29th November - 6th December 2011 Atlantic Storms

[Coast]

Quite a defined line running down the Irish Sea today with plenty of rain to the East of it into Western Britain

[Liam J]

Very windy here, the wind is picking up quite significantly from the south atm. Gusting 55-60mph.

[sparky1972]

not that windy here at the mo.

[Coast]

Latest from SkyWarn:

SKYWARN UK SEVERE WEATHER WATCH #063

ISSUED: 1730UTC MONDAY 28TH NOVEMBER 2011 (GJ/SM)

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

IN EFFECT FROM 0300UTC UNTIL 2359UTC TUESDAY 29TH NOVEMBER 2011

ACTIVE COLD FRONT WITHIN AN UNSTABLE ENVIRONMENT

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...STRONG GUSTS...FRONTAL VORTICES...T1/2 TORNADOES...FLASH FLOODING

DISCUSSION:

THERE IS MODERATE MODEL CONFIDENCE IN THE POTENTIAL FOR A SEVERE WEATHER EVENT DURING TUESDAY. A COLD FRONT CROSSES THE ENTIRE UK EASTWARD FROM EARLY MORNING, AFFECTING MOST PARTS DURING THE AFTERNOON. UNDER THE LEADING EDGE OF A STRONG JETSTREAM WITH A SLACK WIND FLOW BEHIND, THE PRE-FRONTAL ENVIRONMENT IS EXPECTED TO GUST TO 50KTS WITH POTENTIAL FOR CONVECTIVE ELEMENTS WITHIN. THE FRONT APPEARS TO BE SPLIT, WITH THE UPPER SECTION COOLING THE MID LEVELS OVER THE SURFACE FRONT, GIVING RISE TO POTENTIAL INSTABILITY BOTH AHEAD AND BEHIND. A STRONG SHEAR PROFILE IS SUPPORTIVE OF VORTICES WITHIN THE FRONT, AS WELL AS POSSIBLE TORNADOES. OVERALL PRECIPITATION ACCUMULATIONS ACROSS SCOTLAND AND NORTHERN ENGLAND COULD WELL EXCEED 60MM FOR THE PERIOD, PARTICULARLY STEEP SLOPES AND SHARP CATCHMENT AREAS. THIS WATCH MAY BE UPDATED OR UPGRADED.

[Aaron]

Severe Warning issued by estofex too

http://www.estofex.org/

[Coast]

+ a level 1 from ESOTFEX for the UK:

Storm Forecast

Valid: Tue 29 Nov 2011 06:00 to Wed 30 Nov 2011 06:00 UTC

Issued: Mon 28 Nov 2011 21:48

Forecaster: KOROSEC

A level 1 was issued for parts of UK mainly for strong to severe wind gusts and tornadoes.

A level 1 was issued for southern Mediterranean sea mainly for strong wind gusts and excessive convective rainfall.

SYNOPSIS

A ridge/high pressure area dominates Europe while very intense confluent trough remains in place over NE Atlantic. At surface, a deep SFC cyclone slowly translating across the Norwegian sea with a strong cold front extending southwards towards the UK. Another focus for Tuesday's convective activity will be a decaying upper low, moving from Tunisia into southern Mediterranean.

DISCUSSION

... parts of UK ...

As the deep cyclone near Iceland moves further NE across the Norwegian sea, an associated strong cold front will be pushed across the British Isles. This setup is characterized by very strong jet streak, providing impressive vertical wind shear at all levels. Despite very limited instability signals on numerical models, strongly forced convection is becoming likely along the trailing cold front. The front will cross the level 1 area during the afternoon and early evening hours. As said, very strong shear will be in place, with above 30 m/s of deep layer shear and 20-25 m/s of LL shear, combined with strong 300-500 m^2/s^2 SR helicity. Expect a likelihood of a well-organized convective line with embedded mesocyclones along the cold front itself. Those storms should support severe wind gusts and possibly tornadoes as well, given the robust shear in place. A polar maritime airmass will overspread the area further north and support widespread low-topped convection.

Persisting strong SW flow will result in excessive amount of rainfall over coastal SW Norway.

Severe Warning issued by estofex too

http://www.estofex.org/

SNAP!!!

[Liam J]

Deteriorating rapidly here, very heavy driving rain, poor visibility and southerly gales.

[Coast]

Amber warning out for some parts of Scotland, with the SW, Ireland and Wales also included in the watch zone:

http://www.metoffice...t_warnings.html

[knocker]

The active cold front is over Ireland at 0600z. I suspect the rainfall may be more of a problem than the wind.

