Significant Snow Risk This Weekend - General Discussion

[ZONE 51]

Created a snow map

Edited February 4, 2012 by ElectricSnowStorm

[Snowmad79]

Created a snow map, il get some info up in a while for it.

Good to see ya just about got us in the high risk zone... gut feeling of getting 15cm+ here

[ZONE 51]

NAE 00z

Precipitation area 1800hrs-0000hrs

dew points staying 0c or below all down the eastern side

chart is 0000hrs-sunday

if we go back to 1500hrs and look at the dew points(below)

the best for snowfall east of the blue line there,

next is the 850-1000hpa, you can see the blues where the coldest air is at 1500hrs-best for the snowfall, out east deep cold block is clear to see as purples, the Atlantic weather system is pushing up against this very hard to shift block of cold air, this creating alot of snowfall for many areas,

next is same chart at 1800hrs,

the very cold air stays over the east side-nearest to where the severe cold is coming from,

down in the SW the warmer sector can be seen by the lighter greens there,

looking at the surface temperatures for that same time as chart above at 1800hrs you can see the warmer air at 10c off the SW coast, with the cold block to the east, this is creating a battle ground frontal system, if you are on the right side of the front then the snow is yours!

Edited February 4, 2012 by ElectricSnowStorm

[knocker]

The METO haven't updated last evenings position as yet aithough I'll be interested to seethe o600z chart. So....

[MKN]

not alot of action first thing anyway just checked the nae looks like rain for many now north or west of London.... Just kidding looks great still. If anything a couple extra mm added to many areas. 5-10cms could easily be 10-15 over a relatively large area by our standards.

[Snowmad79]

MattHugo81 Matthew Hugo

NW Eng/E Lancs: SEVERE WEATHER WARNING - Snow expected from noon onwards through the afternoon. 2cm to 5cm generally, but upto 10cm possible

6 minutes ago

[West is Best]

eh?Every single model has heavy snow over the bulk of england, and the met have an amber warning for heavy snow for a large expanse on the country. All this at about 30 hours out, and the only reason you have to go against all of this is "it looks wrong" What is that supposed to mean WIB. Please enlighten me and everyone else on this thread as to what you are saying, as it makes absoluetly no sense to me, a very misleading post IMO. Only above 300m and even then only in the north and east ? I would bet my house agaisnt this. Its certainly not a typical battleground setup, but how do you propose the cold uppers over us right now will be removed so easily?

Zakos et. al. no need for any vitriolic posts (TEITS you should know better). My issues with this setup are that upper air temps may rise in advance of the preciptation so that rather than a true undercut we have a gradually rising temp situation hence my suggestion that most places may have 2 or 3 hours of snow before it turns to sleet and then rain. I do acknowledge this is an unusual setup given the cold pooling ahead of this angle of attack, but it's not one that is traditionally associated with snow in this country. There is no easterly off the leading edge: the fronts advance with gradually rising temperatures.

And on that subject, whilst I'm about it, TEITS that was unfair. I suggested the Atlantic would win this battle, that we would not have a dominant easterly and I believe that has been correct.

So, charts to support my extremely marginal theory? How about the 0z GFS? Admittedly that shows the south-east corner has good prospects but elsewhere it's pretty marginal with any snow readily turning back to rain after 2 or 3 hours. In a marginal situation the METO will always now err on the side of caution, as they get it more in the neck for under-warning than over-warning.

I'm returning to my London flat tomorrow morning and have booked my train ticket, just to show that I put my money where my mouth is!

Seriously though, I hope I'm wrong. I may well be!

Edited February 4, 2012 by West is Best

[ricey076]

Low of -5 ! On the coast here in cleethorpes !

[divadee]

-10.4 here in the normally mild christchurch! Stil don't think we will see the white stuff a lot here but never say never!

[Ian Suffolk]

Snowing quite heavily here in Suffolk. Must admit its a tad unexpected! Not complaining though!

[Great Plum]

I understand Richard's (WIB) pessimism here... Whilst this is a highly unusual setup, I don't remember (I'm 30) there being frontal snow from the west that lasted... This looks like it could be different at least for those in the south east...

[snow drift]

I understand Richard's (WIB) pessimism here... Whilst this is a highly unusual setup, I don't remember (I'm 30) there being frontal snow from the west that lasted... This looks like it could be different at least for those in the south east...

It will be interesting to watch this unfold. Need a thread for guess the most westerly place that gets snow only. I would guess at Milton Keynes.

[knocker]

I understand Richard's (WIB) pessimism here... Whilst this is a highly unusual setup, I don't remember (I'm 30) there being frontal snow from the west that lasted... This looks like it could be different at least for those in the south east...

I don't see it as that unusual. If a warm front from the west slows down in the battle with the cold air then significant snowfalls can occur.

