Atlantic Storms 13th to 16th December 2011 - Part 4

[knocker]

The 0600 Atlantic and UK charts.

[Liam J]

Morning

Well, another shift southwards on the 00z runs perhaps?

GFS also still likes the idea of snowfall later over the Midlands and Southern England, also a trough feature running through Northern parts of England overnight.

For anyone who hasn't read through it yet, Netweather have issued an alert in advance of the storm.

Potential for gales, heavy rain and snow across southern Britain Thursday night into Friday morning

Issued on 14/12/2011 at 18:37

Valid From: 14/12/2011 at 18:00 until 16/12/2011 at 18:00

Regions affected:

Areas affected in detail:

Wales, The Midlands, southern England and East Anglia

Severity level:

Weather type:

Gales, Heavy Rain and Snow

Alert risk period:

15/12/11 18:00 until 16/12/11 18:00

Alert details:

This is an alert for potential severe weather across southern Britain later on Thursday and into Friday morning.

The low pressure system which has been forecast to move close by to or over the UK during late Thursday and Friday is currently forecast to track very close to the south coast of England, meaning the strongest winds are likely to affect France rather than Britain. Southern coastal counties may buck this trend though with gusts of 50-70mph possible here through the night on Thursday.

Heavy rain will also accompany the low pressure system, bringing local falls of 25-40mm in southern counties and 10-25mm likely in parts of Wales the Midlands and East Anglia. As cold air undercuts the rain through the night on Thursday, it is expected to fall increasingly as snow through the Midlands and Wales with high ground most at risk but even lower lying areas liable to see falling and potentially even settling snow. 5-15cm are likely to fall on higher ground, with a few cm's possible at those lower levels.

Ice will also be a hazard particularly as the rain, sleet and snow clears through later in the night.

It's important to note that although we are now at a fairly close range, there is still some uncertainty with regard to the track of this low pressure system - a slight change in track further north could well result in winds of 60-80mph or higher affecting southern counties and possibly East Anglia. Also this would take the rain, sleet and snow further north. A more southerly track will mean the rain, sleet and snow becoming more confined to southern regions.

We'll continue to update this alert during the upcoming 24 hours.

Confidence: 60%

Issued by NJF for Netweather.tv

Edited December 15, 2011 by Liam J

[Coast]

Morning all!

More exciting and nail biting times ahead. Lets start with the convective potential for today and I have already seen lightning this morning out in the Channel. Here's what the usual sites say about today:

ESTOFEX

Storm Forecast

Valid: Thu 15 Dec 2011 06:00 to Fri 16 Dec 2011 06:00 UTC

Issued: Thu 15 Dec 2011 06:33

Forecaster: GATZEN

SYNOPSIS

Another strong jet stream spreads across the northern Atlantic into western Europe. A deep trough located downstream will rapidly move eastwards. It will affect central Europe from France to Poland. The southern part of this trough will move south-eastwards and is expected to cross the Adriatic reaching Greece at Friday morning. At the same time, the Atlantic jet streak and an associated intense surface low will approach western Europe.

DISCUSSION

North Sea region

A trough will rapidly move across the North Sea. Moist air masses will be affecteed by lift and instability is likely. Thunderstorms have developed over The Channel and will spread north-eastwards during the day, reaching Denmark later on. Given strong low-level vertical wind shear near the coasts, a tornado is not ruled out. Overall threat seems to be marginal, though.

TORRO and SkyWarn still have old watches up currently and UKASF must be on holiday in the Caribbean!

Here's a few convective charts for the day while I go and have a look for the windy stuff:

Look at that coming in form the Atlantic - a precursor for tonight?

But note how the jet is pushing it down into France.......

[Buzzard]

Well by the looks of the BBC1 forecast, my run to the station at 7am tomorrow morning is not going to be pleasant!!

cold, wet snow.

[Coast]

It looks like the jet could play a part in the 'will it, won't it' part of any potential severe storms for the South of the UK later today.

