Storm & Convective Discussion - 1 September 2015 onwards

[Mokidugway]

Due to tomorrow's forecast of naff all windshear and an alright chunk of CAPE, it's time for a davethedog convective forecast.

 

Storm Forecast

Valid: Tue 06 Oct 2015 06:00 to Wed 06 Oct 2015 06:00 UTC

Issued: Mon 05 Oct 2015 16:10

Forecaster: DAVETHEDOG

A HUMDINGER FREE ZONE was forecast for mainland Britain. Due to a sizeable chunk of CAPE floating above our cities and towns like an alien invasion if aliens were made out of slightly unstable airmasses, a few storms will pop up somewhere.

There's no cool stuff like wind shear floating around, so whilst the odd high street might become a massive puddle for a bit, we don't expect anything other than the odd flash punctuating an otherwise rainy autumn day, as Brits everywhere complain and sneeze into their Lemsips.

Winter is coming.

lol looking forward to your in depth drizzle forecasts this comming winter ..

[Spikecollie]

I haven't had a chance to look in detail, but the UK may get some of our French exports overnight. I'm on the borderline of the Estofex Level 2 over here. I'll...erm...let you know what's happening!

[Flash bang flash bang etc]

Due to tomorrow's forecast of naff all windshear and an alright chunk of CAPE, it's time for a davethedog convective forecast.

 

Storm Forecast

Valid: Tue 06 Oct 2015 06:00 to Wed 06 Oct 2015 06:00 UTC

Issued: Mon 05 Oct 2015 16:10

Forecaster: DAVETHEDOG

A HUMDINGER FREE ZONE was forecast for mainland Britain. Due to a sizeable chunk of CAPE floating above our cities and towns like an alien invasion if aliens were made out of slightly unstable airmasses, a few storms will pop up somewhere.

There's no cool stuff like wind shear floating around, so whilst the odd high street might become a massive puddle for a bit, we don't expect anything other than the odd flash punctuating an otherwise rainy autumn day, as Brits everywhere complain and sneeze into their Lemsips.

Winter is coming.

You should do one of these every day!

[William Grimsley]

I think showers hate me. They keep going straight to the east of here!

[dragon falls]

Big cluster of showers moving up from the south now couple of reds in there Wales Devon in the next hour or so.

[Liam J]

Quite intense areas of rain/showers heading into the SW. 

 

 

[dragon falls]

Wonder if any of the showers will any thunder in them over night in this area very muggy here 17

[Thunderbolt_]

There's a bit of light rain moving through here at the moment. What is interesting is there is someone letting off fireworks in the distance and it sounds like light rain with distant rolling thunder! It sounds wonderful

 

Hopefully it is ramping up for something tonight/tomorrow.

[Mokidugway]

Funny that been fireworks here too .

[IanR]

looked reasonable for the nw of england in earlier forcasts but things have changed as usual 

 

seems any thundery showers if they form tommorrow will be midlands, southwards, with the eastern parts of these areas a chance 

 

maybe some light drizzle here ,  all predictable stuff really 

Edited October 5, 2015 by IanR

[Nick F]

CONVECTIVE / STORM OUTLOOK TUESDAY 6TH OCTOBER

 

 

Issued: 05-10-2015

Valid: 06/10/2015 0000z to 07/10/2015 0000z

 

Synopsis

A long-wave upper trough sits close to the west of the UK with an upper ridge extending north across central Europe and Scandinavia to the east. A warm and moist S or SE flow cover the UK on Tuesday, with frontal systems moving NE. A cold front moving NE will become slow-moving across England and Wales, while a low over N Biscay moves NE to be centred over west English Channel by 12z Tuesday. Airmass will be slack and unstable across much of central and southern UK.

 

... ERN EIRE, WALES, ENGLAND and S SCOTLAND ...

 

Upper Vortex is visible on WV imagery Monday evening over N Biscay, with instability noted from CB clusters with lightning in the area. This area of instability invof upper vortex and associated surface low will move NE across Sern/central UK over the next 24 hrs. Cold mid-level temperatures associated with this upper low will steepen lapse rates from the SW Tuesday morning, which combined with forced ascent of warm/moist air by the approaching upper/sfc low and cold front, will support an increase in convection - with a risk of thunderstorms developing and spreading slowly north. 

