Uk General Convective Discussion & Forecasts, 10th October 2012>

[Tom Quintavalle]

Hi Coast,

Looks like this weather type for the next few days, with parts of Sussex/Kent, especially the coastal fringes, prone to heavy and perhaps thundery showers at times.

We see this type of weather quite a lot during the Autumn period when the flow is conducive to sparking off some convection over the still relatively warm Channel.

Regards,

Tom.

Edited November 2, 2012 by TomSE20

[Coast]

Looks like this weather type for the next few days, with parts of Sussex/Kent, especially the coastal fringes, prone to heavy and perhaps thundery showers at times.

Hi Tom,

it does look like there area few chances coming up, mainly to the West I think but also around here:

[Raidan]

Very dark sky now and a nice big rainbow,oh how I wish this would go BANG.

[Ben Sainsbury]

I have been in Woolacombe for the past week and not been on lately but luckily have the chance to report 3 torrential showers yesterday, all with hail and one with thunder. 2 showers during the night with hail and another shower with hail this morning. What a cracking time here.

I have been in Woolacombe for the past week and not been on lately but luckily have the chance to report 3 torrential showers yesterday, all with hail and one with thunder. 2 showers during the night with hail and another shower with hail this morning. What a cracking time here.

[Ben Sainsbury]

Yet another 2 heavy hail showers on the way back from Woolacombe. No thunder heard.

[Liam J]

Had a spectacular hail shower earlier, no thunder just intense hail which brought traffic to a standstill along with very strong winds.

[ZONE 51]

Recent lightning radar shows where all the action is tonight

in the Channel and one lightning strike over south Wales..

The chart above that i posted has changed from what it was when i posted it, didn't know posted images update like that?

[Aaron]

Bit old, but didn't see any mention of it on here..

Weather News

Tornado in southwest Dublin area in the early hours of October 17th

01 November 2012

A tornado has been confirmed in southwest Dublin area in the early hours of October 17th. At approximately 6am, a tornado travelling in a south-north direction, travelled a mile or more from the Crumlin area towards the Phoenix Park. It caused damage in the order of trees uprooted and damage to local homes. Currently Met Éireann is consulting with tornado research scientist John Tyrrell about this event. Further information will be available in the future after data analysis and a full investigation have taken place.

Met Éireann

Edited November 3, 2012 by Aaron

[Raidan]

Morning all,currently on a train to Brighton and was wondering if anyone could give me a idea of what the weather forecast is for there or if anything convective is forecast,cheers

[Snowysand]

Here in littlehampton just heard a loud rumble of thunder from the sea so I guess in the channel there is something

Morning all,currently on a train to Brighton and was wondering if anyone could give me a idea of what the weather forecast is for there or if anything convective is forecast,cheers

[flysurfer]

Thunder in the channel off dover

[Coast]

Thunder in the channel off dover

It's really been scooting up The Channel this week and there's more to come.

Storm Forecast

Valid: Sat 03 Nov 2012 06:00 to Sun 04 Nov 2012 06:00 UTC

Issued: Fri 02 Nov 2012 18:17

Forecaster: TUSCHY

SYNOPSIS

An extensive cyclonic vortex over N-Europe steers numerous disturbances over most of Europe, which are embedded in a brisk W/SW-erly flow. Weak ridging continues over SE Europe with less shower activity affecting those regions. With a significant negative anomaly of the blocking index present throughout the forecast period, no major pattern change is expected for the time-frame of interest.

Again, isolated to scattered thunderstorms are forecast beneath the cold core vortex, where either forcing, mid-level temperatures or regionally enhanced SSTs favor deep and electrified convection over offshore areas of NW Europe. Beside a few strong wind gust events with that convection, the overall activity remains sub-severe.

I'm liking the 21st OWS map for today which is probably spot on:

Surface CAPE is all around us:

Mid level CAPE is no more than the last few days but the potential for another day of action through The Channel can be seen here:

Of course more rain is on the way today here, substantial amounts overnight into tomorrow:

Lapse rates again are strong:

A slight chance of more thunder today:

and maybe tomorrow:

[Liam J]

Some impressive clouds developing and producing hail, very ominous looking skies.

[Nick F]

Valid: 03/11/2012 12:00 - 04/11/2012 12:00

Headline: ... THERE IS A RISK OF THUNDERSTORMS FORECAST...

Synopsis

Large vortex/low pressure system covers UK and Ireland, characterised by a cold core, with mid-level temperatures below -30C. Predominately W/SW'erly flow will be unstable - particularly where cold airmass contrasts with warm seas around the UK.

... S and W COASTAL AREAS OF IRELAND, ENGLAND, WALES AND SCOTLAND ...

Cold rPm airmass across the UK, characterised by steep lapse rates, will be most unstable over relatively warmer sea surface temperatures (SSTs) - which will favour deep convection. Heavy showers and a few thunderstorms over seas surronding the UK and Ireland will move onshore at times through the day over western and southern coastal areas exposed to the wind. There is a risk of hail and strong wind gusts with any showers/storms, along with isolated lightning.

Overnight, a low is indicated to develop in the SW approaches ahead of a shortwave trough swinging east on the southern flank of the vortex. This low will bring an area of convectively enhanced precipitation to southern England in the early hours of Sunday, with a risk of a few embedded thunderstorms - which could bring a threat of localised flash-flooding. Also, given strong jet winds aloft and veering winds with the passage of the low, strong vertical shear brings a low risk of a tornado and there is also a risk of isolated strong damaging wind gusts with any convective downbursts.

