Storm & Convective Discussion 12z 21/7/14 ------>

[poseidon]

Supacell, on 01 Aug 2014 - 06:29, said:Supacell, on 01 Aug 2014 - 06:29, said:

The BBC were talking about thunderstorms being imported from France into the SE and EA during the early hours of tomorrow. GFS doesn't appear to support this with little in the way of CAPE or precipitation forecast although lapse rates do increase towards tomorrow morning to the SE and E of London. NMM does show around 500j/kg of MLCAPE moving up from the south into that same SE corner towards morning and then tomorrow both models develop some decent CAPE and lapse rates across all of the SE and EA for Saturday. Neither GFS or NMM show heavy precipitation but the Euro 4 does for the early hours (although this is still on it's 18z run as I type this).

 

From this morning's runs I think it is worth highlighting the possibilities of a brief plume of thunderstorms from the continent affecting the likes of Kent, Sussex, Essex early tomorrow and then Suffolk and eventually Norfolk through tomorrow morning/afternoon. If BBC are correct then we need to bring this all about a few hours earlier, which would be good for some more night time lightning across the likes of Kent/Essex/Sussex once more.

I noticed this little feature moving up over Kent on NMM that has appeared intermittently on several runs recently...

 

 

ECMWF also shows a blob of rain moving over SE early morning. Will it be thundery though.

What time does the MLCAPE move in?

Edited August 1, 2014 by poseidon

[Harry]

August is traditionally the best month for storms in Norfolk - it better live up to that tradition as we were poorly served by the last "event"!

 

Same here...over the years August has been awesome, although in recent years July tending to deliver the goods.

 

As its 1st August and the next day or so is showing some promise, lets hope it continues

[Flash bang flash bang etc]

I haven't had one single thunderstorm in August yet, hopefully this will change tonight :-P

[ThunderBuddy21]

So the charts are showing that the worst of the possible stroms from the continent are going to clip kent and the bbc are showing them going over where I am, which to I believe? Or is it a case of waiting and seeing but they are going to be somewhere in the south east?

Some forecasts are showing us geting a soaking tonight and others are showing no rain at all

Edited August 1, 2014 by ThunderBuddy21

[TonyH]

I haven't had one single thunderstorm in August yet, hopefully this will change tonight :-P

Give it chance the months not 12 hours old yet

[johnholmes]

I haven't had one single thunderstorm in August yet, hopefully this will change tonight :-P

 

said a poster 10 hours into the 1st day of the month-grief, some folk!

[Paul]

said a poster 10 hours into the 1st day of the month-grief, some folk!

 

I'm sure it was a sarcastic comment John

[Greeny]

I did notice this 2 hours earlier but looking at the very near future, potential over east anglia especially over norfolk and Suffolk is showing in the nmm latest run.

It could be lost to the sea though so I think its touch and go. Dry air aloft punching in from the south west is not as dry as in the previous run.

Unlike the front or trough whatever it is heading from the west side of the country.

Edited August 1, 2014 by Greenday

[Biggin]

I think it was a joke.Anyways BBC have rain for SE about 3 am so will have a look at radar this evening.

[Greeny]

Models do show higher theta-e values coming up from France during the night.

Oh yes and this little lot..

Edited August 1, 2014 by Greenday

[Utahraptor]

Here's some footage of a storm I got yesterday, the closest strike came within about 500-600m

 

https://www.youtube.com/watch?v=27aMyjIp6kM

[Greeny]

Oh yes and this little lot :-)

[poseidon]

Met Office seem to be firming up the forecast now for the East overnight....

 

"Although some parts may start the night dry, outbreaks of rain will affect most places overnight, some of which will be heavy and thundery. "

[Greeny]

Here's some footage of a storm I got yesterday, the closest strike came within about 500-600m

Nice footage. Nice low front moving in there. Yesterday's brief storm at about 6.30 had an unexpectedly strong gust front to your average storm even though there was no cloud definition of one. It was eary as it got close and when it did hit I did run for cover lol. I got some footage after the first gust hit trying to capture cloud motion. Not sure if it is that easy to see though. A couple of flashes and rumbles but it was mainly north of me.Videos are in the timeline below..https://m.facebook.com/home.php?soft=side-area#!/groups/1407218326228566?view=info&ref=bookmark Edited August 1, 2014 by Greenday

[Nick F]

Storm & Convective Forecast

 

 

Issued 2014-08-01 13:22:59

Valid: 01/08/2014 1200z to 02/08/2014 1200z

 

THERE IS A RISK OF THUNDERSTORMS FORECAST

 

Synopsis

Long-wave upper trough and surface low pressure close to the W and NW of the UK will drive a cyclonic SWly flow across the UK, an occluded frontal zone will lie SW to NE across the UK, lying Torquay-Birmingham-Whitby at 18z, moving very slowly E, a new developing area of low pressure will move into the SW approaches this evening, with a thundery trough moving N out of France across SE England later this evening.

