29th November - 6th December 2011 Atlantic Storms

[Uncle_Barty]

Max temp here today was 13C. It appears that the only tea plantation in the UK on the Tregothnan Estate is extending it's season into Dec. for the first time. I love this cold spell.

The 1800z charts.

WS,

What is the link to those charts please?

[Isolated Frost]

WS,

What is the link to those charts please?

He generates them on his computer

[Liam J]

Very strong winds building ahead of the cold front during Tuesday morning, and just ahead of the front as it makes landfall on the mainland from Northern England southwards a small zone of very squally winds on a squall line before the winds veer westerly, the NAE shows this well on the 18z.

An interesting day of weather, well for the morning at least and it may be a very nasty and pretty dangerous rush hour for many places with very heavy rain, severe gales and squally damaging wind gusts.

Edited November 28, 2011 by Liam J

[Uncle_Barty]

Ohh.. ok!

[Jane Louise]

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.

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.

http://www.estofex.org/

[Zenarcher]

For the Saturday and Sunday storm the GFS 18z has given it another shift further North and this has once again downgraded the wind speeds. Most of Scotland will be looking at a gale force winds now perhaps reaching severe gale force over higher ground. Although Orkney and Shetland will still see severe gales and perhaps storm force.

As for next Monday although its still a week away the 18z has thrown out a powerful low that will pass over England.

Edited November 28, 2011 by weathermaster

[Upgrade]

looks like armageddon

[Roger J Smith]

The weekend storm potential is very dramatic looking on the 18z GFS.

Scotland gets the brunt of it on Saturday with possible gusts to 80 mph and temperatures low enough for heavy snow to fall just above sea level even in the west with mixed wintry showers at sea level.

Then the energy transfers to the southeast over the North Sea with severe gale to storm force winds indicated for large portions of eastern England from the northwest. If the 18z GFS maps verified you could expect gusts to 90 or 100 mph in exposed areas and potential damage even to buildings, not just loose objects and trees. It would also be cold enough for heavy snow to fall in some parts of northwest England and other exposed locations in Wales and Ireland, southwest England, although it would be more like cold rain showers or mixed wintry showers across the southeast. Temperatures would be about 4-5 C at best.

Too early to be sure on this scenario but if the intensity remains the same on the 00z runs, I would suggest that the thread be renamed to reflect the potential, something like

Severe Gales and Snow this weekend

might be appropriate, or just let this thread exhaust the potential for discussion of the weaker events on Wednesday and start a new thread dedicated to the Friday-Sunday time frame.

By the way, expect another severe windstorm if this pattern continues, around 9-12 December.

[syed2878]

Hey guys all this talks of storms in england and scottland what afect would it have for us in the midlands? Thanks.

[kold weather]

Well as I said in the model thread the system now between Sunday-Monday really is very impressive on the models, the GFS and the ECM both really go to town with it.

Long way to go yet though, and the pattern remains zonal and very active so plenty of storm threats to keep an eye on.

[Robbie Garrett]

looks like armageddon

I wonder if anybody is still moaning that the Models look boring, because what you've just said sums it up!!!

The weekend storm potential is very dramatic looking on the 18z GFS.

Scotland gets the brunt of it on Saturday with possible gusts to 80 mph and temperatures low enough for heavy snow to fall just above sea level even in the west with mixed wintry showers at sea level.

Then the energy transfers to the southeast over the North Sea with severe gale to storm force winds indicated for large portions of eastern England from the northwest. If the 18z GFS maps verified you could expect gusts to 90 or 100 mph in exposed areas and potential damage even to buildings, not just loose objects and trees. It would also be cold enough for heavy snow to fall in some parts of northwest England and other exposed locations in Wales and Ireland, southwest England, although it would be more like cold rain showers or mixed wintry showers across the southeast. Temperatures would be about 4-5 C at best.

Too early to be sure on this scenario but if the intensity remains the same on the 00z runs, I would suggest that the thread be renamed to reflect the potential, something like

Severe Gales and Snow this weekend

might be appropriate, or just let this thread exhaust the potential for discussion of the weaker events on Wednesday and start a new thread dedicated to the Friday-Sunday time frame.

By the way, expect another severe windstorm if this pattern continues, around 9-12 December.