Currently it is pushing stuff way down into France:

That looks like it carries on through the day such that the expected winds are now further South????

The gusts also look like being severe, but now across France:

Those are obviously GFS charts, here are a few indicators from elsewhere:

The low moves in across the Southern coast of the UK and the worst of the isobars are in France:

But we are still in for an awful lot of rain!!!!!

Things are not as bad as indicated earlier in the week, but still a concern in France:

With maybe a hint of stronger winds and helical activity along our Southern most areas:

The strongest gusts look like they might just skim the seafronts of the SE:

All in all, we may just be lucky that any worrying stuff has subsided a little and is more to our South - still interesting to follow none the less!

[geoffw]

do you forsee any more potential major storms for the UK? RJS?

[Coast]

Of course, on everybody's mind is the 'S' word :unsure:

This looks pretty spot on to me:

Snowfall for 12 hrs ending Fri 16 Dec at 12am GMT

[NO LONGER POSTING]

WOOOOW snow potential!!!

[Eskimo]

Great snow potential

[dallas]

Morning Coast,

Could a strong low system pull away from a strong jet stream/

[Liam J]

NMM model highlights the risk of snowfall, particularly over Northern England and Central/SE areas, plenty going on over the next 24 hours or so.

Also it could turn very icy looking at the ground surface temps.

Edited December 15, 2011 by Liam J

[NO LONGER POSTING]

Well some of us in he South east could wake up too 1-5cm of snow tomorrow I reckon BRING IT ON!! WWOWOWOOWOWWOWO!!!!

[Eskimo]

Well some of us in he South east could wake up too 1-5cm of snow tomorrow I reckon BRING IT ON!! WWOWOWOOWOWWOWO!!!!

Surrey is always a prime spot for snow!

[Coast]

Morning Coast,

Could a strong low system pull away from a strong jet stream/

Owww now you're asking me scientific questions and I only do pictures and graphs!!! People like Nick F and Chiono are the guys to ask about that. I just see that big rush of wind at high level coming down to the UK and making a right turn and think that might affect where that LP tracks later.

I really think form what I've seen this morning, that the extreme South coast might get some winds like Tuesday, but the big stuff is over France - that's gut feel though, no cleverness! Snow maybe as indicated on the various charts posted above here, but nothing to go sledging in

[Lt. Dan]

How important is the wet bulb temp at 850hpa for any snow risk?

Does this need to be a lower temp, ideally?

[Liam J]

A look at the GFS 6z charts which back up the NMM regarding potential snowfall into Friday morning, as ever don't take them as gospel but I'm sure a few surprises will occur as the depression moves through.

Whilst dew points could do with being lower, they are not excessively high for snowfall but one thing that may ruin it is the wet bulb which is around 1-2c away from the coastal areas, which are even higher.

Edited December 15, 2011 by Liam J

[conor123]

Anyone know if the low's further north or south or on track even of where it was meant to be??

[dallas]

Owww now you're asking me scientific questions and I only do pictures and graphs!!! People like Nick F and Chiono are the guys to ask about that. I just see that big rush of wind at high level coming down to the UK and making a right turn and think that might affect where that LP tracks later.

I really think form what I've seen this morning, that the extreme South coast might get some winds like Tuesday, but the big stuff is over France - that's gut feel though, no cleverness! Snow maybe as indicated on the various charts posted above here, but nothing to go sledging in

LOL cheers coast, i shall ask away

[johnholmes]

A look at the GFS 6z charts which back up the NMM regarding potential snowfall into Friday morning, as ever don't take them as gospel but I'm sure a few surprises will occur as the depressions moves through.

Whilst dew points could do with being lower, they are not excessively high for snowfall but one thing that may ruin it is the wet bulb which is around 1-2c away from the coastal areas, which are even higher.

one word of caution

As ALWAYS when trying to predict will it snow for my location-first check is the ppn chart, if its not get any then you will not get any snow no matter what the snowfall predict charts may show!

won't let me post the relevant ppn chart from Extra for some reason so maybe this link will be allowed?

http://www.netweather.tv/secure/cgi-bin/premium.pl?action=gfsbasic;sess=8873c7869b9af25dc422793aed06f2fa

[Liam J]

Anyone know if the low's further north or south or on track even of where it was meant to be??

