Storm & Convective Discussion - 1 September 2015 onwards

[Costa Del Fal]

Wasn't it always gonna be like that?

When I looked the other day I'm sure there was a risk for us in the south west.

[Nick F]

CONVECTIVE / STORM OUTLOOK MONDAY 14TH SEPTEMBER

 

 

Valid: 14/09/2015 0000z to 15/09/2015 0000z

 

Synopsis

A sharpening upper trough, very distinct on water vapour imagery, continues to dig SE across western France this evening, before lifting NE across southern Britain overnight and through Monday. A strong jet stream will wrap around this upper trough sliding east across NW Europe though its influence will be well removed from the UK to south across France. A surface low will drift slowly NE across SW England, Midlands on Monday before exiting N Sea Tuesday morning. An unstable rPm airmass moves NE across England and Wales during the forecast period.

 

... WALES, S ENGLAND, MIDLANDS, YORKS, LINCS and E ANGLIA ...

 

Increasingly cold and dry mid-upper flow spreading east and NE around upper trough across the Bay of Biscay and western France atop of moist maritime surface airmass is creating a pool of steep lapse rates and several 100 j/kg CAPE. This pool of unstable rPm air, characterised by steep lapse rates, will also spread NE across much of England and Wales over the next 24 hrs. So expect an increase and strengthening of convection across S England/S Wales overnight as drier air aloft/steep lapse rates overspreads from the SW, with a risk of scattered thunderstorms tracking NE. Already there are some sferics in the western English Channel Sunday evening. 

 

Insolation will perhaps further enhance coverage of thunderstorms during daylight hours on Monday across England and Wales away from the far north of England. Although 0-6km / deep layer shear will be weak, which will limit storm organisation, showers/storms will be slow-moving and tending to form lines moving NE, so bringing a risk of localised flooding in places, have issued a MARGINAL risk for flooding.

 

Backing of surface winds or surface convergence ahead or near low moving slowly NE may enhance low-level shear, which combined with light winds aloft, brings the potential for brief/weak tornadoes or waterspouts. Storms maybe also be accompanied by hail and frequent cloud-to-ground lightning. 

 

Issued by: Nick Finnis

[Allseasons-Si]

met office have warnings out now 

 

For Monday 

 

 

http://www.metoffice.gov.uk/public/weather/warnings/#?tab=warnings&regionName=se&fcTime=1442185200

 

 

Hi Maxum

 

i have opened a new thread on this subject,best placed there, as this is the storm/convective thread  

 

https://forum.netweather.tv/topic/84005-atlantic-storms-autumn-2015/

[Thunderbolt_]

Yes as mentioned in the previous posts, we could see a few thunderstorms moving up from the South Coast this afternoon. However, I expect these to be very hit and miss (even more than usual) to be honest. Many of the parameters for storm forecasting look very marginal to me, meaning that some could see a pretty beefy storm, and others could see nothing at all. Of course it will also depend on where the clouds break later on...

 

This mornings NetWx run for 15:00:

 

[NO LONGER POSTING]

Thing with today is that it's a shame the parameters don't all fall into place at one time otherwise storms would be more organised and widespread.. Some gaps in the cloud showing now over the channel which should aid things 

[Nick F]

Rumble of thunder from a cell just to the NW of herre near Croydon. Some nice convective cloudscapes gleaming in the sun this morning.

[BB1979]

Thunder in Central London? Sounded like it but in the office so hard to tell

[Methuselah]

A tasty-looking anvil a few miles south of here...

[Nick F]

Rather pulse-type these thundery showers, showing what little shear there is. Short but intense bursts of rain.

[Gordon Webb]

this thread is surprisingly quiet today would have expected more but then again the thunder activity does seem to be in short supply perhaps that's why

[MP-R]

The only thing missing from here this morning was thunder, other than that I've had:

1) without doubt the heaviest rain so far this year with an incredible noise on the roof that sounded more like hail and caused the lights to flicker

2) very gusty winds that sent the rain across in sheets

3) daytime darkness

4) now partially flooded roads

 

If there was thunder, I didn't hear it.

[East_England_Stormchaser91]

Awesome little storm just passed through here currently giving some cracking peels of low booming thunder.

Sun coming out now.

Edited September 14, 2015 by East_England_Stormchaser91

[ChezWeather]

Fairly active storm near Leicester 

[Paul]

Just taking the chance to show off the new 500 metre radar - it really picks up the detail in the showers today!

 

[Nick F]

Tornado in Northampton earlier this afternoon ... Quite clearly see the rotating tube:

http://www.northamptonchron.co.uk/news/local/video-tornado-caught-on-camera-sweeping-across-northampton-1-6956370

Edited September 14, 2015 by Nick F

[Allseasons-Si]

Fairly active storm near Leicester 

 

Just wondering if they make it up here,camera @ the ready

 

Tornado in Northampton earlier this afternoon ... Quite clearly see the rotating tube:

http://www.northamptonchron.co.uk/news/local/video-tornado-caught-on-camera-sweeping-across-northampton-1-6956370

 

that's a pretty awsome clip that,it's a shame there was no more footage,although i probabley would of done a runner too

latest,looking like it could be a direct hit here with the Leicester storm and the Lincolnshire storm joining forces

Edited September 14, 2015 by Allseasons-si

[A.J]

more footage of the Northamton tornado courtesy of MetWeatherUK

 

 

https://video-lhr3-1.xx.fbcdn.net/hvideo-xpt1/v/t42.1790-2/12017304_10207537486733089_165080465_n.mp4?efg=eyJybHIiOjMwMCwicmxhIjo1MTJ9&rl=300&vabr=165&oh=3068ed35dbac035466f0a368b1ce6a0b&oe=55F6E612

 

 

a bit of a convective bust here in Wilts, just one moderate shower earlier...a very poor year to date in this neck of the woods

[Gordon Webb]

behind that line of showers moving north through the midlands which stretches into lincolnshire the showers don't seem as intense , I'm sure there is a simple reason or not be could someone enlighten me

[Greeny]

Cloud bases were very low today always a plus for tornado potential and always worth keeping a lookout on days like today. We've had some nice cloudscapes today and some decent pockets of rainfall. Clearing up a bit now with sunny spells.

[Flash bang flash bang etc]

So absolutely no convective action for the Central South today. Bit of a misfire for the forecasts - but I understand it was always a volatile situation.

Just wonder why it's so hard to get some lightning in our area. Heavy rain, yes! Lightning, nO neVer!

[Winter Cold]

Its more like a November day here, thick fog up here all day and no sign of any sun, convection or wind at all. Strange really as there are some heavy showers pushing north not to far away!

 

The radar does show the intensity dropping like a stone though on that clump heading for Sheffield. Im not surprised really as its not the conditions for storms here!

[East_England_Stormchaser91]

Turning out to be a cracking day for cloudscapes.

Can hear the thunder booming out of the cell to my west!

[Mokidugway]

Sky's increasingly threatening here ..

[Winter Cold]

I must be on a different planet

 

[East_England_Stormchaser91]

I must be on a different planet

 

IMG_20150914_152549.jpg

Jeez!! What a contrast 70-80 miles makes or even less than that!

Explosive conditions in south lincs at the moment with towers rapidly shooting up all over. Heading your way too!!