Tuesday 6th Sept - Storms, high winds and rain

[Liam J]

Would this mean the stronger winds further north?

There are two main strong wind events, the first one overnight ahead of an active cold front sweeping east - this will give the west and south the strongest winds later tonight and into Tuesday morning, gusting 55-65mph potentailly.

The second swathe will affect more northern ares of Britian, Northern Ireland, Central Scotland, Northern England and North Wales - This is where the strongest winds will be during Tuesday Afternoon as the low move over N Scotland

Edited September 5, 2011 by james12

[lottiekent]

I recorded a 41.6mph gust here this afternoon

[Nick F]

Convective / Storm forecast - Issued 05/09/2011 22:30

Forecast Summary Map

Valid: 06/09/2011 00:00 - 07/09/2011 06:00

Headline: ... THERE IS A SLIGHT RISK OF SEVERE WEATHER FORECAST...

Synopsis

Short wave trough currently to W of Scotland on the crest of a strong Atlantic jet streak will move east across Nern UK during Tuesday. unseasonably deep depression near Western Isles at 12z in the left exit of this jet stream will move east across Scotland, while active cold front sweeps SE across Eire then Wales and England during Tues morning clearing the SE early afternoon.

… SLGT RISK FOR ENGLAND, WALES TUES AM …

Active cold front surges SE across Eire then Wales and England during Tuesday morning ... a narrow band of modest instability is indicated along this front as it passes through - so line convection is likely along/ahead of this front, as tongue of warm moist air from the SW ahead of front is forced to rise. Lightning activity maybe limited due to fairly shallow convection, though favourable kinematics from model output suggest convection may organise to bring a threat of severe weather.

Given the SEward movement of the front against the SW'erly low-level flow, very strong low-level shear (up to 45-50 knts) is indicated across England and Wales during the morning, this combined with suggested drier air intruding at 700mb and rather low LCLs near front ... indicates the risk of one or two tornadoes developing - if sufficient low-level bouyancy of warm moist airmass can develop ahead of front.

In addition, there will be a risk of strong damaging convective gusts of up to 60knts as a result of very strong upper winds lowering through dry air incursion as mentioned.

Risk will subside as cold front clears SE England early afternoon,

… EIRE, SCOTLAND and NW ENGLAND TUES PM …

Post cold front rPm airmass will move in here - characterised by steepening lapse rates from the NW as colder air aloft spreads SE above moist surface flow ... which will support heavy showers and isolated to scattered thunderstorms across these areas in the afternoon/evening.

Issued by: Nick F - Forecaster for Netweather

[coldfingers]

Just begun to get very gusty indeed here in the last 15 minutes. Wind now risen again to F7 gusting F8 and it is likely to get much worse during the night.

[Purplepixii]

Not much happening here BUT what's that just west of Ireland!!!!circle!!

sat24

I too noticed that circle on the western edge of Ireland - what on earth is it (if anything)??

Took a screen grab before it disappears off the radar...

[coldfingers]

I too noticed that circle on the western edge of Ireland - what on earth is it (if anything)??

Took a screen grab before it disappears off the radar...

I would put my money on a fault on the radar.

[Aaron]

I saw the circle too, on Raintoday, both radars can't be playing can they lol

[Raidan]

Nothing happening here,We had some rain this afternoon and a bit of a breeze but nothing out of the ordinary,Hoping some thundery stuff comes along but not looking likely grrrr.

[loopydreamer]

still early for the south east but have just noticed the wind getting gusty in the last 20 mins or so

[<<Ryan>>]

That same circle also appeared on Netweather radar

Edited September 5, 2011 by 0ryan0

[Liam J]

My take on the current developments out west atm

[Chris K]

I saw the circle too, on Raintoday, both radars can't be playing can they lol

That same circle also appeared on Netweather radar

Definately the tell-tale signs of a fault with radar equipment of some sort. That circular feature only appeared on the radar for that one 'tick'. It showed the rain moving in as normal afterwards, in a less unusual fashion.

[loopydreamer]

flippin eck we just had a big gust here in chatham! that had to be the biggest gust today! probably not quite but it felt like a 40 to me! i was outside just having a fag! i get sooo excited and hyper in very windy weather! shame it has the potential to cause damage and injury to folks! rather puts a dampner on it!

