Model Output Discussion - 5th December - 11th December

[fenland ice]

Where abouts are you?

As the met office had said, potential for wintryness from the midlands northwards. After seeing a sleet shower yesterday, I have woken up to it snowing outside, and I live in central england, on the border with east anglia. I have seen on my iPhone apps radar that the snow has been quite widespread In western areas, sometimes coming in further inland. Nothing substantive south of, say,Manchester. But, snow itself certainly not confined to scotland or high ground, as some said it would be. Where abouts are you? The models, again, are upgrading the length of this polar maritime dominated spell. This looks like lasting quite a long time, with only minor mild blips. Friday, unlike today, has the potential to produce widespread, and in places heavy snow. It wil be a more potent snap. Things are looking good IMO.

[Liam J]

Very significant wind storm event Thrusday/Friday for Northern Britain with severe gale to storm force 11 wind speeds, with gales or severe gales widespread elsewhere. Sub 950hpa storm on the 6z which does not seem to move anywhere very quickly and batters the north with severe winds over a prolonged period. Gusts 80-100mph potentially over Scotland and gusts 70-80mph over Northern England.

This could be a very serious situation developing.

Edited December 6, 2011 by Liam J

[Iceaxecrampon]

06z

Snow down to lower level as the winds get pulled in from the North.

Serious stuff - hope the Jocks will have something on under their kilts.

[Nick F]

Looking a pretty stormy 06z so far, rather nasty looking depression close to Scotland on Friday and another very deep low arriving across Scotland by this time next week.

Given the low heights to the NW with very cold air flooding off NE Canada/Greenland - some deep cyclongenesis upstream over the Atlantic along the polar front.heading our way over the next 7 days or so. Any realistic signs of the Atlantic blowing itself out are a long way off yet.

[Liam J]

Looking a pretty stormy 06z so far, rather nasty looking depression close to Scotland on Friday and another very deep low arriving across Scotland by this time next week.

Given the low heights to the NW with very cold air flooding off NE Canada/Greenland - some deep cyclongenesis upstream over the Atlantic along the polar front.heading our way over the next 7 days or so. Any realistic signs of the Atlantic blowing itself out are a long way off yet.

Some impressive bombing low pressure systems in the coming days, Thursday into Friday looking particular bad for Northern Britain. Also later tonight very strong winds affecting the north and west, gusts up to 70mph and over predicted on the Meto location forecast for my town.

It's been quite a while since the Atlantic has been in full on storm mode, with no sign of much if any respite.

Edited December 6, 2011 by Liam J

[Paul_1978]

Look how tightly wound up those two lows are. Almost twins.

http://www.wetterzentrale.de/pics/Rtavn721.png

Looks like two eyes and a mouth to me!

[Thundery wintry showers]

Surprisingly strong agreement out to T+168 on the three main models this morning. That rather scary low for Thursday/Friday appeared on one of yesterday's UKMO runs but I discounted it as GFS and ECMWF went for a watered-down version, but this morning all three models agree with yesterday's UKMO run. It reminds me of the low on the 1st February 2008, which ended up causing less damage than feared, but it looks like being pretty wild in northern and eastern Scotland.

Snow potential off this low is up in the air, with the ECMWF going for a more potent NW blast and some snow showers likely from the Midlands northwards on Friday night, but the GFS run wraps more warm air into the low's circulation. In the past, the GFS has tended to be the more accurate on warm air from depression cores, so in the event it probably will only bring a widespread snow cover to northern hills.

There is also strong agreement on the large low early next week. The outlook is zonal and average to cold in the north, average to warm in the south.

[No Balls Like Snow Balls]

Surprisingly strong agreement out to T+168 on the three main models this morning. That rather scary low for Thursday/Friday appeared on one of yesterday's UKMO runs but I discounted it as GFS and ECMWF went for a watered-down version, but this morning all three models agree with yesterday's UKMO run. It reminds me of the low on the 1st February 2008, which ended up causing less damage than feared, but it looks like being pretty wild in northern and eastern Scotland.

