Potential Severe thunderstorm Thursday November 3rd

tylercollins · 02-11-2011 7:31pm #1

SKYWARN UK SEVERE THUNDERSTORM WARNING #059
ISSUED: 1530UTC WEDNESDAY 2ND NOVEMBER 2011

SKYWARN UK HAS ISSUED A SEVERE THUNDERSTORM WARNING FOR THE FOLLOWING REGIONS:
NORTHERN IRELAND
SOUTHWEST SCOTLAND
NORTHWEST ENGLAND
WALES
MIDLANDS
SOUTHWEST ENGLAND
SOUTHERN ENGLAND

IN EFFECT FROM 0000UTC UNTIL 2300UTC THURSDAY 3RD NOVEMBER 2011

UNSTABLE POST-FRONTAL ENVIRONMENT WITH LOW LEVEL CONVERGENT WARM AIR ADVECTION ENHANCING CONVECTION

SEVERE THUNDERSTORMS ARE EXPECTED, OR OCCURRING, SOMEWHERE WITHIN THE INDICATED REGIONS IN THE TIME PERIOD SPECIFIED. THREATS WITHIN THIS WATCH INCLUDE, BUT ARE NOT LIMITED TO:
HEAVY RAIN...HAIL...STRONG GUSTS...FUNNELS...TORNADOES...FLASH FLOODING...LIGHTNING

DISCUSSION:
THERE IS GOOD MODEL CONSENSUS OF A POSSIBLE SEVERE THUNDERSTORM EVENT WITHIN THE WATCH AREAS THROUGH THURSDAY. A COLD FRONT TRANSITS THE UK OVERNIGHT SLOWING OVER EASTERN ENGLAND, BEHIND WHICH 500MB TEMPS AS LOW AS -25C WILL ENCOURAGE WIDESPREAD CONVECTION MOSTLY INITIATING OVER SURROUNDING SEAS AND ADVECTING INLAND. LOW LEVEL WARM AIR IS ADVECTED UNDER A DEEP WIND PROFILE, WITH POSSIBLE SHORTWAVING AND RESULTANT CONVERGENT ZONES THROUGH THE IRISH SEA, IN LEE OF COASTS, PENINSULAS AND HIGH GROUND, AND THROUGH CENTRAL ENGLAND. 0-6KM DEEP LAYER SPEED SHEAR IS SUFFICIENT TO ENHANCE UPDRAFT STRENGTH AND HEIGHT, WITH EQUILIBRIUM LEVELS HIGHEST OVER NORTHERN IRELAND. LOW LEVEL DIRECTIONAL SHEAR IS SUPPORTIVE OF ORGANISED CONVECTION, WITH INCREASED POTENTIAL FOR FUNNELS, TORNADOES UP TO T2 AND STRONG CONVECTIVE GUSTING. PRECIPITABLE WATER IS UP TO 2.5CM SO CORES MAY BE HEAVY WITH POTENTIAL FOR FLASH FLOODING, ESPECIALLY FOR TRAINS OF STORMS. HAIL IS ALSO A CONCERN. THIS WARNING MAY BE UPDATED.

Iancar29 · 02-11-2011 7:48pm

* Hands Award for longest thread name in History! *

How come ME have nothing on this?

tylercollins · 02-11-2011 7:49pm

You don't have Martin "Funnel" McKenna as a friend :P that why haha

Does look promising tomorrow anyway for possible activity. Pity I'm god damn working

Iancar29 · 02-11-2011 7:55pm

tylercollins wrote: »

You don't have Martin "Funnel" McKenna as a friend :P that why haha

Does look promising tomorrow anyway for possible activity. Pity I'm god damn working

Hahaha!... Well if theres any word from MT or MÉ later then i might ask my mate to go on a ROAD trip so! ha

I really dunno where this "high" threat is coming from though for us , the instability is there yes but how is it gonna be fed?... it looks like it will be short lived storms .

