244 replies to this topic

[Jane Louise]

Bugganuts, on 05 August 2011 - 20:43 , said:

Cheers and you to But ye its changed a couple of times for me over the past day or two! A few hours ago it had the 'light shower' symbol over me but then it changed back to thunder... We will just have to see how things develop on the day

One thiing I did wonder, the fact its a lot cooler - will that hinder the potential convective activity a lot? (I know temps arent the only factor) but daytime surface heating does help development right? I'm no expert in these things

Hmmm., correct me if I 'm wrong anyone! But I think cloud cover, lack of solar heating and a few other things are all signs that can prevent any convective activity. Cool air though, I am not sure of. I'm still learning too lol

If you haven't already seen it then here is an interesting article that Nick F wrote.

http://forum.netweat...erstorm-setups/

[Jane Louise]

Estofex latest forecast.

SYNOPSIS

Upstream of a broad ridge over eastern Europe, a trough moves into western Europe. A trough/vorticity maximum initially located to the southwest of Ireland is expected across the southern North Sea on Sunday morning.

http://www.estofex.org/

[Staffordshire]

BBC don't seem to be making much of Sunday

[Mesoscale]

Oh look Scotland is going to be getting the storms again...

Good luck you guys!

[ElectricSnowStorm]

An interesting period coming up for the next few days with Thunderstorms for many areas at some point from North to South!

il leave the DATA for the early posters! so are be reading and wondering when and what where and if!




-


On a Serious note the very heavy rain saturday could cause big flooding problems and into sunday so this is a concern.

Edited by ElectricSnowStorm, 06 August 2011 - 03:42 .

[SNOW_JOKE]

Is it me or do these convective events recently have a nack for sneaking up on us at the last minute. Maybe it's just me being proccupied with events over in the Caribbean concerning ex-TS Emily. But we went from weds/thur's events and the charts wasn't showing anything significant until next weekend. Now GFS has today as a main contender for thundery rain & possible serious flooding concerns.
I see its a SSL developing out over Cumbria and Southern Scotland, but just its development in terms of model projection from +72hr out is somewhat disconcerning.

[Harry]

I've maintained it always that you're more likely to see something when you're not expecting, rather than when you're sitting staring at a radar/satellite hoping for things to.

Things are starting to kick off up north earlier than I expected - some really quite rapid convection occurring and some really quite heavy rain so early in the day.

[Coast]

Jane Louise, on 05 August 2011 - 21:10 , said:

Estofex latest forecast.

SYNOPSIS

Upstream of a broad ridge over eastern Europe, a trough moves into western Europe. A trough/vorticity maximum initially located to the southwest of Ireland is expected across the southern North Sea on Sunday morning.

As good a place to start as any! Morning all.



UKASF:

Quote

Forecaster: Dan
Last Updated: 18:58 Friday, 5th August 2011
Valid: 00:00 Saturday, 6th August 2011 - 23:59 Saturday, 6th August 2011

MDT: S + E Ireland
SLGT: N + E England, Borders, Ireland, Northern Ireland, Wales, SW England, West Country
Synopsis:

A large, elongated, vertically-stacked and multi-centred upper low becomes established across the British Isles on Saturday. Convection will be widespread, with a few thunderstorms expected.
Discussion:

Beneath the upper low, lowering geopotential heights and a cold pool will overspread the country, with T500's as low as -25C, steepening lapse rates. Diurnal heating will aid convection development, with as much as ~600 J/kg CAPE available. Consequently, showers will become widespread across Ireland and western Britain, and with ELT's as low as -30C over Ireland, thunder and lightning is likely in quite a few showers.

DLS of up to 50kts is forecast over Wales and W England during the day, which is likely to help organise the convection. However, relatively weaker DLS (less than 20kts) is likely across Ireland, and this will slowly spread eastwards into Wales by evening. Meagre LLS will preclude a tornado risk. Given the cold mid levels, small hail is likely in some of the showers, particularly over Ireland. Concern exists that excessive cloud cover may inhibit convection, particularly over Ireland. Strong steering winds will mean any showers that do develop will move fairly quickly, but much lighter upper level winds over Ireland, particularly the W, will allow slow-moving showers and local thunderstorms to exist. Showers that do develop will continue well into the evening, becoming mostly confined to coastal parts where the risk of lightning continues to exist.

A developing trough feature is also forecast to move northwards across England, into southern Scotland during the forecast period. Whilst high precipitation totals are likely over the Borders/NE England, the lack of any other severe conditions prevent us from issuing a SVR threat level. There are indications that there may be an increase in convection along this feature during the afternoon and early evening, but ELT's of only -20C and excessive cloud cover, combined with lower surface temperatures, are likely to mean that lightning, if any, will be quite isolated in nature.