 

… SW ENGLAND, E WALES, MIDLANDS, N and E ENGLAND …

 

Cyclonic SWly flow across the UK and slow moving occluded front lying diagonally across England and Wales, will provide large scale ascent of fairly moist Tm airmass advecting NE. Widespread cloudiness and dynamic rainfall across W Wales and N England may limit convective potential here, however breaks in the cloud/sunshine across the northern most counties of SW England, E Wales, Midlands, E/NE England will help increase CAPE in moist airmass, with GFS indicating 300-700 j/kg 15-18z across these areas … which will support development of scattered thunderstorms. Upper SWly will be sufficiently strong for storms to organise into line segments or multicell clusters, capable of producing strong wind gusts, marginally large hail (1-2cm) and torrential rainfall leading to flash flooding.

 

... SE ENGLAND and E ANGLIA FROM 21Z …

 

Models indicate a shortwave trough moving N out of France this evening, which may bring multicell storms or perhaps an MCS across SE England and E Anglia overnight, these storms maybe capable of producing strong wind gusts, hail, frequent cloud-to-ground lightning and torrential rainfall leading to localised flooding.

 

… EIRE/N IRELAND and W SCOTLAND …

 

Unstable airmass and surface heating with any cloud breaks will support scattered convection with heavy showers and isolated thunderstorms this afternoon, some of which may produce localised flooding.

 

Issued by: Nick Finnis

Edited August 1, 2014 by Nick F

[Harry]

Multicells? Or potential MCS???? Oh Nick I like the sound of that...I know its by no means (in any way shape or form) guaranteed, but my excitement levels have bumped up ever so slightly.

 

Just out of interest the Sun has been out now for a good few hours and its very warm (and increasingly humid feeling) too.

[Weather-history]

Rain has been showery in nature with heavier bursts.

Brightened up with sun breaking through.

[A.J]

Multicells? Or potential MCS???? Oh Nick I like the sound of that...I know its by no means (in any way shape or form) guaranteed, but my excitement levels have bumped up ever so slightly.

 

Just out of interest the Sun has been out now for a good few hours and its very warm (and increasingly humid feeling) too.

I had a sneaky feeling that you'd like his forecast H!...

 

good luck to those in the south east!

 

For me in central southern england, well sort of in no-mans land with chances of convective rainfall (possibly thundery) tonight to my west and a possible MCS to my east.....hmm, will still watch the radar with interest as you never know! 

[Biggin]

 

 

Just out of interest the Sun has been out now for a good few hours and its very warm (and increasingly humid feeling) too.

 Can confirm humidity increase here.

[legritter]

I had a sneaky feeling that you'd like his forecast H!...

 

good luck to those in the south east!

 

For me in central southern england, well sort of in no-mans land with chances of convective rainfall (possibly thundery) tonight to my west and a possible MCS to my east.....hmm, will still watch the radar with interest as you never know! 

yes very true [as you never know ]absolutely pouring down here in north somerset ,although i have been watching the radar the intensity of the rain for the last 25 mins totally caught me out ,interesting period coming up .certainly a radar watching period and certainly i think forecasts will be updated by the hour .we certainly make up for dry periods these days ,probably no different than past history but seems that way .cast your minds back to spring and some were saying we dont get the storms we did years ago ,well wait and you will be rewarded .i think that whats make Meteorology so interesting .computer seems to be playing up so apologes if posted this wrong ,cheers 

Edited August 1, 2014 by legritter

[Raidan]

Finally some proper rain its needed.

As for thunderstorms I think it will be along time before I see another one.

Can't really complain as had 4 in one day in July but I still want more.

Seems the SE will be hogging them as usual.

[ThunderBuddy21]

Finally some proper rain its needed.As for thunderstorms I think it will be along time before I see another one.Can't really complain as had 4 in one day in July but I still want more.Seems the SE will be hogging them as usual.

Feel free to come and take them !! Lol

[Harry]

Finally some proper rain its needed.As for thunderstorms I think it will be along time before I see another one.Can't really complain as had 4 in one day in July but I still want more.Seems the SE will be hogging them as usual.

 

Hold your horses there, we haven't hogged storms for many a year...this is probably the first year in several I could say with any shred of confidence we are up there in the regional league table...the last few years has been the glory times of the Midlands and NE England in particular (and of course Lincs/Cambs region)

 

This year has turned out a better than average year thus far, but that's only because July was so generous. Up to the first week of July (ish) my storm statistics for the whole of 2014 was 2 thunder days (2 thunder events), and only one of them (around late May I think) was of any real cop, on a scale of 1-10 for excitement and severity I'd score it a 4/10 - the other was a couple of thundery bits. July however, particularly from mid July onwards, a dismal year has transformed into a memorable one.

 

Tonight is by no means guaranteed either, with my gut feeling pushing any notable activity eastwards towards C/E Kent, Essex and maybe E Suffolk/E Norfolk. Quite possible we'll have some heavy rain, but as often happens in these sorts of set-ups the electrical activity is higher on the eastern flank of storms.

 

We shall see how it all unfolds...but nevertheless well excited about some nowcasting and radar/lightning detector watching.

[lassie23]

London has been pretty quiet storm wise over recent years, Lincolnshire has become the thunderstorm capital of England!

[Lauren]

Totally agree Harry, we have been long overdue storms.

 

It seems for the SE, storms are like buses.