[Liam J]

I expect the winds to peak between now and 12pm over the N & W as the cold front moves ever closer.

[Coast]

Latest readout from buoy 62094 in the Celtic Sea roughly half way between Ireland and Wales

[Liam J]

After a brief lull the winds will pick up again this evening with westerly gales for a time over parts of the NW. Looking at the 6z further gales or severe gales during Wednesday evening over Scotland, N Ireland and N England, 50-55mph winds in the N Irish sea and 55-60mph winds over Western Scotland.

Edited November 29, 2011 by Liam J

[weatherobsuk]

Highest gusts on xcweather as of 10:40am

Capel Curig 74mph

Aberdaron 68mph

Valley 61mph

Scilly Isles 60mph

St Bees Head 58mph

[TornadoJo]

http://www.torro.org.uk/site/forecast.php

[Jimmyh]

Guys surely on the last pages showing 964mb that is close to the great storm of 87 some serious damage would be caused if this did come off.

[Lauren]

Oh i love a bit of extreme weather. The current models (that i understand - not many!) look like it will be a beast.

My rain guage always blows over in strong winds though

Are we looking at hurricane force winds?

[Liam J]

Oh i love a bit of extreme weather. The current models (that i understand - not many!) look like it will be a beast.

My rain guage always blows over in strong winds though

Are we looking at hurricane force winds?

Hi Lauren, are you referring to the storm for the weekend and early next week? No there will not be hurricane force winds, people don't half get get carried away sometimes! It will be very windy that's for sure, but at this stage anything could change regarding the storm as we have some time to go before we reach the weekend and early next week. Still some uncertainty in the short term with the exact details and track of any depressions which may affect the UK, exciting times for storm enthusiasts!!

Still very windy here on the Cumbrian Coast, gusting up to 60mph with a few gusts in excess of this.

Edited November 29, 2011 by Liam J

[Lauren]

Hi Lauren, are you referring to the storm for the weekend and early next week? No there will not be hurricane force winds, people don't half get get carried away sometimes! It will be very windy that's for sure, but at this stage anything could change regarding the storm as we have some time to go before we reach the weekend and early next week. Still some uncertainty in the short term with the exact details and track of any depressions which may affect the UK, exciting times for storm enthusiasts!!

Yes, i was. i have seen hurricane force winds referred to in this thread so was asking if this is actually the case.

i hope the models stay as they are I love a good storm (as long as everybody is safe!).

[knocker]

Latest rainfall and gusts for 12 and 1300.

[Coast]

Better pop this in here too, from TORRO:

TORRO TORNADO WATCH 2011/009

A TORNADO WATCH has been issued at 09:50GMT on Tuesday November 29 2011

Valid from/until: 09:50 - 20:00GMT on Tuesday November 29 2011, for the following regions of the United Kingdom & Eire:

Parts of (see map) Eastern Eire Eastern N Ireland England Wales S Scotland IoM Channel Is

THREATS

Tornadoes; wind gusts to 65-70mph

SYNOPSIS

A strong, well-marked cold front will surge eastwards today as a pronounced upper trough moves eastwards across the British Isles. Line convection has already been noted across Eire/N Ireland and S Scotland this morning, and as the front accelerates eastwards, this will cross the WATCH area. Low-level shear just ahead of the front will be strong /35-50 knots/ - this will probably allow misocyclone/LEWP development along the line convection, locally enhancing SREH (which will already be high), and increasing the risk of strong winds. In addition, small but non-zero CAPE and neutrally buoyant or marginally unstable air in the lowest 3km may enhance the tornado risk. This seems most likely where air comes in from the warmer seas (e.g. S England) - however, there is the suggestion that slightly -ve 700 hPa LIs may extend into the Midlands and E Anglia too. Although the risk area is large, the higher probabilities seem to be for Wales, and England south of a Liverpool - Hull line.

[Lauren]

I think if this comes to life we should refer to it as 'The Beast'.

[Robbie Garrett]

I think if this comes to life we should refer to it as 'The Beast'.

Ooooh I wanted to call Next weeks storm 'Lauren'

[Lauren]

Ooooh I wanted to call Next weeks storm 'Lauren'

I only want to lend my name to the biggest and best storm so ner.

[Coast]

I think if this comes to life we should refer to it as 'The Beast'.

We've done the beast too many times. I think it should be called Storm Lauren too.....

[Lauren]

Oh Ok you've convinced me. But only if it comes into fruition.

This means it's going to be a damp squib now doesn't it, then i shan't be happy

You've got the brunette bit right, sadly my boobies are not as large....

Edited November 29, 2011 by Lauren