[ZONE 51]

The wind charts are interesting, just been through the layers, the interactions across England during tuesday morning and afternoon are amazing!

the jet streak pulsing in at 120knots! through Ireland,Wales and England, the same time we have the cold front what would become a severe squall if the elements meet at the right time,

jet stream above-look at the yellow zone

then the gales blowing changing direction from sw to nw along with the cold front also sucking in some moist air flow from the sw,

look at the dew points here, first one is morning then midday,

dew points above,

the ppn charts show the downpours up strong with the deep blues, NAE charts below..

-

the tornado risk is certainly there and coming along with a gale its quite a concern, not only the tndo risk but squall convective gusts increasing the wind general gusts up to damaging levels

-

if i got anything wrong please say!

been reading throught the day just off to read back in the thread now..oh and Backtrack that last risk box is excellent and pretty much shows the potential!

Edited September 5, 2011 by ElectricSnowStorm

[coldfingers]

flippin eck we just had a big gust here in chatham! that had to be the biggest gust today! probably not quite but it felt like a 40 to me! i was outside just having a fag! i get sooo excited and hyper in very windy weather! shame it has the potential to cause damage and injury to folks! rather puts a dampner on it!

I know exactly how you feel there. It is a love/hate relationship. Love the power of the gusty winds/hate the damage or injuries that may be caused.

Then i think, there is nothing I can do to stop it, so I enjoy it while I can.

[Backtrack]

The circle is just a slight glitch. Since all radar data is provided by the Met Office from all of the radars posted, it's an error in one of the updates.

[Raidan]

Im i right in guessing not much is likely to happen in SW England? Haven't had any rain for hours now and there is hardly any wind.

[Aaron]

Wind starting to pick up here, none of the heavy rain forecast though.

[weatherobsuk]

The beginnings of s possible squall line now forming across central Ireland, going to be a long night to wait before it crosses into Wales and England so off to hit the bed for some 'Z's for a few hours before daybreak.

[ZONE 51]

latest radar-both same but line drawn on first image to show squall line and thundery developments possible over the SW moving across England.

http://www.metoffice.gov.uk/

[ZONE 51]

Ive bolded the headline! and a part of the text below.

-

TORRO TORNADO WATCH 2011/007

A TORNDAO WATCH has been issued at 22:40GMT on Monday September 5 2011

Valid from/until: 22:40 - 17:00GMT on Monday September 5/Tuesday September 6 2011, for the following regions of the United Kingdom & Eire:

Parts of (see map)

Eire

N Ireland

England

Wales

S Scotland

THREATS

Tornadoes; wind gusts to 65mph; occasional CG lightning

SYNOPSIS

Upper low will approach NW Scotland through the period, slowing and deepening as it does so. At the surface, a well-marked cold front will move aross the British Isles, with strong warm advection just ahead of it. Strong 500 hpa height falls /up to 10-11DAM in 12 hours/ will overspread the cold front, promoting lift. Despite very moist profiles, some steepening of lapse rates is likely aloft, especially as the front splits and drier air overspreads the moist zone ahead of the surface front, increasing potential instability.

As the upper low slows, the front will also tend to slow somewhat as the mean tropospheric flow backs. This will serve to increase low-level convergence along the front, especially as it moves across England and Wales later tonight and through Tuesday. Indications are that a LEWP type structure may develop. Strong low-level wind shear /0-1km shear of >30 knots/ and low LCLs, combined with -ve LIs at 700 hPa and up to 150J/Kg of CAPE suggests that tornadoes are possible. Whilst the overall risk seems rather widespread, an enhanced risk, perhaps with several tornadoes, appears likely to extend from Wales, into the Midlands and E Anglia, along with parts of Cent S and SE England late tonight and through Tuesday.

Much of the LEWP activity may be low-topped, with little lightning present. However, there may be a higher chance of lightning across parts of Wales and N England for a time, and it cannot be ruled out elsewhere.

Forecaster: RPK

http://www.torro.org...te/forecast.php - TORRO

Edited September 6, 2011 by ElectricSnowStorm

[ZONE 51]

rapidly developed over the last hour

2am

3am

[Sprites]

16.3c+ temps at the moment in the south west and and south east, ex-hurricane fuel perhaps.

[Dorsetbred]

Is it me or has the radar lost it's sync again?

Seems each time we have some interesting weather the radar go belly up or slows down, currently an hour behind real-time.

[Liam J]

I'm surprised the Meto didn't issue any warnings, look at the intensity of the rainfall that has crossed/crossing the uk.