way off

[Supacell]

Although a low risk as most of the storm activity will be out in the North Sea, there is a risk of thunderstorms down the east coast through the night time hours. Very high lapse rates, high TT index and a small amount of CAPE are all in place just offshore, with the main risk area sliding down the east coast through the night and reaching northern Norfolk by around 5am.

 

Certainly if not thunderstorms along the coast, there will probably be flashes visible out to sea during the night time hours.

 

 

Already sferics across NE Northumberland and some very heavy downpours out to sea in the NE.

[Convective]

Fairly interesting setup here at the moment. Large building cumulus clouds starting to develop however it seems as though there is an inversion stopping further development however higher up there is some thick cloud, just that there's this boundary between both. Just had a shower from nowhere too with very, very ominous clouds building all around! Some very dark bases all around me! BBC have hail forecast for here later too. We'll see

[NL]

Currently under a heavy hail storm accompanied by strong winds, no thunder and lightning but quite impressive nonetheless.

[Geordiesnow]

Currently under a heavy hail storm accompanied by strong winds, no thunder and lightning but quite impressive nonetheless.

 

Was just on the outskirts of that shower around here, could see the jet black skies to my East, did threaten to get interesting here but nothing more than that really. No hail recorded here also unfortunately.

[Cloud 10]

Got some decent sized hail falling here at the moment.

 

 

edit.nice rumble of thunder just now!

Edited May 22, 2013 by Cloud 10

[Tamara]

If this was winter then tomorrow and Friday would appeal much more  and the mini snow white-outs and the cloudscapes on the coast looking out to sea etc would compensate for my new found thunder allergy

[paul m]

Just heard a very distant rumble of thunder. Can anyone confirm where the strike was as map I'm using not showing its location. First rumble of the year...

[Stuart]

next week still looking good for wide spared storms

[Coast]

Morning storm fans, lets see what the charts and stuff say we have in store today then.

 

Lots of activity throughout Europe according to ESTOFEX this morning, but our area of interest has some consideration from them on their forecast map:

 

 

Storm Forecast

Valid: Thu 23 May 2013 06:00 to Fri 24 May 2013 06:00 UTC

Issued: Wed 22 May 2013 23:00

Forecaster: GATZEN

A level 2 was issued for central Romania mainly for large hail and severe wind gusts and to a lesser extend for tornadoes.

 

SYNOPSIS

 

An amplified long-wave trough remains over Europe and re-intensifies as a new short-wave impulse leads to cold air advection across western Europe. Ahead of the trough, an unseasonably strong jet streak will travel from the south Mediterranean across Greece and Turkey into the Black Sea during the period. Downstream, a negatively tilted short-wave trough will move northward across western Russia.

 

Belgium into western Germany

 

Mid-level cold air and a surface low pressure center will affect Belgium in the morning hours. Latest GFS indicates a tongue of moisture near the low center overlapping with steep lapse rates that develop due to diurnal heating. Showers and thunderstorms are forecast that will spread eastward during the day. The set-up with moist and buoyant low-level air and weak vertical wind shear may support tornadoes. Marginally large hail is also possible with the stronger storms. Main limiting factor will be reduced low-level heating due to the cloud coverage.

 

All the other storm sites are 'forecastless' so far this morning, so straight into some charts:

 

GFS overview back up the ESTOFEX forecast with small storms in Belgium and rain mostly down the Eastern side of the UK:

 

 

 

Lightning Wizard GFS based charts show low levels of MLCAPE from the Midlands South:

 

 

 

But stronger levels of SBCAPE:

 

 

There's an interesting feature down int he SE Corner this afternoon:

 

 

With a bit of rain:

 

 

 

and meaty lapse rates:

 

 

Now for the NW Extra NMM versions:

 

 

 

Now I know we are going to debate the TT index and it's validity for ever!, but here it is for thought and look at that SE corner!

 

 

Low risk generally, higher in Kent and East Sussex later maybe? I shan't have a chance to chase in the early evening as I have to have a ruddy scan at the hospital, but maybe the skyscapes will be interesting on the way in.

[Coast]

Skew T soundings for Herstmonceux this afternoon not totally encouraging at the moment:

 

 

 

 

 

 

 

 

 

 

[VillagePlank]

Heathrow a downgrade this morning, as well,

 

 

with positive LI, and low KI it looks like showers will form but are unlikely to be thundery, although ruling one out seems a little premature. Incidentally, I use TTs not for an indicator of t/storms formation, but as a guide to their severity should they form.

[Coast]

Quite a bit of hail here in mid Sussex right now.