Conv/Storm Discussion 31/5 & Early June

[Darren Bown]

Already at 18C here and rising, very warm, slightly humid no wind whatsoever. I'm watching these Congestus clouds flying up at the moment, some become Cumulonimbus Calvus within minutes of me spotting the congestus. Most activity is to the West of me.

Daz

[Nick F]

One thing to add for the potential this afternoon, is perhaps a greater chance of showers developing over Central Southern England this afternoon W and SW of London, GFS hadn't really picked up on instability in this area on the 00z run, but there is alot of hard convection with towering cumulus over here and to the West of T/Wells - possible convergence line looking at current wind map, 06z has extended the precipitation range now to include South Central England aswell as Western and Northern areas:

Steepest lapse rates look to be over Wales, N. England and Scotland still - so best chance of thunderstorms developing here, but can't rule out heavy showrs with the odd crack of thunder over Central Southern England too. Places most likely to stay dry are East Anglia and upto the Eastern side towards Yorkshire.

[Snowyowl9]

Started with clear blue 1st thing then fair weather cumulus bubbled up to TCu but no showers about yet,not much to the south just cumulus.

It`s 19.1c so warmer already so may see a sharp thundery shower later if I`m lucky.

[SnowJoke]

Nice and wam here today allready hit 20'c in the centre of milton keynes @ 13:00hrs. Just the odd large cumulous floating about at the minute, but the sky looks much clearer than yesterday so any showers that do form look like having a greater chance of absorbing the surrounding avaliable energy. BBC earier were saying the majority of the beefiest showers will be in the midlands once more today, so people need to keep thier eyes peeled as photo opertunities look much better than yesterday afternoon

[Guenhwyvar]

Hello I'm just learning about thunderstorms,And I've noticed that Dewpoints and cape are mentioned regularly.My dew point at the moment is 14.6.Can someone explain to me About dew points and what the best readings are for thunderstorm clouds forming.

Thankyou

[robl1200]

A little off topic, but yesterday a 14 yr old Boy in Manchester was hit by Lightning whilst sheltering under a tree in a park, he has burns to 10% of his body and was knocked unconcious by the bolt.

[Bobby]

Hello I'm just learning about thunderstorms,And I've noticed that Dewpoints and cape are mentioned regularly.My dew point at the moment is 14.6.Can someone explain to me About dew points and what the best readings are for thunderstorm clouds forming.

Thankyou

From Wikipedia:

"In meteorology, convective available potential energy (CAPE), sometimes, simply, available potential energy (APE), is the amount of energy a parcel of air would have if lifted a certain distance vertically through the atmosphere. CAPE values are valuable in predicting severe weather."

As for dew points, they are calculated by an equation involving the temperature and humidity. The higher the temperature and humidity, the higher the dew point and the better it is generally for thunderstorm formation. High cape and high dew points = good for storms.

I see some showers breaking out up the lake district way on the radar, nowt elsewhere though.

Edited June 1, 2007 by Magpie

[SnowJoke]

A little off topic, but yesterday a 14 yr old Boy in Manchester was hit by Lightning whilst sheltering under a tree in a park, he has burns to 10% of his body and was knocked unconcious by the bolt.

That is why you should never shelter under a tree during a thunderstorm. Quite astonishing really how many people take shelter in potentially dangerous places during thunderstorms :unsure:

[Stormraider]

A little off topic, but yesterday a 14 yr old Boy in Manchester was hit by Lightning whilst sheltering under a tree in a park, he has burns to 10% of his body and was knocked unconcious by the bolt.

Dont think he will be wanting to do that again in a hurry.... hope its a lesson learnt.

[Kain]

Bloke in Brum also got hit by lightning - relitively ok though. On the news it said it disintergrated his one shoe!

Kain

[Mad Murdoch]

Dont think he will be wanting to do that again in a hurry.... hope its a lesson learnt.