Snow potential off this low is up in the air, with the ECMWF going for a more potent NW blast and some snow showers likely from the Midlands northwards on Friday night, but the GFS run wraps more warm air into the low's circulation. In the past, the GFS has tended to be the more accurate on warm air from depression cores, so in the event it probably will only bring a widespread snow cover to northern hills.

There is also strong agreement on the large low early next week. The outlook is zonal and average to cold in the north, average to warm in the south.

Warm!! yeah ok and I am Mickey Mouse LOL

[legritter]

charts showing some interesting stuff for up north ,i am hoping us down in the south can tap into some of the cold air over the weekend .if this incoming low takes a track a little further south it will have the potential for a similar event that took place back in the 90s i think ,called the burns day storm which inflicted carnage across southern england , .but with the severe stuff this time much further north .this evenings updates could be very interesting .even if everything stays zonal for the next week it should make for an interestig forum .regards

[johnholmes]

The N Sea may well get a storm suge from the weekend low, no idea when and how high high tides are but it could be a problem in places?

[bluearmy]

I know we shouldnt look at far out fi on gfs but the 06z does show the AO going neg in a couple of weeks. i only mention it as i cannot recall an op gfs run showing anything significant of interest for ages in deep fi. the cause of this reversal is events in the north pacific /alaska within 10 days.

[legritter]

as john holmes just said RE high tides ,i think there is a full moon due about thursdayish ,would love to be a fly on the wall down at exeter , and cant imagine but i would think that a lot of emergency planning would be taking place soon IF THINGS UPGRADE QUICKLY ,I HOPE YOU DONT THINK IM SCAREMONGERING , BUT I THINK THERE IS A FAIR POSSIBILITY . TONIGHTS FAX CHARTS COULD BE VERY INTERESTING ,ALSO UPPER AIR TEMPERATURES ,REGARDS

[Snowmad79]

I know we shouldnt look at far out fi on gfs but the 06z does show the AO going neg in a couple of weeks. i only mention it as i cannot recall an op gfs run showing anything significant of interest for ages in deep fi. the cause of this reversal is events in the north pacific /alaska within 10 days.

All the models, GFS included have modelled height rises over the pole before dumping the idea and have done so at some point every week for the past 2 month. Probably a long way off before it does go negative again imo.

[tinybill]

as john holmes just said RE high tides ,i think there is a full moon due about thursdayish ,would love to be a fly on the wall down at exeter , and cant imagine but i would think that a lot of emergency planning would be taking place soon IF THINGS UPGRADE QUICKLY ,I HOPE YOU DONT THINK IM SCAREMONGERING , BUT I THINK THERE IS A FAIR POSSIBILITY . TONIGHTS FAX CHARTS COULD BE VERY INTERESTING ,ALSO UPPER AIR TEMPERATURES ,REGARDS

just looked local tides hight 3.8 ipswich weekend

[shedhead]

just looked local tides hight 3.8 ipswich weekend

Is that a big tide for Ipswich?

[johnholmes]

http://www.yr.no/sat..._animasjon.html

The N Sea may well get a storm suge from the weekend low, no idea when and how high high tides are but it could be a problem in places?

I do think this is looking a serious matter for some parts, as well of course, as the severe gales for northern parts.

The Met O Fax charts will probably be the best guide down to T+24 when its then possible to look at actual charts to follow the low, watching pressure falls and rises behind the low to get a good guide on the actual track of the low. Sat piccs of course are invaluable and this link, oops won't show but I'll drop it in asap, is perhaps the best movie sequence currently available-many thanks to whoever gave it to me.

To those on the east coast that are vulnerable I do suggest without wanting to sound OTT that you start to pay close attention to your local authority and Met O ouputs!

the link is now at the top of the post

I must be getting old I should of course said for the storm surge Thursday onwards

jeepers

I will get it right eventually, storm surge Friday onwards, severe gales for the north from Thursday-best I go and lie down a bit!