I think the highlighted text in the forecast above is the headline for today

TORRO and SkyWarn have no current alerts or watches





21st OWS MetO interpretation shows something in the approaches:



That may be with us overnight:



Interesting to see what the aviation weather from WAFC Washington shows in the Atlantic:



WAFC London has a whole heap of stuff on its way - is it just rain?



The KO index taken on its own would be keeping me radar watching at the end of the afternoon:



But other ingredients are just not there;



A little bit of CAPE for Northern Ireland shortly:



Then nothing all day except for a tad in the North East and some creeping into RoI later:









Convective rain in RoI and the NE:







So it looks like Southern Ireland may have a slim chance followed by a slimmer chance to the NE and Scotland but don't hold your breath! I'll have a look what the next couple of days potential is looking like on the general thread.

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[SNOW_JOKE]

Cheers Coast. Things starting to crank up here with some heavy rainfall and big raindrops giving the village a rude awakening this morning, radar shows for some more development coming within the hour yet still and just the start of whats to be an expected active 24 hours.

[Dommy]

Got woken up by a torrential downpour, I am really surprised that there was no thunder, it was that heavy.

[Dazmaster75]

Just absolutely chucked it down here, most of it has gone east of my location, not heard any thunder from it though.

May have just heard a distant rumble.

Edited by Dazmaster75, 06 August 2011 - 08:57 .

[Chris K]

A beefy clump of showers looks like they are heading their way in towards the SW. Nothing electrical detected within it though yet, but it looks like pretty heavy rain as it approaches Cornwall/Devon.

[CreweCold]

Dazmaster75, on 06 August 2011 - 08:55 , said:

Just absolutely chucked it down here, most of it has gone east of my location, not heard any thunder from it though.

May have just heard a distant rumble.

Heavy rain and lightning in Stockport area recently, looking on the radar it's nice to see the usual suspects collecting their daily downpours.............not. Pretty much given up on expecting a storm here now in summer 2011. Not one has been registered throughout June, July and up until now, I believe.

[Paul-Michael]

Pouring down here now, no lightning or thunder but very heavy all the same, not been raining that long and there's already huge puddles everywhere, in fact it could b mistaken for winter! lol

[Paul-Michael]

Literally torrential now and has been for the last 10 mins flash flooding all over this is unreal. Thunderstorm rain without the storm!

[I Cumbria Marra I]

take a video/picture

[Staffordshire]

Got awoken at 5:15 by a torrential downpoar!

[Paul-Michael]

I Cumbria Marra I, on 06 August 2011 - 09:30 , said:

take a video/picture

What of a council estate with flooded pavements and burst drains etc lol In all probability the drainage system here isn't the best which isn't helping I don't have the facility where I am this morning, seriously though rain was unreal for a time the type you get when you have a storm and it just floods everywhere, it has just started to die back to heavy now but utterly miserable day tbh wouldn't mind if there were flashes of lightning and thunder!! Forecasts are saying thunder etc but I doubt I will hear some here !

[Cloud 10]

Plenty of strikes showing up west of york at the moment,could be some action for cumbria as well.

Edited by Cloud 10, 06 August 2011 - 09:48 .

[gpspete]

not lightning watching but tonight there may be a good chance of a seeing the AURORA cloud permitting as there is a major geomagnetic storm hitting earth at the moment its a class G2+ and is expected to ramp up to a class G3+

Geomagnetic Storm Effects



G2 (Moderate)

Power systems: high-latitude power systems may experience voltage alarms, long-duration storms may cause transformer damage.

Spacecraft operations: corrective actions to orientation may be required by ground control; possible changes in drag affect orbit predictions.

Other systems: HF radio propagation can fade at higher latitudes, and aurora has been seen as low as New York and Idaho (typically 55° geomagnetic lat.).

G3 (Strong)

Power systems: voltage corrections may be required, false alarms triggered on some
protection devices.

Spacecraft operations: surface charging may occur on satellite components, drag may
increase on low-Earth-orbit satellites, and corrections may be needed for orientation
problems.

Other systems: intermittent satellite navigation and low-frequency radio navigation problems may occur, HF radio may be intermittent, and aurora has been seen as low as Illinois and Oregon (typically 50° geomagnetic lat.).

onto todays non geomagnetic storms
Latest from my lightning detector

Edited by gpspete, 06 August 2011 - 10:08 .