Trees and lightning just dont mix...

http://www.youtube.com/watch?v=gKPwkau0Dh0

[johnholmes]

Hello I'm just learning about thunderstorms,And I've noticed that Dewpoints and cape are mentioned regularly.My dew point at the moment is 14.6.Can someone explain to me About dew points and what the best readings are for thunderstorm clouds forming.

Thankyou

try this web site

http://homepage.ntlworld.com/booty.weather/FAQ/Glostop.htm

alphabetical and a huge amount of explanations on most things meteorological.

Or go our Guides section

welcome to Net Wx

[karyo]

Apart from some cumulous there's nothing of interest here. Disappointing day!

Karyo

[BrickFielder]

Upper troughs moving slowly eastwards are likely to be focus of any convection as these represent slightly cooler air aloft. High temperatures over central areas may just spark off a seperate isolated storm but don't hold your breath.

Red coloured areas on this satellite picture represent cooler stratospheric air being pulled down into upper levels (Trough).

Satellite pictures available from EUMETSAT

[Guest]

Can anyone shed any light on the storm situation later on Sunday? I know rain is crossing the country from west to east, with minimal storm risk during the day. However, the storm chances dramatically increase from 9pm-12am with 50% risk across the spine of England.

[Stuart]

Not much going on here at the moment but look like we are in for a storm soon :unsure:

[Guest]

Not much going on here at the moment but look like we are in for a storm soon :unsure:

You're in a prime spot today Stuart. Looks like thats where the main storm threat is going to be this afternoon, with just isolated thunder activity further south.

[Shadow]

There are some very dark clouds gathering here and the wind is picking up a wee bit, not sure if we are going to get anything stormy from this today I do hope so as it is feeling very muggy outside. :unsure:

[Noctilucid]

Very heavy downpour here now - no thunder this time though

Tamara

very isolated shower activity has been moving down the coast towards eastbourne, straight over Hastings.

Im currently watching a rather heavy cell over in Flanders that looks to have Kents name on it, also ive noticed that cumulus is starting to congest to my West with some quite dark bases, i think this will go on to produce moderate showers at the mo.

Joe :unsure:

[mackerel sky]

Conditional instability seems to be the order of the day so far by the looks of things, both for the North Pennines and the South Downs judging by the current wind directions and radar. I'd imagine most other areas have similar conditions to here, cloud building but not a huge amount of vertical development. Need a bit of forcing uphill, onshore breezes etc or caps to be broken.

[shuggee]

Not much going on here at the moment but look like we are in for a storm soon :unsure:

It's muggy with quite a lot of building cloud here Stuart - and to our SE it's rather black

[Stuart]

It's muggy with quite a lot of building cloud here Stuart - and to our SE it's rather black :unsure:

but I only had a shower out of that I think net weather lightning detector is worng becuse not seen any lightning yet

Edited June 1, 2007 by Stuart H

[BrickFielder]

Nottingham mid day sounding shows warmer air at 550hPa. 25C + Temperatures required for storms or some cooling of the upper level air.

Can anyone shed any light on the storm situation later on Sunday? I know rain is crossing the country from west to east, with minimal storm risk during the day. However, the storm chances dramatically increase from 9pm-12am with 50% risk across the spine of England.

Its an occluding frontal system. Warm moist air at low level moves in while colder air gets lifted out. Which leaves you with cool air over warm an unstable condition favourable for some isolated deep convection.

[SnowJoke]

Looks like a non stormy day for most of us, the atmosphere is just to stable and temperatures are not high enough to initiate anything thundery. A few heavy showers are approaching the scottish borders but as the days thermal heating generally slows down i think even these will fizzle out. bit of a pants day storm wise, nice though if you like the sunshine

[mackerel sky]

Nottingham mid day sounding shows warmer air at 550hPa. 25C + Temperatures required for storms or some cooling of the upper level air.

I was guessing earlier that we needed temperatures 24C+ inland. Not surprised to see some conditional instability arising from the forcing of warmer air aloft along the South Downs and North Pennines/Cheviots.

Looks like a very nice weekend I have to say for most of England.

Edited June 1, 2007 by mackerel sky