Hi Conor, well atm everything looks as it should do with the current track and position of the low.

Still on course to zip through the channel with rain/snow over the UK and the strongest winds reserved for the channel and parts of N France.

[knocker]

Morning Coast,

Could a strong low system pull away from a strong jet stream/

As far as I'm aware this does happen on occasion and you get what is called cut-off lows but I'm sure we are not in that situation so I wouldn't worry about it. Of course I'm open to correction as always.

Edited December 15, 2011 by weather ship

[johnholmes]

just posted this in the model thread so probably relevant in this one too

Re the queries about snow for 'me'

Do remember just how difficult it is to get rainfall totals, intensities and locations correct even 12 let alone 24 hours out.

For snow then add on at least another 9-10 other variables and you should see just how complex is the forecasting problem. Go to the Guides and dig out the 'will it snow', remembering to factor in any altitude corrections and the proximity of the sea if the low level flow is off the sea.

[Coast]

Please remember, this article is from the Daily Mail - nuff said?

The big freeze set to last all weekend... and batten down the hatches tonight because there's another 70mph storm on the way!

• South coast of England to be hit with winds of up to 70mph overnight,
  
• Snow set to hit Wales, the Midlands and possibly south east England
  
• Up to 10cm of snow could fall in Shropshire, mid Wales and West Midlands
  

Britain's big freeze is likely to last until Monday with icy conditions and snow adding to the misery today and tomorrow.

The Met Office has issued severe weather warnings of icy conditions across most of the country this morning, with a storm heading in this evening bringing more nasty weather. It is likely to move along the south coast of England, bringing winds of up to 70mph overnight, with snow set to move in the early hours of tomorrow morning over Wales, the Midlands and possibly south east England. Wales and central England could see snow from the early hours of tomorrow morning, possibly settling even at low levels, and up to 10cm on higher ground in Shropshire, mid Wales and parts of the West Midlands as heavy rain brought by a low pressure system turns to snow in the early hours of tomorrow.

Up to a centimetre of snow could fall by dawn over parts of south east England. Britain will stay in the grip of the big freeze - the Met Office said colder-than-average temperatures are set to continue through tomorrow and the weekend. It has issued warnings of icy weather for the whole of the country for Saturday and Sunday, and conditions are only predicted to improve on Monday.

Paul Mott, forecaster with MeteoGroup, the weather division of the Press Association, said: 'We have got a deep low pressure system moving in from the west that is expected to track eastwards across the English Channel. 'The good news is that the strongest winds associated with this low pressure system will probably be over the English Channel and over France. There will be some gale force winds over France probably overnight. 'There will also be winds over the south coast of maybe up to 60 miles per hour.

'I think locally we could see up to eight centimetres of snow over some of the hills of Shropshire, across mid Wales and the far west of the Midlands.'

Temperatures are set to remain cold over the weekend with a range of between 3C and 6C during the day (between 37F and 43F) and at night there will be widespread frosts with temperatures plunging to between -1C and -4C (25F to 30F), forecasters said.

The Met Office also forecast colder-than-average temperatures through tomorrow and the weekend.

Chief forecaster Anthony Astbury said: 'The unsettled weather over the next few days could bring a range of hazards across the country, from snow and ice to heavy rain and strong winds. 'We're working closely with Government agencies and the resilience community to keep them up to date with the latest information.

'We'd advise the public to regularly check our latest forecasts and warnings to stay up-to-date with the situation.'

