Convective / Storm Discussion - 28th July onwards 2013

[I Cumbria Marra I]

As expected, it starts to die once it hits cumbria, NEXT.

[wimblettben]

Plenty of heavy showers today but no thunder. Suprising really considering all of these lightning reports we've had around this area.

 

Tomorrows my last chance now, if I don't get anything tomorrow then it looks like I'll be waiting for a long time.

[Nick F]

Valid: 29/07/2013 0000z to 30/07/2013 0000z
Headline: .... THERE IS A RISK OF THUNDERSTORMS FORECAST ...

Synopsis
Cyclonic southwesterly flow at all levels covers the UK on Monday ahead of vertically-stacked long-wave trough and surface low pressure system close to the W of the UK, bringing another convectively active day across many parts of the UK.

UK AND IRELAND

Widespread convective activity is likely again on Monday ... as cold mid to upper level air of upper trough overspreads from the west atop of warm and moist martime surface flow - creating steep lapse rates and unhindered deep convection with help of daytime insolation, though convection maybe already ongoing to start the day. Deep layer winds will be generally unidirectional - so 0-6km vertical shear will be rather weak, which will mean storms will tend to be scattered rather than organised. However, despite weak vertical shear, CAPE is expected to be quite abundant (600-1000j/kg CAPE forecast), so storms will be capable of producing high rainfall totals with risk of flash-flooding, along with isolated hail of up to 2-3cm in diameter. Though given the scattered rather than organised nature of storms, will not issue a categorical severe risk for now, though some areas may see a succession of storms while other places have just one or escape them altogether. Storms will tend to be more slow-moving across northern mainland UK and N Ireland, so here will likely see the greatest risk of flash-flooding.
 

Issued by: Nick Finnis

 

[I Cumbria Marra I]

Electricity just went off for a second, haven't heard any rumbles though just heavyish rain

[slb97]

Had about a dozen fork lightning and thunder not directly overhead but great nonetheless

[nitro_deluxe]

Any sign of that cape in sunny Cumbria

Electricity just went off for a second, haven't heard any rumbles though just heavyish rain

[Adi F]

Can confirm a storm has just passed over Chichester with a couple of flashes of lightning. Next door can confirm it too as I sprinted to the car and ran straight into her knocking her over.

[nitro_deluxe]

Plenty of heavy showers today but no thunder. Suprising really considering all of these lightning reports we've had around this area. Tomorrows my last chance now, if I don't get anything tomorrow then it looks like I'll be waiting for a long time.

Week end next?

[Carl46Wrexham]

Seems I picked the wrong week to go to Minehead, Somerset.

 

Absolutely nothing there in the way of activity this past 7 days. Gutted.

[Derbyshire_snow]

One I shot earlier as thundery showers tease me

Got a photo of that from top of Ringinglow Rd 

[*Stormforce~beka*]

You what there is thunders? I have only had rain - biiiiiiig rain

[Carl46Wrexham]

Woo hoo nice thunderstorm over Wrexham atm. Only saw one flash of lightning but heard about 12 good rumbles of thunder, including one that shook the windows lol. Finally I've got a storm, shame I didn't see more lightning but can't have it all lol

Took a nice shot of a double rainbow at the beginning of the storm :-)

image.jpg

 

Pleased for you....Gutted for me.....didn't get back to Wrexham until 40 minutes ago.

[wimblettben]

Week end next?

That thundery plume is only suppose to affect southeastern areas not here in Wiltshire.

[ZONE 51]

 

Fewer/weaker showers are expected across SE England due to the short land track. - ukasf.

 

Looks like are just have to wait for the end of the weeks MCS for the SE then.

Edited July 28, 2013 by ElectricSnowStorm

[ZONE 51]

-

Edited July 28, 2013 by ElectricSnowStorm

[Swave Snow]

We've got a rather heavy shower taking place TORRENTIAL and Tropical

[Allseasons-Si]

Well,i have just played back all the clips(6 of them) of this afternoons storm and didn't catch a single lightning strike,just rumbles,so i won't be uploading them

 

the trouble was,it was too far away or the rain sheet obscured them from this point of view,nevermind,hope for a better one soon

 

the trouble is though,i am on afters this week,but hope to catch a night time shot.