Will wait for tonights models to come out around 9 to have another looksy.... going to walk le dog now.

vonbarracuda · 02-11-2011 7:56pm

http://met.ie/forecasts/warnings.asp

Sponge Bob · 02-11-2011 8:01pm

UKMO has the same warning but MUCH more chillaxed and less extensive, see.

http://www.metoffice.gov.uk/weather/uk/uk_forecast_warnings.html?day=1

Iancar29 · 02-11-2011 9:20pm

showforecast.cgi?lightningmap=yes&fcstfile=2011110406_201111022108_1_stormforecast.xml

I rather the oul Estofex forecast very much

Storm Forecast
Valid: Thu 03 Nov 2011 06:00 to Fri 04 Nov 2011 06:00 UTC
Issued: Wed 02 Nov 2011 21:08
Forecaster: GATZEN

A level 1 was issued for the British Isles and northern France mainly for large hail, severe wind gusts, and tornadoes.

A level 1 was issued for southern France and the west Mediterranean mainly for excessive rain.

A level 1 was issued for western and southern Iberia and surroundings mainly for severe wind gusts and tornadoes.

SYNOPSIS

The deep Atlantic long-wave trough will slowly enter Iberia during the period. A strong south to south-westerly flow will affect the British Isles, France, the western Mediterranean, and Iberia. The cold front will become mostly parallel to the jet and will be present from the western North Sea to France and the west Mediterranean at Friday morning. Rich low-level moisture is already present along the cold front and will even increase over the west Mediterranean given a moist south-easterly flow and strong low-level convergence. QG lift is likely from the British Isles to the west Mediterranean ahead of the eastward moving trough. This lift is expected to lead to increasing lapse rates that will overlap with the moisture.

DISCUSSION

British Isles, northern France

A tongue of very moist low-level air mass has spread into the British Isles and France and latest observations indicate surface dew points of 14°C. While the cold front crosses the Iberian Peninsula during the day, a frontal wave will be associated with backing surface winds from northern France to the British Isles in the afternoon and evening hours, associated with continuous moisture advection. Lift can be expected through-out the period given the approaching trough and mid-level jet streak as well as the frontal wave associated with warm air masses at low levels spreading northward. As a consequence, steepening lapse rates are forecast and CAPE becomes likely.

The overlap of the rich low-level moisture with strong low-level vertical wind shear (12 m/s 0-1km bulk shear) is clearly indicated by latest models. Main uncertainty will be the lapse rates and the chance of surfaced-based instability as well as the lift that may be rather weak. Current thinking is that showers and thunderstorms will develop rather isolated and will rapidly move northward. Some of these storms are expected to develop into supercells capable of producing large hail, tornadoes, and severe wind gusts. The convective activity will likely last until the night hours.

tylercollins · 02-11-2011 9:56pm

UKASF have just issued there forecast for tomorrow and friday..

http://ukasf.co.uk/storm-forecasts/139

They are going for sever in the south west of England and slight chance in Ireland.

Iancar29 · 02-11-2011 10:09pm

tylercollins wrote: »

UKASF have just issued there forecast for tomorrow and friday..

http://ukasf.co.uk/storm-forecasts/139

They are going for sever in the south west of England and slight chance in Ireland.

Awh no i hope this is not storms the seem to start only in the Irish sea and move East!

Hopefully now Met E. will have an updated forcast b4 the midnight staff take over.

tylercollins · 02-11-2011 10:14pm

the fun could be over before it even begins for us!

In saying that, I'm not going to see much as I'm working till 5pm from 8am

Iancar29 · 02-11-2011 10:22pm

tylercollins wrote: »

the fun could be over before it even begins for us!

In saying that, I'm not going to see much as I'm working till 5pm from 8am

Fingers Crossed so....

Ah sorry to hear that man... theres nothing worse! , like i was even thinking about asking for extra hours in work over the christmas then i was like... but ... what if the snow arrives again.... i cant be missing that! ha :rolleyes:

Tornando9 · 02-11-2011 10:33pm

As is the case with most of these setups nearly all the ingredients are there for a severe storm.
CAPE nearing 1000 j/kg and a lifted index of -2 or -3 so a nice buoyant airmass.
Lapse rates are excellent
Deep Layer shear is from 12-16 m/s Excellent for storm longevity as updraughts will seperate from the downdraughts.
Lower Layer shear is effin super 10-15 m/s so funnel development is favourable.
The one big massive letdown is a saturated atmosphere as humidity levels are very high through the 700hpa 500hpa and 300hpa with no real dry air intrusion.
Looks like a very Capped environment with the humidity creating an inversion but something could brew up and break through.

tylercollins · 02-11-2011 10:51pm

Torro have just issued a tornado watch as well for south western england the east coast of ireland and northern ireland.