 

The tendency will be for upper winds and deep layer shear to weaken as the upper low approaches and the jet stream pulls away east ... so organised storms with severe weather seem unlikely. However, slow movement of storms and training of cells over one area, particularly along cold front, could lead to excessive rainfall locally - leading to a risk of flooding. Additionally, low LCLs/cloud bases, very moist surface flow and local convergence, will increase the potential for funnel clouds or even brief/weak tornadoes or waterspouts to form with stronger updrafts - particularly across Wales, central and western areas of England. Storms may also be accompanied by hail and gusty winds

 

Issued by: Nick Finnis

Edited October 5, 2015 by Nick F

[Spikecollie]

I know I should be posting in the European storm forum - but allow me an indulgence. I'm seeing the flashes of every one of those strikes on Lightning Maps here in Limousin and it's so beautiful. It's like I have the only storm around!

Edited October 5, 2015 by Spikecollie

[Nick F]

I know I should be posting in the European storm forum - but allow me an indulgence. I'm seeing the flashes of every one of those strikes on Lightning Maps here in Limousin and it's so beautiful. It's like I have the only storm around!

 

We're not jealous    

 

Some nice Cb clusters and sferics over northern Bay of Biscay too though tonight and that area of instability has southern UK's name on it for Tuesday

Edited October 5, 2015 by Nick F

[Spikecollie]

We're not jealous    

 

Some nice Cb clusters and sferics over northern Bay of Biscay too though tonight and that area of instability has southern UK's name on it for Tuesday

I hope you get some storms! I'm going to bed happy but late, but suspect I might be woken by a few flashes and bangs to come. Night night...

 

LAST EDIT - woohoo that was closer than anything else! Very bright and white...

Edited October 5, 2015 by Spikecollie

[lassie23]

http://www.weatherweb.net/wxwebtv2.php

Edited October 6, 2015 by lassie23

[dragon falls]

Rain is lashing down no thunder yet radar looks like quite angry so dark here

[Gordon Webb]

Yep radar looks quite active looks like I'll have to leave cutting my trees to prepare for my christmas lights untill tomorrow surprised there is no thunder yet thank god it's not june or july or this would already be lighting up

Edited October 6, 2015 by Gordon Webb

[Azazel]

thunder heard here in Basingstoke

[Gordon Webb]

even though the rain is quite heavy in places thunder at the moment does seem rather limited

[Gordon Webb]

actually surprised that there's not more forum activity considering the forecast is it just the time of year now summer has passed and not much is expected now it's october , of course i generally disappear from this thread until april of the next year so perhaps it's not so surprising after all

[William Grimsley]

Heavy showers here last night but weirdly no thunder again!

[Gordon Webb]

loking at the radar there doesn't seem much of note behind this main band which have i assume is the cold front

[Gordon Webb]

Heavy showers here last night but weirdly no thunder again!

 

you've not really had much luck but looking at the radar there seems plenty of rain some heavy but not a lot of thunder

[Nouska]

A must see !!

 

https://vimeo.com/141374353

[Gordon Webb]

this is from the met office

 

Issued at:
1020 on Tue 6 Oct 2015

Valid from:
1230 on Tue 6 Oct 2015

Valid to:
2359 on Tue 6 Oct 2015
    

Although many areas will miss the heaviest rainfall today, some parts of the warning area are likely to see heavy, sometimes thundery and slow-moving showers, these leading to temporary surface water flooding in a few areas, together with minor disruption to travel.

    

A slack area of low pressure will move slowly across southern Britain today, bringing unstable air and the potential for thundery showers. The light winds mean that the downpours will be slow-moving as well as intense in some regions, with the possibility of 15 mm or more falling in less than an hour.

 

sorry William you don't appear to be included

 

think the met office is taking a precautionary measure so people don't get caught out and as for thunder that's in very short supply at the moment not that I have a complaint about that

Edited October 6, 2015 by Gordon Webb