[Swave Snow]

We've got a rather heavy shower taking place TORRENTIAL and Tropical

 

Slowed down to nothing now

[SarahWxm]

Pleased for you....Gutted for me.....didn't get back to Wrexham until 40 minutes ago.

Oh no, I'd be gutted! It wasn't the greatest storm ever but some good cracks of thunder (1 in particular overhead made me jump a mile!). There was some great cloud formations too. Hoping we get another one soon in this storm starved part of the country lol

[Robbie Garrett]

Intense rainfall here, no thunder & lightning. Squall line it seems

[ZONE 51]

(18Z data)

For Monday's storm potential just to post a few charts to admire.

 

GFS - 500hpa - very cold:

 

Total cloud cover 1800hrs:

 

Some clear skies indicated along the south coast. The white areas are total cloud the greys are more broken cloud, this could mean that storms are why there is the cloud at 1800hrs for example.

The sunny breaks earlier allowing surface to heat up.

 

Dew points 1500hrs:

 

GFS showing 15-16C dew points for some areas.

 

Surface pressure is quite low:

Surface temperature:

 

20-23C generally (poss 24C)

 

Next upper temperatures at 850hpa:

 

Cooling layer.

Now the precipitation charts, first the 6hr then 12hr:

0600-1200hrs , quite a lot of activity indicated for western and northern areas early in the day.

 

0600-1800hrs, this shows widespread ppn activity across most areas for Monday(heavy showers and thunderstorms), the drier area being the SE.

I'd expect that areas west and north of London would get some big downpours or storms. We can now take a look at NAE's ppn see what the model shows to GFS.

 

NAE.

0900-1500hrs ppn:

Only EA/SE not much about showing on these up to 3pm.

But it shows the north/west/east and central areas getting a lot of ppn(showers/storms)

The last chart is 1200-1800hrs looks like the SE might not get much looking at GFS/NAE.

Edited July 28, 2013 by ElectricSnowStorm

[Allseasons-Si]

I see there is quiet a bit of ppn starting to develope in the midlands,i will be keeping an eye on these over the next couple of  hours before i turn in.

Edited July 28, 2013 by allseasons-si

[PiggiePalace]

Hi - newbie just joined. Love this site!

 

All quiet in the Mid Sussex microclimate - aka 2 miles south of East Grinstead - despite being bang in the squall line according to current radar.

 

This area was wiped out by flash flooding from the local stream on 20th July 2007 at approx 11.15am following 55mm of rainfall falling in 45 minutes bewteen 9.30 and 10.15am.

 

Given current conditions ref parched ground/weather, we have had the flood defences up since last week expecting the worst - but apart from about 2 hours of heavy but not torrential rain, including one lightning flash and a couple of rumbles, on friday afternoon....we've had absolutely nothing else! Our last flood alert was Xmas Eve last year...and I can;t rememebr our last rainfall!For those of you waiting expectantly - I'm very happy to redirect anything your way!xxx

[nitro_deluxe]

I see there is quiet a bit of ppn starting to develope in the midlands,i will be keeping an eye on these over the next couple of  hours before i turn in.

Several bands of showers in fact, pushing right down and across into parts of Wales - moderate rain nil sparks as yet, more rain for one still quite parched garden? Despite near on 40mm since Friday pm.Quite humid feel, winds light, Summer 2013 rumbles on into week five of relative warm, albeit now wetter weather. Outlook not too bad either for quite a few.

[Snowshine]

Looks like I might be able to catch a thunderstorm tommorow!

With a CAPE of just over 800j/kg, an LI of -3 and 64% max humidity, it looks like thunderstorms are capable tommorow.

Can someone tell me the wind shear for tommorow? West Midlands.