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

tylercollins · 02-11-2011 10:53pm

Sponge Bob wrote: »

UKMO has the same warning but MUCH more chillaxed and less extensive, see.

http://www.metoffice.gov.uk/weather/uk/uk_forecast_warnings.html?day=1

They've updated there warning now with

2011-11-3

whiteandlight · 02-11-2011 11:29pm

Is this serious? We might actually get tornados???

km79 · 02-11-2011 11:36pm

Flying from
Dublin tomorrow

tylercollins · 02-11-2011 11:36pm

Yes, this is serious. High chance of something happening tomorrow. It's not going to be anything like you see on Storm Chasers or anything in the Great Plains, but something may happen.

P.S. We get more tornadoes here in the UK than America does lol

whiteandlight · 02-11-2011 11:38pm

tylercollins wrote: »

Yes, this is serious. High chance of something happening tomorrow. It's not going to be anything like you see on Storm Chasers or anything in the Great Plains, but something may happen.

P.S. We get more tornadoes here in the UK than America does lol

Seriously? That seems strange

Tornando9 · 02-11-2011 11:42pm

Musicmental85 wrote: »

Is this serious? We might actually get tornados???

Lots of things need to come together for a tornado to form but most of the parameters are there.
Just need a trigger for the convection now. There will be little or no insolation or diurnal heating as it'll be a cloudy day.
The trigger could come in the form of an upper trough which will create the lift required.
From experience setups like this usually fail to deliver here but pep up for the south and southwest of the UK.

Sponge Bob · 02-11-2011 11:43pm

OOPs they have and all. I'll get the washing out on the line tonight so.

Tornando9 · 02-11-2011 11:47pm

tylercollins wrote: »

Yes, this is serious. High chance of something happening tomorrow.

P.S. We get more tornadoes here in the UK than America does lol

This is not a serious situation i'm afraid and there is little chance of something happening.

We get on average about 9 or 10 tornadoes a year. Most are small and in the middle of nowhere.

In the USA they can have outbreaks of tornadoes that produce 100+ twisters in one day.

whiteandlight · 02-11-2011 11:49pm

Tornando9 wrote: »

Lots of things need to come together for a tornado to form but most of the parameters are there.
Just need a trigger for the convection now. There will be little or no insolation or diurnal heating as it'll be a cloudy day.
The trigger could come in the form of an upper trough which will create the lift required.
From experience setups like this usually fail to deliver here but pep up for the south and southwest of the UK.

Bear with me, I learnt a lot this year but not about tornados! What is insulation and diurnal heating?

tylercollins · 02-11-2011 11:51pm

Tornando9 wrote: »

This is not a serious situation i'm afraid and there is little chance of something happening.

We get on average about 9 or 10 tornadoes a year. Most are small and in the middle of nowhere.

In the USA they can have outbreaks of tornadoes that produce 100+ twisters in one day.

I think he was asking was this serious thread rather than a serious tornado outbreak.

And I should have explained that we get more tornadoes per square mile.

But here's to hoping for something to happen tomorrow because I can't get to America :P

Sponge Bob · 02-11-2011 11:51pm

Tornando9 wrote: »

Just need a trigger for the convection now. There will be little or no insolation or diurnal heating as it'll be a cloudy day.
The trigger could come in the form of an upper trough which will create the lift required.

Hang on a sec does that not mean LOTS OF SNOW AND EPIC BLIZZARDS IN DUBLIN AND WICKLOW as the unusual lift condition cools the moisture at high altitude?

