Spring Model Discussion 18Z 6/3/13 onwards....

[Nick F]

GFS suggesting east/northeasterly gales across the SW and through the Channel on Monday, with temps progged at 0-1C max across southern England, that's going to feel perishingly cold!

With winds sustained of at least 25mph along the south coast, using calculator below, we could be looking at wind chill of -8C, exceptional for March.

http://www.hpc.ncep....windchill.shtml

Edited March 8, 2013 by Nick F

[Cheshire Freeze]

Crewe we want that scandi surface High!!!

For me I will be praying PTB 2 comes home to roost.

http://www.meteociel...=2&mode=0=

48 hours of snow in the S/SE starting T48 & ending @ T96 - then a -13c reload from the east at 144 via a scandi surface ridge.-

Watch for the surface ridge tomorrow........!

S

Hi Steve, a scandi surface ridge is fine but the one showing up on the 12z was situated around the low countries, deflecting LP NE rather than SE.

The consequence was a lot of SW'lys/S'lys

Like this...

Edited March 8, 2013 by CreweCold

[bradymk]

Crewe we want that scandi surface High!!!

For me I will be praying PTB 2 comes home to roost.

http://www.meteociel...=2&mode=0=

48 hours of snow in the S/SE starting T48 & ending @ T96 - then a -13c reload from the east at 144 via a scandi surface ridge.-

Watch for the surface ridge tomorrow........!

S

Yes with a west based -NAO developing, Peterb 2 shows nicely how we could stay on the cold side. V cold again 144 to say 216.

[Purga]

If only!

Anyway, there was only 1 lone member getting the precipitation that far north on the 12z, now there's 4 or 5. It's a start!

C'mon you guys in the north get loadsa snow all the time, leave this little number to us in the south on Mon-Wed we need a decent dump - badly! LOL

[LomondSnowstorm]

If only!

Anyway, there was only 1 lone member getting the precipitation that far north on the 12z, now there's 4 or 5. It's a start!

It is, this feature wasn't really showing its hand this side of the Channel at all 24 hours ago, though I'm not sure how much more of a correction is likely. There's a trough moving in through the day Sunday to the northern half of Scotland too so either way would suit me!

[Cheshire Freeze]

C'mon you guys in the north get loadsa snow all the time, leave this little number to us in the south on Mon-Wed we need a decent dump - badly! LOL

Pffft you should try living here. The snow in Jan was the deepest I've seen it for many a year.

P.S RE the dump, I've heard senokot is quite good

Edited March 8, 2013 by CreweCold

[Captain Shortwave]

GFS suggesting east/northeasterly gales across the SW and through the Channel on Monday, with temps progged at 0-1C max across southern England, that's going to feel perishingly cold!

With winds sustained of at least 25mph along the south coast, using calculator below, we could be looking at wind chill of -8C, exceptional for March.

http://www.hpc.ncep....windchill.shtml

Yeah exceptional for the time of year. I would say it';s not just the south coast. Areas fully exposed to the wind such as East Anglia, Kent, Lincolnshire could feel the full brunt of this cold North East wind. Even coastal areas have max temperatures of freezing on monday with mean speeds of 30mph or so. I'm not taking a walk down the seafront Monday snow or no snow.

Edited March 8, 2013 by Captain shortwave

[bradymk]

C'mon you guys in the north get loadsa snow all the time, leave this little number to us in the south on Mon-Wed we need a decent dump - badly! LOL

I need a decent dump...badly, before i forget what snow is like. Actually not even a dump, just some falling snow! I think i may have to move though as my location is pretty poor and this winter has definitely shown that although if the trend northwards continues, even I might finally see some proper snow for the first time this winter. My friends in parts of the SW and particularly Cornwall and Devon will agree with me, and some of the Irish!! On the plus side, my location is one of the best come the summer!! Edited March 8, 2013 by bradythemole

[nick sussex]

Oh the nerves will be shredded for those in the high risk snow area.Each run from now to then will be put through the microscope.

These set ups aren't good for those of a nervous disposition, theres a part of me that's quite relieved that I'm living here now, I don't think I could cope with all the stress if I was still living in West Sussex!

Certainly you have all the ingredients for a good snow event, a steep gradient, very cold undercut, low dew points.

It's just a matter now of how much deepening happens to that low, how far north the snow gets and how long it lasts for.

I look forward to seeing how this plays out,the snow totals if things come together favourably could be quite something.

[TEITS]

Certainly can see the uncertainty with regards to the snow for the S.

