Convective Outlook

[dave48]

Yeah, some nice looking showers, probably some hail in them. Will most likely decay as they make their way inland, though the odd few heavy showers could develop just about anywhere towards the west.

Agreed, you can already see significant decay over the last few radar runs, will be interesting if anything fires up again over land. It might just be odd heavier showers and then only really stronger stuff appearing again in the south east tomorrow.

It seems we spend the whole summer having thunderstorms killed by water and the winter having them killed by land!

[Cookie]

just got a thunderstorm email from the local weather station

Active warnings:

- CLOSE STORM WARNING

Close alarm range: 250 mi

Expanded info:

TRAC ID J-3100

BEARING 206.1 dgr

RANGE 235 mi

STRIKE RATE 1/min

PEAK RATE 4/min

CATEGORY WEAK

TREND NO CHANGE

Short info:

ID:J-3100 BNG:206 RNG:235mi CAT:WK SR:1 PR:4 TR:NC

Trigger configuration:

Close alarm mode: TSentry

Close alarm range: 250 mi

Severe storm alarm: Enabled

Severe stormcell alarm: Enabled

not 5 mins later I find this email

all clear issued gutted

Notification issued on Sun Nov 22 00:23:39 2009

------------------------------------------------------

No lightning activity detected in 20 minutes

Total time under alert: 1 h 34 m

Edited November 22, 2009 by cookie

[dave48]

I think tomorrows chances for parts of south eastern england, particularly on the south coast itself look great around midday, susprised there hasn't been a bit more excitement about it to be honest.

Good bit of instability and of course a well sheared environment, so all fun and games on that front. Not to mention the fantastic numbers with regard to vorticity and velocity, a really clear and well defined band of strong lift going straight over the relevant area. I would not be at all be surprised if we see some thunderstorms with severe weather reports, gusty winds look likely and of course with that kind of LLS, a tornado.

[Cookie]

I think tomorrows chances for parts of south eastern england, particularly on the south coast itself look great around midday, susprised there hasn't been a bit more excitement about it to be honest.

Good bit of instability and of course a well sheared environment, so all fun and games on that front. Not to mention the fantastic numbers with regard to vorticity and velocity, a really clear and well defined band of strong lift going straight over the relevant area. I would not be at all be surprised if we see some thunderstorms with severe weather reports, gusty winds look likely and of course with that kind of LLS, a tornado.

thanks for posting that going to be an interesting 24 hours all in all and the best place will be right here on netweather if you're not close enough to the action like me.

just got email again about thunderstorm off the coast of Ireland.

Edited November 22, 2009 by cookie

[Cookie]

A TORRO TORNADO WATCH (RED AREA) has been issued at 00:01GMT on Sunday 22nd November 2009

Valid from/until: 05:30 - 15:00GMT on Sunday 22nd November 2009 for the following regions

Parts of (see map)

SW England

Cent S & SE England

S & E Midlands

E Anglia

Channel Islands

THREATS

Tornadoes; wind gusts to 65mph; hail 10-15mm diameter, locally 20mm; CG lightning

DISCUSSION

Within the broad unstable rPm airmass coving the British Isles, a short-wave trough and associated surface moisture plume will overspread the WATCH area later tonight and through tomorrow morning. This will bring an area of showers and thunderstorms across. Deep layer shear will be sufficient for organised cells, perhaps with mesocyclones, and supercells are possible, with reasonably large hail possible. In addition to this, backing of surface winds ahead of the trough will increase low-level shear. This looks like bringing the risk of tornadoes, especially in southern coastal counties and the Channel Islands, where instability will be higher. Inland areas, but the risk is lower than closer to the coast. Some mesoscale models show 55 knots of SW'erly flow at 850 hPa atop 15 knot southerly surface flow. Such shear leads to the chance of a stronger tornado (T3-4). In addition to the tornado/hail risk, winds may gust to 65mph with stronger cells.

Forecaster: RPK.

[weatherobsuk]

More Convective activity into the early hours with a S-Signature North of Bournemouth, some high ppn totals around Southampton and Portsmouth aswell as Sferic activity ongoing around South/Central Wales.