Edited December 6, 2011 by johnholmes

[memories of 63]

Looking at the NW ensembles, especially for W. Yorks, is it my imagination but are most of the outliers between Dec 14 and Dec 17, all on the warm side? Would this suggest that there is upside potential for a colder outcome?

[IanM]

We've been watching the combination of wind, pressure and tides for a couple of days now. Definitely one to watch closely over the next 48 hours.

[Richie V]

http://www.yr.no/sat..._animasjon.html

I do think this is looking a serious matter for some parts, as well of course, as the severe gales for northern parts.

The Met O Fax charts will probably be the best guide down to T+24 when its then possible to look at actual charts to follow the low, watching pressure falls and rises behind the low to get a good guide on the actual track of the low. Sat piccs of course are invaluable and this link, oops won't show but I'll drop it in asap, is perhaps the best movie sequence currently available-many thanks to whoever gave it to me.

To those on the east coast that are vulnerable I do suggest without wanting to sound OTT that you start to pay close attention to your local authority and Met O ouputs!

the link is now at the top of the post

I must be getting old I should of course said for the storm surge Thursday onwards

jeepers

I will get it right eventually, storm surge Friday onwards, severe gales for the north from Thursday-best I go and lie down a bit!

That was me John!

Yes looking quite serious for some areas, long overdue I suppose. The atlantic has been relitive clam over the past 3 winters.

[Polar Maritime]

Winds will increase during Thursday afternoon and evening and gusts of 60 to 70 mph could become quite widespread across Scotland, with 80 mph gusts possible over exposed coasts and hills.

Heavy rain and hill snow are likely to accompany the strengthening winds but detail this far ahead is impossible to pin down.

Early warnings from the Met Office regarding Thu/Fri.

Blizzards for Scotland maybe..?

Edited December 6, 2011 by snowrob

[Richie V]

Looking a pretty stormy 06z so far, rather nasty looking depression close to Scotland on Friday and another very deep low arriving across Scotland by this time next week.

Given the low heights to the NW with very cold air flooding off NE Canada/Greenland - some deep cyclongenesis upstream over the Atlantic along the polar front.heading our way over the next 7 days or so. Any realistic signs of the Atlantic blowing itself out are a long way off yet.

Careful nick..... I got my backside handed to me on Sunday for saying "expect models to start showing monster lows from sunday 18Z onward"

I'll refrain from saying 'do you have charts to back this up' !!

[johnholmes]

That was me John!

Yes looking quite serious for some areas, long overdue I suppose. The atlantic has been relitive clam over the past 3 winters.

ta Richie-its a very good tool for watching the significant cloud movements, be it frontal or showers.

Note this morning how the low/polar low in the far north moved and perhaps with it how the shower activity has decreased as it moves away to be replaced by the upper cloud moving in from the Atlantic.

[jello]

New warnings out from metoffice for alot of the country -

Winds will increase during Thursday afternoon and evening. The public should be aware that winds are likely to becoming strong enough to cause some local disruption to travel services, and possibly some structural damage to buildings. On Friday morning winds will tend to ease from the west.

Presently Northern Scotland looks likely to experience the strongest winds.

Heavy rain and hill snow are additional hazards that will accompany the strengthening winds. There is also a low risk of coastal flooding on North Sea coasts during Friday.

Edited December 6, 2011 by jello

[johnholmes]

I've got some free time today so I'll do a pdf on where the low is going to form, indeed already started, and why, its probable track etc, sometime this afternoon or early evening.

I know for many on here you already appreciate what is happening and why but it may help new folk to get a better understanding of why our weather is described in climatology books as 'Disturbed Temperate' !

[Richie V]

ta Richie-its a very good tool for watching the significant cloud movements, be it frontal or showers.

Note this morning how the low/polar low in the far north moved and perhaps with it how the shower activity has decreased as it moves away to be replaced by the upper cloud moving in from the Atlantic.

I'm amazed everytime I veiw that sat site. Indeed, that upper jet cloud Is really motoring. Am I right in saying that feature that dropped down from the north toward N Scotland was a polar low?

I and I'm sure many others appreciate your PDF work... Can't wait to veiw it!