Check these 18Z ensembles for Dorset and note the scatter compared to say Cambs.

http://cdn.nwstatic.co.uk/ensimages/ens.20130308/18/t850Dorset.png

http://cdn.nwstatic.co.uk/ensimages/ens.20130308/18/t850Cambridgeshire.png

If I lived along the S coast I would be excited at the potential but also nervous if the less cold air pushes further N than currently suggested by the operationals.

[Purga]

Oh the nerves will be shredded for those in the high risk snow area.Each run from now to then will be put through the microscope.

These set ups aren't good for those of a nervous disposition, theres a part of me that's quite relieved that I'm living here now, I don't think I could cope with all the stress if I was still living in West Sussex!

Certainly you have all the ingredients for a good snow event, a steep gradient, very cold undercut, low dew points.

It's just a matter now of how much deepening happens to that low, how far north the snow gets and how long it lasts for.

I look forward to seeing how this plays out,the snow totals if things come together favourably could be quite something.

I do Nick and on the Coast! It's going to be torture over the next 48hrs - can I stand it? Will it be worth it? A few flakes, sleety rain or snowy Nirvana? We must be mad putting ourselves through all this.

[nick sussex]

I do Nick and on the Coast! It's going to be torture over the next 48hrs - can I stand it? Will it be worth it? A few flakes, sleety rain or snowy Nirvana? We must be mad putting ourselves through all this.

Yes I can see many people viewing tomorrows output from behind the sofa! It's nerve jangling of the highest order because of the uncertainty regarding how far north any snow will get.

[Jimmy0127]

I often see similarities between following the weather and following a team - if ever there was a commentator, Nick from Sussex/Pyrenees would be it (and a good one too.) Cheers Nick for your ongoing insight on this forum - you're in a pretty fascinating weather location yourself - I'd find it hard to care about the weather in Southern England!

[nick sussex]

I often see similarities between following the weather and following a team - if ever there was a commentator, Nick from Sussex/Pyrenees would be it (and a good one too.) Cheers Nick for your ongoing insight on this forum - you're in a pretty fascinating weather location yourself - I'd find it hard to care about the weather in Southern England!

Thanks, that's nice of you. Well although I've lived here now for 5 years I still when it comes to snow seem to be more interested in what happens in the UK, I think its because I spent so many winters there where a cm of snow was all you got if you were lucky so I do like to see my fellow snow fanatics get a bit of luck on that front.

Edited March 9, 2013 by nick sussex

[Jimmy0127]

Well I hope so. My old man on the other hand - moved his business three days ago to the top of the South Downs - was not amused by my enthusiastic snow message!

No, but I don't want to boost your ego or anything, but your posts always seem to be quite informed and rational, inquisitive and (dare I say it) respectful. And thanks for that.

[chris55]

GEFS for London highlights the uncertainty with the track of this low well, plenty of scatter with the 850s and the ppn spikes are plentiful.

It is nice to have a late shot at some snowfall! Tomorrows runs will be fun.

[LomondSnowstorm]

I kind of agree with the general sentiment about the map excluding Scotland and Northern Ireland but if you're going to use meteociel or wetter those are the most high resolution maps so it does make sense.

The alternative of course for precipitation type is netweather:

I am expecting eastern Scotland to see snow Sunday into early Monday too so it's not an all south affair, though the front specifically is.

[Roger J Smith]

Higher elevations of the southwest would surely get a blizzard out of this approaching storm, coastal regions more of a mix but wind and waves on south coast will be hazardous. Think it may cut off heavy snow east of IOW as it seems more likely to start moving southeast into Brittany. But parts of Devon, Somerset and Dorset could see 20-40 cm.

The main difference I see so far on the 00z is the cold air clamping down harder on the low and deflecting it faster to the south.

This may reduce snow potential in Kent, southeast and London but otherwise the North Sea very much in play and parts of east Midlands, Yorkshire and northeast could see locally heavy amounts. The southwest however may have isolated snow emergency situations developing given the combination of wind, snowfall and cold.

[Tom Jarvis]

At t96 on the ECM that shortwave that stops heights from building has now gone

Edited March 9, 2013 by Tom Jarvis

[Man With Beard]

All main models keep the shortwave more north-west at T144 this morning, resulting in varying degrees of warmer weather by T144.

In the nearer timeframe, Monday's front doesn't move as far inland and moves away quicker on Monday night. The SW and perhaps southern coastal towns still see decent snow though.

[TEITS]

Higher elevations of the southwest would surely get a blizzard out of this approaching storm, coastal regions more of a mix but wind and waves on south coast will be hazardous. Think it may cut off heavy snow east of IOW as it seems more likely to start moving southeast into Brittany. But parts of Devon, Somerset and Dorset could see 20-40 cm.