The band of Multicells are looking to just miss Cornwall now, on-track to hit Brest in France instead, some Sferics from this region also coming up on the NW radar.

[Lightning Ed]

Hi Guys/Gals,

Umm Warlingham Surrey is where I'm at and I just heard the most loud clap of thunder possibly of this year. I need new underwear... Gap from flash to bang was approx 1 sec so it was close... Woah...

What is going on with all this mad weather!!

Edited November 22, 2009 by Lightning Ed

[Neilsouth]

Whites now showing up on the radar to the south!

[SteveB]

Has net-weather got a convective forecast for today?

Torro have upgraded their warnings.

http://www.torro.org.uk/site/forecast.php

[Mike Storm]

Heavy line of showers heading for London and the southeast, some red echoes on its southern edge!

[johnholmes]

Has net-weather got a convective forecast for today?

http://www.torro.org...te/forecast.php

not that I know of but I've not seen either Nick F or Brick about and they are the ones who prepare them.

The only comment is mine in my blog.

[BrickFielder]

Having a quick look and there is a interesting trough coming in behind what is probably a cold front. Radar is also showing a potential convective line in the front moving across the south coast.

I need to have a closer look to assess the potential.

[Neilsouth]

We just had an amazing gust of wind , tree's swayed... telephone cables bouncing up and down , leaves all over the place

[Flash Elvis]

There was amazing gust of wind last night about 4.20am last night in Rayleigh then an amazing amount of rain for about 30 secs, seemed so weird as the roof was going mad, yet all the tree's and plants on the ground seemed still

[Snowman15]

We actually got a thunderstorm here in East Dorset last night about 4.00am! a few big flashes of lightning

[*Stormforce~beka*]

Got woke up at 430am? by 3 huge rumbles of thunder and saw bout 3 flashes of lightning.

Huge wind and rain about 6. Nowt afaik since but I just got out of bed ...

[Devon-Nelly]

There was some flashes and rumbles to the south of here at about 1-2am this morning (i think it was probs coming from the south devon coastline) but nothing overhead, but we did get a sporadic torrential downpour with petty pois sized hailstones.

[wallopweather]

Brief thunder storm here at 4am this morning, one large bolt of lightning looked like it hit metal containers used by workmen renovationg our village hall (the type used on container ships) Reports of marble sized hail and localised flooding from people in Salisbury from around breakfast time this morning.

Edited November 22, 2009 by wallopweather

[coldfingers]

Hi cookie,

Not seen any tornados yet :unsure: but we have had winds gusts to 56 knots or 64.4 mph. So pretty wild at times.

Edited November 22, 2009 by coldfingers

[coldfingers]

Woken by thunder at around 4:30 am but only heard the one lot. Very windy today and extremely gusty at times with a max gust at around 11:40 am of 56 knots 44.4mph.

[SteveB]

A couple of short sharp showers passing through, not storm activity yet.

[SteveB]

Amazing squall just passed through, they are faily scary when they hit, certainly pack a punch.

Edited November 22, 2009 by SteveB

[BornFromTheVoid]

Looks like some thunderstorms around 50-100km north of me through central Ireland.

Wind really on the up here now, gusting close to 70km/h

[MP-R]

Amazing squall just passed through, they are faily scary when they hit, certainly pack a punch.

Yes it came through here as well, horizontal torrential rain and slushy hail on a very strong wind. Highest gust was 44mph. I'm surprised you didn't report thunder as I definitely saw a flash just before the squall hit. Some pretty tropical like rain fell vertically after the squall had passed too. Now a nice river running down the edge of the road.

[SteveB]

Yes it came through here as well, horizontal torrential rain and slushy hail on a very strong wind. Highest gust was 44mph. I'm surprised you didn't report thunder as I definitely saw a flash just before the squall hit. Some pretty tropical like rain fell vertically after the squall had passed too. Now a nice river running down the edge of the road.

Didn't see any lightning or hear thunder, but was spectacular non the less.

I really need to get my anemometer higher up. Currently on a 12ft pole in the garden, max gust since I had it set up in April this year is 27mph.

Problem with putting it up on the roof is, getting a long enough cable and tracing it back to the ground station. And I really don't fancy getting up ladders to the apex of the roof.