Also can be found here: http://www.netweather.tv/index.cgi?action=convective;sess=

Issued by: Nick F - Forecaster for Netweather

[Erbyskerby]

Lovely little thunder storm at the mo - scooting past us on its way up the Bristol Channel. Quite a bit of thunder and lightning out to sea. Heavy hail at times - hoorah!

[Kain]

Just had a hell of a hail storm here, 10 - 15mm hail stones and it went icey cold! Brilliant!

[Coast]

Sferics out in The Channel and NW ATD shows a big blob of them coming this way, yes please!

[philglossop]

1 flash and a bang during a big hailstorm in Stonehouse, Plymouth at around 1805hrs. Most unexpected, but welcomed!!

Quick edit- showing nicely on the rain today radar for 1800hrs. The hail was bad as it forced the smokers back into the pub!

Edited November 3, 2012 by philglossop

[Nick F]

Line of storms/sferics from IOW up through Hants and Wilts on recent Atd update, presumably cold front or triple point area of meso low tracking NE over the SE this morning.

[Coast]

Thunder in Eastbourne!

No forecast from ESTOFEX this morning so a quick round up of other sources from me for the day:

SkyWarn:

SKYWARN UK SEVERE WEATHER WATCH #062

ISSUED: 2000UTC SATURDAY 3RD NOVEMBER 2012 (GJ/GS)

SKYWARN UK HAS ISSUED A SEVERE WEATHER WATCH FOR THE FOLLOWING REGIONS:

SOUTHERN ENGLAND SOUTHEAST ENGLAND EAST ANGLIA ISLE OF WIGHT CHANNEL ISLANDS

IN EFFECT FROM 0000UTC UNTIL 1500UTC SUNDAY 4TH NOVEMBER

DEVELOPING LOW WITH STRONG CONVECTION AND GALES

THERE IS A POSSIBILITY OF SEVERE WEATHER AFFECTING THE INDICATED REGIONS IN THE TIME PERIOD SPECIFIED. THREATS WITHIN THIS WATCH INCLUDE, BUT ARE NOT LIMITED TO:

HEAVY RAIN...FLASH FLOODING...GALES...STRONG GUSTS...HAIL

DISCUSSION:

THERE IS BETTER MODEL CONFIDENCE OF THE POSSIBILITY OF A SEVERE WEATHER RISK THROUGH SUNDAY. A WAVE DEVELOPS UNDER THE EDGE OF THE JET INTO A TIGHT LOW PRESSURE SYSTEM AS IT CROSSES THE CHANNEL. THIS FEATURE SHOULD BE STRONGLY CONVECTIVE FOR THE EARLY PART OF THE PERIOD, BRINGING CHANCES OF HEAVY RAIN AND HAIL INTO COASTAL AND NEIGHBOURING AREAS ANYWHERE EAST OF HAMPSHIRE. MORE PRESISTENT AND OCCASIONALLY HEAVY RAIN MAY BE EXPECTED AS FAR NORTH AS CAMBRIDGESHIRE AND EASTWARDS. FOLLOWING THE HEAVY RAIN THERE WILL BE WINDS OF POSSIBLY ABOVE 50MPH FOR COASTAL AND EXPOSED LOCATIONS, PERHAPS WITH WINDS GUSTING IN EXCESS OF 70MPH. THIS WATCH MAY BE UPDATED OR UPGRADED. PLEASE MONITOR WEATHER AND TRAVEL INFO AS NECESSARY.

21st OWS spot on!

Plenty of shear along The Channel:

Vorticity:

and of course, rain

Surface CAPE up again with a disturbance along the South coast:

Odd low-level lapse rates:

But stronger further up:

Tornado possibility for my area mid day:

and still those gusty winds

Maybe a chance for more thunder into the darker hours????

[Andy Bown]

My Dad said he was woken by thunder in Westbury at 7.20 this morning, heard nothing 5 miles away.

[Coast]

Hmmm, ESTOFEX have this out for today:

Storm Forecast

Valid: Mon 05 Nov 2012 06:00 to Tue 06 Nov 2012 06:00 UTC

Issued: Sun 04 Nov 2012 23:54

Forecaster: SCHLENCZEK

A level 1 is issued along the coastal regions of the Adriatic Sea for excessive convective precipitation, severe wind gusts and tornadoes.

SYNOPSIS / DISCUSSION

A baroclinic zone is found along a line from N Morocco via the Balearic Islands towards E Czech and Poland. The associated cold front separates warm and moist air over the Mediterranean from cool polar air over W Europe. At the northeastern tip of the frontal zone, cyclogenesis is expected during Monday, leading to a low pressure system with a minimum SFC pressure around 980 hPa forecast for Tuesday evening. Deep moist convection is not expected with this low pressure system, but isolated severe wind gusts may occur due to the gradient flow.

In the wake of the cold front, some low-end instability is forecast over parts of France and Benelux during the late morning and afternoon hours. Due to very low LCL heights and weak background winds, a slight chance of spout-type tornadoes will exist.

I can't really see it worrying us too much:

Simple format GFS says way out in The Channel:

or off the East coast:

[A.J]

Relatives down in Brixham have reported a decent thunderstorm there in the past couple of hours with hail & wet snow....Certainly looked quite lively down there first thing just off the South Devon coast....Looks like most of the convective activity is moving off the coastline SE into the English Channel

[Coast]

BBC radio weather forecast this morning made specific mention of possible thunder in Scotland today. I've had a quick look and I just can't see that currently? GFS just shows rain up there?

[Ben Sainsbury]

Any risks of any heavy showers/storms today. I do see an anvil to my southwest which is fairly close though radar shows nothing under 40 mile away?