South West England Cold Spell Discussion

[Methuselah]

Here you go, folks.

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The depressing thaw has set in

[snowking]

cheers SK

so with this front pushing into the SW Tues/Wed next week, would you say (with the info we have at the moment) there is a potential risk of heavy snow for the south-west? Just wondering how far the front will push in (central parts, west London?) - with what I've read so far it seems it will push so far then the easterly reloads will fight the front back out to the atlantic - is that about right??

Cheers

Hi There,

Looks very much to me that the Met Office are disregarding the GFS at the moment - whether wrongly or rightly we shall have to wait and see but for that reason we can't really go on the gfs precip charts. UKMO FAX is very suggestive of the occlusion pushing inland much further than on the GFS, with a better flow ahead of the occlusion off the near continent - the problem is afterwards the flow becomes atlantic, so unless we see the LP about 50-100 miles further south it could well be a snow to rain event

But with 48-72 hours to go many things can and will change

Unfortunately with the GFS perhaps being discounted at the moment for the short term, we cant get any real ideas about the dew points etc - hopefully Ian will have an update for us based upon the NAE, MOGREPS, GM etc.

Kind Regards

SK

[lian]

Just walked to the shops and the paths are treaturous! Where the snow is thawing, the sheets of ice under it are exposed. I nearly looked like bambi on ice! Going to be terrible in the morning here me thinks

[theprophecyman]

Hi There,

Looks very much to me that the Met Office are disregarding the GFS at the moment - whether wrongly or rightly we shall have to wait and see but for that reason we can't really go on the gfs precip charts. UKMO FAX is very suggestive of the occlusion pushing inland much further than on the GFS, with a better flow ahead of the occlusion off the near continent - the problem is afterwards the flow becomes atlantic, so unless we see the LP about 50-100 miles further south it could well be a snow to rain event

But with 48-72 hours to go many things can and will change

Unfortunately with the GFS perhaps being discounted at the moment for the short term, we cant get any real ideas about the dew points etc - hopefully Ian will have an update for us based upon the NAE, MOGREPS, GM etc.

Kind Regards

SK

thanks SK

[Evening thunder]

Depending on the flow the upper temps aren't always too important for snow. Apparently.

But I'd guess thats why its a 60% warning and not an 80-90% warning

It depends which model you are following - UKMO and ECMWF may show different

Also, higher res GFS may be needed to view the 850 boundary's

http://www.wetterzen.../fsgfsmeur.html

SOME eastern parts of wales and the SW still at risk due to the continental feed right up until 0c even according to GFS

SK

Thanks for those replies, I knew that we can get snow with 850hpa temps close to zero in the right set up, But I was thinking that surely we couldn't with them above 0!

Thanks that goes some way to explaining it, Lets hope the MetO know something I don't and GFS is wrong and the likes of the UKMO and ECM are right!

[Thermohaline Conveyor]

I have to say, I'm also very lost with the very latest MO 60% weather warning that has been issued for the South West. There is a risk that as the warm sector clears a cooler slot digs South and at the same time PPN projections are intense. I can also see the strong mixing eventually destroying the front as it battles against the strong dominant high. The T850 boundary at the point of cooling is +1/0 to around -1/-2 - there is a possibility that heavy PPN will drag down this cooler boundary close to the surface. I'm not saying that there is not a possibility that some transient snow will be possible across areas close to Somerset/N Devon to higher ground, but on current guidance I don't see snow being the main problem here. Maybe Ian can shine some light on the latest NAE, GM and MOGREPS take on this.

[yipikiaye]

Lots of snow to come then apparently.In actual fact i did know about this several days ago.But thought it would be a non event.Still might be but i think this will turn to snow anywhere away from south coast due to the easterly wind picking up or something.Well thats what i heard anyway sky weather also saying this is a warm front but cause of the strong easterly wind this will change it to snow as it hits land

[BristolBlizzard]

Lots of snow to come then apparently.In actual fact i did know about this several days ago.But thought it would be a non event.Still might be but i think this will turn to snow anywhere away from south coast due to the easterly wind picking up or something.Well thats what i heard anyway sky weather also saying this is a warm front but cause of the strong easterly wind this will change it to snow as it hits land

is this the snow for mid week !! or tonight !

[snowking]

I have to say, I'm also very lost with the very latest MO 60% weather warning that has been issued for the South West. There is a risk that as the warm sector clears a cooler slot digs South and at the same time PPN projections are intense. I can also see the strong mixing eventually destroying the front as it battles against the strong dominant high. The T850 boundary at the point of cooling is +1/0 to around -1/-2 - there is a possibility that heavy PPN will drag down this cooler boundary close to the surface. I'm not saying that there is not a possibility that some transient snow will be possible across areas close to Somerset/N Devon to higher ground, but on current guidance I don't see snow being the main problem here. Maybe Ian can shine some light on the latest NAE, GM and MOGREPS take on this.

Spot on TC

This is why i'm going with the assumption that the GFS has been completely dumped by the Met Office for this one - certainly the FAX is suggestive of this, but we'll get a better idea in a couple of hours with the 12z

Will be very useful to see the NAE this evening, we'll start to see it coming into range for tuesday at 48 hours

SK

[yipikiaye]

Tuesday or wednesday

Im going by what sky weather is saying.The reason it ll be snow as suppose to rain is because of the cold easterly wind.This is what was said last night there words.Personaly i aint even seen a easterly wind yet even though today we was suppose to get it

[snowking]

Just to add we should start to see dews drop by a degree or so in the next few hours - should see anything falling turning back towards snow

SK

[kernowman]

It's been snowing consistently for hours now in the far South West but the total accumulation would be lucky to fill a thimble. It's the most pathetically weak snowfall I have ever seen and it looks like the mild weather will now come in.

