Convective/Storm Discussion Thread - 1st August onwards

[LightningLover]

UPDATE 19:21 UTC Minor changes to the map, but broad themes remain - update mainly to add commentary. Still a muted signal in some NWP guidance for a few isolated elevated showers / thunderstorms across S/SE England later in the night - confidence not particularly high given dry mid/upper levels which may inhibit deep convection.

http://www.convectiveweather.co.uk/forecast.php?date=2017-08-28

[Allseasons-Si]

There is a couple of cells that have developed south of the channel islands,the key watch area

off to noddy land now,good luck to those in the SE

kent clipper spings to mind.

Edited August 28, 2017 by Allseasons-si

[tomp456]

Are we going to get a storm tonight?

NO

 

Reverse Psychology 

bring on the storms 

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Tue 29 Aug 2017 - 05:59 UTC Wed 30 Aug 2017

ISSUED 22:42 UTC Mon 28 Aug 2017

ISSUED BY: Dan

... SE ENGLAND ...

A lot of uncertainty surrounds developments here throughout Tuesday, tied-in primarily to the potential for elevated shower / thunderstorm activity along the steep Theta-E gradient. Models are handling the exact location/orientation of this Theta-E gradient slightly differently, along with subtle forcing features which ultimately has a knock-on effect as to when and if destabilisation occurs, and whether it is over UK land or offshore.

Some activity may be ongoing at the beginning of this forecast period over SE England, which could extend up the eastern side of East Anglia during the morning hours - but far from certain. Further bursts of medium level convection may occur at various times through the day, so an ongoing threat of isolated to scattered  thunderstorms seems possible at least close to the coasts of SE England and East Anglia, though most NWP output keeps the vast majority of any developments offshore. A tentative SLGT has been issued to best highlight the areas at greatest risk (though considered fairly low even here). Notably dry mid/upper levels may inhibit deep convection from developing.

 

... N / NW SCOTLAND ... 

Broad upper trough approaching from the Atlantic will introduce steeper lapse rates and a deep convection regime to northwestern areas, particularly later and overnight into Wednesday. Some sporadic lightning and gusty winds will be possible from scattered heavy showers.

 

http://www.convectiveweather.co.uk/forecast.php?date=2017-08-29

[Nick F]

A few heavy showers popping up across the SE, though no sferics, tower to my SE near Croydon

[Nick F]

Brief heavy shower passing over here near Croydon, blue skies to the south, better shot of the London convective skies (earlier) in the tweet below

 

[alexisj9]

Sky looks interesting from time to time here, but nothing happening.

[LightningLover]

No thunderstorms...

[Flash bang flash bang etc]

Skies look like they could but they probably won't

[Nick F]

Storm & Convective Forecast

Issued 2017-08-29 09:20:33
Valid: Tues 29th Aug 6am to Weds 30th Aug 6am

Day 1 Convective / Storm Forecast

Synopsis

An upper trough axis lies SW to NE across the far NE Atlantic and a cut-off upper low sits over Iberia to the west of an upper ridge over central, southern and eastern Europe. At the surface, a weak cold front will slide slowly SE across England and Wales, with a warm and huimid airmass across SE UK and an unstable showery flow across NW UK. A shallow area of low pressure covers the near continent which will deepen slightly and bring an area of heavy and perhaps thundery rain across SE UK tonight.

... SE UK ...

The NW edge of a plume of very warm and humid airmass residing on the near continent will sit across SE England today and overnight. Isolated elevated heavy showers, perhaps with sporadic lightning, may occur where Ac cas becomes deep enough with subtle forcing along NW edge of plume. Otherwise, overnight there is an increasing risk of embedded elevated thunderstorms within pulses of heavy rain developing and moving NE from N France / East English Channel across SE England ... as baroclinic zone and surface convergence developing over northern France in response to falling heights/temps from the NW create increased ascent of plume over near continent. There is a risk of minor localised flooding from these storms, mainly Sussex and Kent overnight.

... N. IRELAND and W SCOTLAND ...

With steepening lapse rates from the NW, as upper trough / cold pool slides SE, convection may become deep enough amongst the showers expected here to produce sporadic lightning and small hail.

Issued by: Nick Finnis

[alexisj9]

Sky still looking more interesting, the ac cas is getting a bit bigger. Still don't think anything will happen yet.

[LightningLover]

1 minute ago, alexisj9 said:

Sky still looking more interesting, the ac cas is getting a bit bigger. Still don't think anything will happen yet.

What about tonight? Accuweather says: "A heavy thunderstorm or shower"

[LightningLover]

I *might* stay up tonight, depending on developments today.

[alexisj9]

I will be up till about 2 either way, normal time i go up. However if anything decent kicks off, i'll stay awake.

[Julian 777]

Me too  .. Hope we get something down here in these parts..This could well be the last throw of the dice for plume associated storms..Or will it? have known some stormy Septembers in years gone by...Good luck everyone!!

[Thunderstruck]

Incredibly humid here, very uncomfortable out. Sky very milky, with the odd bit of ac cas. 

Not ruling anything out...

[alexisj9]

5 minutes ago, Jcweather said:

Incredibly humid here, very uncomfortable out. Sky very milky, with the odd bit of ac cas. 

Not ruling anything out...

My ac cas has disintergrated, however the sky is milky, and the humidity and heat, very oppressive.

[Windblade]

Haven't been around the past few days as no storm potential for my area. Just unbearable, hot, sticky, uncomfortable, sweltering, boiling, disgusting heat.  Thankfully, it looks more promising (and cooler) for the rest of the week where we have some potential storm activity. Will be keeping an eye on the radar and the skies and hope we get something. Still waiting for my first fork lightning of 2017 (everything I've witnessed so far has all been IC). Tonight looks particularly favourable but lets see how things develop. Fingers crossed. Good luck to all. 

Edited August 29, 2017 by Windblade

[LightningLover]

Ac Cas spotted! (It's unbearably humid too, with white milky skies)

[stainesbloke]

http://tapnewswire.com/2017/08/millions-of-trees-blown-down-in-massive-hurricane-no-news-reporting-why/

Interesting and sad article about millions of trees flattened in Poland from recent storms, causing 6 deaths unfortunately. Nothing reported in our media, surprise surprise.

[Callie]

Suddenly clouded over with cloud definition visible and very still, feeling very humid

[tomp456]

23C, 18C dew point, 75% humidity.

Minging. 

 

Bring on the rain tomorrow! 

[tomp456]

The food is here, just wish mother nature would eat it!

 

[LightningLover]

Sferics near N France!

[Thunderstruck]

Cells popping up over other parts of Essex but nothing here yet. Still feels very ripe though.