Just askin like.

whiteandlight · 02-11-2011 11:55pm

I'm a she and yes I literally meant was this a joke! Assuming we don't get tornados is it just wet n windy we're looking at?

thetonynator · 02-11-2011 11:55pm

Sponge Bob wrote: »

Hang on a sec does that not mean LOTS OF SNOW AND EPIC BLIZZARDS IN DUBLIN AND WICKLOW as the unusual lift condition cools the moisture at high altitude?

Just askin like.

ahhh . . . . yeah :rolleyes:

Tornando9 · 02-11-2011 11:55pm

Musicmental85 wrote: »

Bear with me, I learnt a lot this year but not about tornados! What is insulation and diurnal heating?

This is when the sun heats the ground and the warm air rises. Warm air contains moisture so it condenses as it rises creating the lovely bubbly clouds or convection. If the convection is strong enough it keeps rising and when it hits the LFC (level of free convection) it rises even quicker creating an updraught.

TheMilkyPirate · 02-11-2011 11:56pm

Yay something interesting.

And i'm in a right spot for it aswell in the very far southeast corner of ireland in beautiful wexford

Sponge Bob · 02-11-2011 11:57pm

Tornando9 wrote: »

This is when the sun heats the ground and the warm air rises. Warm air contains moisture so it condenses as it rises creating the lovely bubbly clouds or convection. If the convection is strong enough it keeps rising and when it hits the LFC (level of free convection) it rises even quicker creating an updraught.

Exactly, except that it is cold at this altitude where moisture would not normally reach which must mean only one thing................................. SNOW!!!!!!!!!!!!!!!!!!!

Iancar29 · 03-11-2011 12:01am

tylercollins wrote: »

They've updated there warning now with

Thats more like it! , alot like the Estofex now too! ... only a good thing i guess !:)

Only thing to worry about now is LI 's ... or a A crappy squall line forming...

Tornando9 · 03-11-2011 12:02am

Sponge Bob wrote: »

Exactly, except that it is cold at this altitude where moisture would not normally reach which must mean only one thing................................. SNOW!!!!!!!!!!!!!!!!!!!

Yeah snow. Now put down the glue..

whiteandlight · 03-11-2011 12:03am

Got and with google i got it totally. Be an interesting day then. I foresee a December like thread refreshing on my part lol

Sponge Bob · 03-11-2011 12:04am

Tornando9 wrote: »

Yeah snow. Now put down the glue..

And sometimes when mosture ridden updraughts hit cold upper airflows you get GIANT HAILSTONES LIKE GOLFBALLS

(starts at 20 secs in ) This forum does not really do Giant Hailstones, they wanna hear snow or emmmm snow! :cool:

https://www.youtube.com/watch?v=wZr8jXo1Uso

Iancar29 · 03-11-2011 12:06am

Typical... i go away from my laptop for a bit and all hell breaks loose here! haha ... Calm down folks , no blizzards, no tornadoes ..... i m expecting some nice rumbles of thunder here and there maybe some nice structure too!

level 2 warnings from extofex even went to be a non event last time.

Mr Benevolent · 03-11-2011 12:08am

Meh, I'll believe it when I see it marching towards me.

wiger toods · 03-11-2011 12:08am

is the world ending again?

Sponge Bob · 03-11-2011 12:11am

wiger toods wrote: »

is the world ending again?

If you don't park your shiny new Beemer underground in the car park they just pumped dry...then possibly yes. :cool:

Iancar29 · 03-11-2011 12:12am

Confab wrote: »

Meh, I'll believe it when I see it marching towards me.

Your face 2moro evening...... :eek::eek::eek::eek::eek::eek::eek::eek::eek::eek::eek::eek::eek:!

Pangea · 03-11-2011 1:04am

tylercollins wrote: »

They've updated there warning now with

I wonder is West Donegal at risk too, (it might just be the met stopping the circle once the border ends)

M.T. Cranium · 03-11-2011 8:09am

I would say look out Wicklow and then Dublin (now to 1030h), incoming heavy showers may become thundery, torrential downpours and possible hail or gusty winds ... local flood potential should be monitored. A few places could see 20-30 mms in a two-three hour period. You know the drill.