The country has been battered by weather for a week. On Monday high winds and heavy rain hit England and Wales - one man had a lucky escape when a tree smashed into his bedroom while he was asleep in Winchester, Hampshire. Last Thursday a storm left thousands of homes without electricity and caused widespread school closures. Snowfalls coated the ground as far south as Exmoor in Devon yesterday and continued to sweep across large parts of the north, as well as Scotland and Ireland as winter well and truly made its

Homes have already been evacuated and left without power around the country this week, as roads were closed, ferries cancelled and flood warnings put in place as 60mph winds swept in. Dan Williams, Met Office forecaster, explained: 'The storm that was heading in is looking like it is going to take a more southern track.

'It means that on the northern side, there will be more cold air so that means there's a risk of snow that will cover much of the north, Wales and the Midlands. 'Exactly how much, it's hard to say but we're looking at the risk of a couple of centimetres at low level and more on higher ground. 'We're also looking at some fairly suppressed maximum temperatures by Friday of about 39F (4C) as the top temperature. 'It's a similar story for Saturday, and overnight it will be 32F (0C) with some places going down to 30.2F (-1C). 'It is slightly below average for this time of year. The maximum average during the day for December is 44.6F (7C).'

Earlier this week in Charvil, Berkshire, a van full of money being taken to fill cash machines was abandoned after becoming stuck in a swollen ford, which rose 2ft in 24 hours. The van had to be winched by firemen out of the River Loddon. In Bexhill-on-Sea, East Sussex, dozens of people had to flee after gusts of wind stripped the roof off a block of flats. High winds also swept away an anti-capitalist camp in Brighton.

At Burgess Hill, West Sussex, the storms raised fears for a pensioner who disappeared after walking his wife to work on Monday. Police believe Eric Price, 79, who had talked about going to Eastbourne, may have become lost or confused while travelling on public transport. Meanwhile in the Atlantic, two rowers were forced to spend the night in a life raft in the middle of the freezing ocean after their boat was capsized by a freak wave.

Briton Tom Fancett and his Dutch colleague Tom Sauer were taking part in the Talisker Atlantic Challenge, rowing from the Canary Islands to Barbados. The pair, of whom one is British and the other is a student at St Andrews, were amazingly unharmed when they were rescued by a cruise ship this morning. In West Chiltington, West Sussex, a family of four had an amazing escape after stormy weather sent a tree crashing through a conservatory used as a play space by their children. Mike and Katie Gower, aged 46, were sitting in the living room of their bungalow shortly before going to bed when the branches shattered the glass and aluminium structure. 'It sounded like a loud clap of thunder initially but then I quickly realised it wasn't,' said management consultant Mr Gower, 59. 'We've got trees all around but they are quite far back. I'm quite shocked by the situation really - it's not like we hadn't been in that room 'It's usually a playroom for the children and their toys were in there. My wife had put some toys away about an before it happened so she's quite lucky she wasn't in there when it happened. It's just a nightmare.'

Children Jamie, six, and Isobel, nine, were tucked up in bed on the other side of the house. Meanwhile in Scotland, severe weather warnings of snow were issued on Tuesday – with gusts of up to 80mph expected. Heavy snowfall above 200 metres could lead to blizzard conditions. The alert follows last Thursday’s storm, which battered the country leaving thousands of homes without power. The bad weather also forced a seal pup to find sanctuary with a flock of sheep after being driven ashore by winds in Holm, Orkney. The pup, nicknamed Snowy, was separated from his colony and crawled into a field full of sheep where he fell asleep.

Tom Tobler, of Meteogroup, the Press Association's weather arm, said that today and Friday would potentially see 'the strongest winds of the week'. He said 70mph gusts had been recorded in Devon, and were likely to continue. 'Anywhere along the south coast could see gusts of up to 70mph,' he said. 'It is windy everywhere particularly around the western and south coasts.'

http://www.dailymail...l#ixzz1gbB9Zy4R

[Liam J]

Please remember, this article is from the Daily Mail - nuff said?

http://www.dailymail...l#ixzz1gbB9Zy4R

Hmmmm..... ?

Edited December 15, 2011 by Liam J

[Harry]

Hmmmm..... ?

Indeed...because there's a whole raft of reliable newspapers when it comes to the weather