On the optimistic side I did read the opening paragraph of the Chapter "The Snowiest Winter 1947" from the book "Frozen In Time - The Years When Britain Shivered". It read "There have been colder winters than 1947 - though not many- but no winter since records began has ever been as snowy. It began gently enough. There had been snowfalls before Christmas and again in early January 1947, but both had melted away within days and by the middle of the month, the temperature was unseasonably warm......The weather then turned colder again on January 20....."

So seeing as we still aren't at the middle of the month yet, who knows how much of a proper winter is still to come.

Edited January 10, 2010 by kernowman

[BristolBlizzard]

Tuesday or wednesday

Im going by what sky weather is saying.The reason it ll be snow as suppose to rain is because of the cold easterly wind.This is what was said last night there words.Personaly i aint even seen a easterly wind yet even though today we was suppose to get it

thanks yipikiaye

[robnor1]

Now this is what i mean about inaccurate forecasts right now we have Met office website "be prepared" advisory for MODERATE RISK for SW england including Wiltshire for Tues/Weds issued at 14.33 and 14.53 today whilst the BBC Points west video forecast on the BBC site for most of the same area timed at 13.53 says a chance of further snow Tues into Weds but LOW CONFIDENCE. Come on we can do better than that can't we?

Make me laugh covering all bets again i think because at least one of them can say they were right and the other is covered too.

Still battling the light snow, 0C and strong winds with drifting today in N Wiltshire ....not.

Personally i don't mind what we get as long as its accuarate but with such division above what chance do us mortals have?.

[Dartmoor_Matt]

Snowing again here. Every reason to be optomistic to be honest... how many times in recent years have we had snow on teh ground, snow falling and the possibility of more snow in 2/3days time?

And then we still have spring and summer! With gorgeously warm sunshine, BBQs and cider.

Glass half full guys. :lol:

[BristolBlizzard]

Snowing again here. Every reason to be optomistic to be honest... how many times in recent years have we had snow on teh ground, snow falling and the possibility of more snow in 2/3days time?

And then we still have spring and summer! With gorgeously warm sunshine, BBQs and cider.

Glass half full guys. :lol:

:lol:

[yipikiaye]

Snowing again here. Every reason to be optomistic to be honest... how many times in recent years have we had snow on teh ground, snow falling and the possibility of more snow in 2/3days time?

And then we still have spring and summer! With gorgeously warm sunshine, BBQs and cider.

Glass half full guys. :lol:

Oh god dont mention that s word..summer i detest the summer and always have done lol.Still ages till that season thats if we even get a summer.Suits me if it rains all the time

[snowdog]

I think it was almost better in the 'old days'.My mum says she had no idea we were to have snow when I was a baby in the winter of 62/63.She just woke one morning and everything was white and lasted that way for several weeks, even down here on the south coast!I would like a nice surprise like that,instead of all these non-events,although I guess I would be sick of it eventually!

[yipikiaye]

The only thing im annoyed at today apart from a few sleet showers ive seen nothing.Not even had any easterly wind which was predicted.But there has been a good thing none of me snow has melted from last tuesday night into wednesdays event.If it stays 2 more days that a whole week which is rather good i think

Temp still at 0.5 c

Edited January 10, 2010 by yipikiaye

[Rich_Clements]

Snowing again here. Every reason to be optomistic to be honest... how many times in recent years have we had snow on teh ground, snow falling and the possibility of more snow in 2/3days time?

And then we still have spring and summer! With gorgeously warm sunshine, BBQs and cider.

Glass half full guys.

I hope we get a good summer this year.

Edited January 10, 2010 by Tribe3000

[lian]

I hope we get a god summer this year.

Me to wuth lots of thunderstorms

[aspire27]

Been out all day so not a clue whats going on with the models today etc.

But all can i say for is THAW! Sudden thaw today, quite out of the blue really....

Can anyone explain to me what happend last night weather wise?

[Snowfan50]

So i guess there has been downgrades today huh, as all i have seen is a few sleet showers.

[Thermohaline Conveyor]

Battleground into Tuesday latest Bias outlook from my point of view:

X = marks the spot where the potential change-over lies when the initial warm sector erodes and cooler air digs in with PPN intensity of heavier pulses lowering the 0oC isotherm to 100M - areas to the E of the red line carry the most risk

3 = areas where snow would be most likely on latest guidance - although the signal is weak/moderate only and is subject to shift

1 = outside the general model scope but could mark the E extent if the system tracked further E - although the blocking does look too substantial for this to actually happen

I find it interesting that during these kind of set-ups, in the past we have seen that classic cold air battle displacement some-where around the Bristol area or close to or just marginally South of the M4 corridor. Right now model guidance generally show a relatively mild upper level being advected from the continent despite recent low level PBL air being relatively cold. The dew point projections although not to be taken to literally at this early stage are marginal to way out at +2/+3 to the West of the line marked X. The right of the line or to the East it covers Dartmoor/Exmoor intentionally - due to the higher topography and terrain in the these areas - despite marginal overall atmospheric dynamics based on latest guidance. We'll see though. I'm fascinated to see the NAE 12Z guidance -0 although we'll need a good few more runs before we start seeing the overall picture due to the T+48 limitation in the model suite that we get.