I created that thread initially, but the two have been merged since I last looked for obvious reasons. No need for another thread.

Speaking of the above, does anyone remember that last time hundreds of trees where uprooted across London? Must have been at least 10 years ago, was at least 90mph gusts across London.

and for tomorrow, EGLL....TEMPO 2903/2910 19015G25KT BECMG 2910/2913 20018G32KT PROB40 TEMPO 2912/2916 SCT012 BKN020 BECMG 2916/2918 27016G26KT PROB40 TEMPO 2916/2918 25027G40KT 4000 +RA ......

Edited November 29, 2011 by Robbie Garrett

[Trugoy]

Unfortunatly I don't quite understand these weather charts yet but am i right in thinking the south east on England is in for a bit of a battering when this comes in??

[Robbie Garrett]

Unfortunatly I don't quite understand these weather charts yet but am i right in thinking the south east on England is in for a bit of a battering when this comes in??

Affirm, you're looking at widspread sustained windspeeds of 30-45knots with gusts up to 60knots in some places, at the moment mostly coastal areas, but if this beast goes further north as the recent model has shown, the densley populated Thames Region (i.e Oxford, London and Thames Estuary areas) could be in for a severe battering. What interests me is the jetsream is in a position I believe that is favourable to give the low a rapidly deepening affect (What's this called Netweather guys, I've forgot)??? but at the moment the English Channel then East of SE England is showing sustained winds of up to 70knots with gusts well into Hurricane force. One week to go though, before that comes to life - but I am not hoping for it as I live in the Thames Zone.

If the low rapidly deepens over Central England - your looking at 70mph sustained winds across London, but looking at the above model it shows the North Sea/low countries getting it!

Edited November 29, 2011 by Robbie Garrett

[Zenarcher]

Unfortunatly I don't quite understand these weather charts yet but am i right in thinking the south east on England is in for a bit of a battering when this comes in??

It's still a week away yet so things will change a lot between then and now but it is one to keep a watch on. But until we get closer to Monday (won't be until the weekend) until we will fully know.

Some say its the GFS over doing it I thought the same thing until I checked the other weather models and more less all of them were agreeing on it which is unusual at such a long range.

[AderynCoch]

Far from set in stone at this stage, but man the isobars are so thick you can't make out much of the Dutch-German coastline.

Say goodbye to Heligoland if this comes off:

Edited November 29, 2011 by AderynCoch

[Roger J Smith]

Actually, say hello to Heligoland if that comes off.

[weatherobsuk]

TORRO now have a Tornado Watch out in place for mostly all of the UK (except Northern Scotland) for today. http://www.torro.org.uk/site/forecast.php

[ZONE 51]

Here is a Map of the Gusts i expect through Tuesday

Edited November 29, 2011 by ElectricSnowStorm

[ZONE 51]

Charts below are the potential Storm for next sunday/monday-GFS - 18z.

its not often these show on such a southerly track, usually much further north

Edited November 29, 2011 by ElectricSnowStorm

[Aaron]

How's this for a storm?

[ZONE 51]

I would expect any track change would be more north then south, any downgrade would still hit as a potent gale i would think, i cant see a downgrade of significance happening to result in nothing, gales are likely, a storm could happen, and if this sweeps across southern England that would be rare, we dont see storms here very often.

Edited November 29, 2011 by ElectricSnowStorm

[Zenarcher]

Yes that's about the 4th time I've seen that storm chart posted now :lol: impressive one.

The GFS 00z has just rolled out and there is good new it's a massive downgrade. Personally from my experience because where I live I track storms all the time and they can change so much even within 6 hours. The downgrade is good news but still it could pop up again because I've seen it happen in the past.

[ZONE 51]

Late Sunday, surface pressure and jet stream! 140knot+jet!

Monday early,

The GFS 00z has just rolled out and there is good new it's a massive downgrade.

Just another run there, but yes good news its downgraded, need to see what other models do with it, quite amazing how things change, ive not looked at the 00z yet, i think with a week to go it would keep changing what is possible, wonder if it can upgrade some snow then!

[knocker]

Nothing too drastic on the inland shipping forecast this morning apart from the occasional F9 in the SW and W.

The midnight charts,

Edited November 29, 2011 by weather ship

[knocker]

Met rainfall forecast for 1300.