The main difference I see so far on the 00z is the cold air clamping down harder on the low and deflecting it faster to the south.

This may reduce snow potential in Kent, southeast and London but otherwise the North Sea very much in play and parts of east Midlands, Yorkshire and northeast could see locally heavy amounts. The southwest however may have isolated snow emergency situations developing given the combination of wind, snowfall and cold.

Have to be honest Roger I find the above rather OTT if you don't mind me saying and here is why.

Firstly suggesting amounts of 20-40cm is unlikely even with a direct hit. However at the moment the models keep suggesting just a glancing blow from this LP rather than a direct hit. Those in the extreme S could still see more than the models are suggesting but even then I really can't see 20-40cm. Further N and whilst I am expecting snow showers to be fairly widespread im still not expecting them to bring heavy accumulations.

What we have to take into account is if these synoptics occurred in Dec or Jan they would of delivered far more snowfall compared to now. The combination of the colder SSTs, longer daylight hrs, stronger sun, higher ground temps all must be taken into account.

[winterof79]

Cold now encroaching with rain turning to snow today and overnight for some

http://expert-images...030918_0900.gif

http://expert-images...031000_0900.gif

Snow showers moving in from the east thereafter for the central belt of the UK.

Hint of a front brushing the east overnight into Monday and a risk of more general snow for the far south

http://www.meteociel...fax48s.gif?08-0 and more general snow associated with a low forming to our n/e moving down the

country on Tuesday in to Wednesday

http://www.meteociel...fax84s.gif?08-0

It must be noted that the risk of freezing rain is also there for the south.Also for parts further north the risk of ice on trees and power lines due to the quick undercut later today.

Edited March 9, 2013 by winterof79

[IDO]

Short term the front over the weekend should bring snow to many though the further east the better chance of settling according to GFS:

The southern event Monday beginning to look borderline. Accumulations from GFS suggest the main snow thrust to the UK's south, N. France: Still some around and plenty time for this to edge north (or further south) 18z (last night):

So a downgrade overnight.

Next week looks cold for all. Possible wintry showers but nothing of note at the moment.

The 0z GEFS suggests a split in synoptics around D6 with the mean dragged up, so the trend is for the Atlantic to show its hand. There are still a few members maintaing a colder outlook but run to run this return to average has been the movement:

Though the 0z is one of the mildest FI options: ECM may be closer to the mark at D10, with -4c uppers over the London whilst GFS has +4c uppers (mean GEFS -2c):

ECM: GFS: So FI still open to change.

Edited March 9, 2013 by i'm dreaming of...

[Severe Siberian icy blast]

Have to be honest Roger I find the above rather OTT if you don't mind me saying and here is why.

Firstly suggesting amounts of 20-40cm is unlikely even with a direct hit. However at the moment the models keep suggesting just a glancing blow from this LP rather than a direct hit. Those in the extreme S could still see more than the models are suggesting but even then I really can't see 20-40cm. Further N and whilst I am expecting snow showers to be fairly widespread im still not expecting them to bring heavy accumulations.

What we have to take into account is if these synoptics occurred in Dec or Jan they would of delivered far more snowfall compared to now. The combination of the colder SSTs, longer daylight hrs, stronger sun, higher ground temps all must be taken into account.

I have to agree there , it's a bit cringe worthy to hear rogers dramatic take on events every time it's set to turn colder.

If roger can post evidence to back his estimations up then fair enough , but after the failed February from him it's falling on deaf ears I'm afraid mate. No offence Roger

[fine wine]

Higher elevations of the southwest would surely get a blizzard out of this approaching storm, coastal regions more of a mix but wind and waves on south coast will be hazardous. Think it may cut off heavy snow east of IOW as it seems more likely to start moving southeast into Brittany. But parts of Devon, Somerset and Dorset could see 20-40 cm.

The main difference I see so far on the 00z is the cold air clamping down harder on the low and deflecting it faster to the south.

This may reduce snow potential in Kent, southeast and London but otherwise the North Sea very much in play and parts of east Midlands, Yorkshire and northeast could see locally heavy amounts. The southwest however may have isolated snow emergency situations developing given the combination of wind, snowfall and cold.

As ever John, thank you for your contribution. I think your correct for higher elevations if the low approached as currently modeled. It does seem however there has been a trend for this low to be shunted into France and therefore this option is looking less likely. I wish we could get the battle ground situations like you guys do over in Canada!