[Iceberg]

totally agree ws, it might be a difficult thing to forecast, but it's not very unusual (being in the west we get these set ups most winters as we normally end up missing out from them ! ).

the nae is showing snow for 6-12 hrs for a big massive central belt from liverpool in the west across york and to lincs in the east and all the way down this isn't a se event, whatever wib is saying. I would suggest people walk through the NAE charts and see for themselves.

[Great Plum]

I don't see it as that unusual. If a warm front from the west slows down in the battle with the cold air then significant snowfalls can occur.

Maybe I should rephrase... It's unusual in my memory in the south east...

[Yorkshiresnows]

Zakos et. al. no need for any vitriolic posts (TEITS you should know better). My issues with this setup are that upper air temps may rise in advance of the preciptation so that rather than a true undercut we have a gradually rising temp situation hence my suggestion that most places may have 2 or 3 hours of snow before it turns to sleet and then rain. I do acknowledge this is an unusual setup given the cold pooling ahead of this angle of attack, but it's not one that is traditionally associated with snow in this country. There is no easterly off the leading edge: the fronts advance with gradually rising temperatures.

And on that subject, whilst I'm about it, TEITS that was unfair. I suggested the Atlantic would win this battle, that we would not have a dominant easterly and I believe that has been correct.

So, charts to support my extremely marginal theory? How about the 0z GFS? Admittedly that shows the south-east corner has good prospects but elsewhere it's pretty marginal with any snow readily turning back to rain after 2 or 3 hours. In a marginal situation the METO will always now err on the side of caution, as they get it more in the neck for under-warning than over-warning.

I'm returning to my London flat tomorrow morning and have booked my train ticket, just to show that I put my money where my mouth is!

Seriously though, I hope I'm wrong. I may well be!

Sorry, but really don't get where you are coming from .......... other than you are winding folks up on purpose.

Central belt East countrywide 5-10 cm with it freezing over night where the snow clears.

There is no Atlantic dominated theme in the medium term as you constantly were suggesting was likely a few days ago.

Wouldn't at all be suprised if the front begins to stall and more snow falls further West ...... but we shall see.

Y.S

[snow drift]

The one thing that isn't being spoken about but is arguably more dangerous than snow is rain hitting frozen surfaces. Although this will be a relatively short period of time, it could be a real problem. Snow you can see, Ice is more difficult. So if it starts as rain in your area then be mindful of this until the cold is out the ground.

[West is Best]

I don't see it as that unusual. If a warm front from the west slows down in the battle with the cold air then significant snowfalls can occur.

The reason it's so unusual is two-fold. First there is deep cold pooling in advance of the fronts. Second though the direction of the fronts is moving down the country from north to south, or rather from north-west to south-east. That's actually the opposite line of advance for snow in the UK off a warm front, and were it not for the deep cold ahead there would be no question that it would fall as rain. Normally when fronts approach from the west to bring snow in the UK it is those north of the centre of the low who get it because the fronts 'present' on a west-east axis and hence an south-easterly through north-easterly direction, pulling in the much colder continental air. When the front stalls that becomes a classic for significant snowfall. When the low tracks along the channel, as in a 'channel low' it can be superb for southern England.

In 40+ years I've never seen significant snow off the direction of these fronts with an advancing warm front.

My big worry with this one is that there is no proper undercut. I fear temperatures will just gradually rise and without the undercut the ppn will turn very readily to rain.

Hope the above makes clearer the science behind my thoughts. Just my take.

The one thing that isn't being spoken about but is arguably more dangerous than snow is rain hitting frozen surfaces. Although this will be a relatively short period of time, it could be a real problem. Snow you can see, Ice is more difficult. So if it starts as rain in your area then be mindful of this until the cold is out the ground.

A very very good point, and something that's been going through my mind. Potential freezing rain scenario this one, or rain onto freezing surfaces.

Edited February 4, 2012 by West is Best

[knocker]

Currently here 8/8 As with Sc but no rain as yet. The 0600z plots and fronts.

[nick sussex]

The one thing that isn't being spoken about but is arguably more dangerous than snow is rain hitting frozen surfaces. Although this will be a relatively short period of time, it could be a real problem. Snow you can see, Ice is more difficult. So if it starts as rain in your area then be mindful of this until the cold is out the ground.

Yes thats a very good point and could be an issue even here in sw France, the same system expected to effect the UK is forecast to slip south into Iberia, running through this region, still some uncertainty with where the snow and rain divide will be.

At the moment its expected to be further west than me but could still change.

The temperatures have been exceptionally cold even for this region, of course all this dense cold over France is good news for the snow chances in the UK, the surface flow looks to be southerly ahead of the precip and this should pull in some low dew points.

Still wondering whether there might be some intensification of that precip as that shortwave hits the Channel so perhaps areas just inland to the east of that could get some benefit if that occured.

[mikeocarroll]

Precipitation so far seems to be roughly where the models expected, no sign of the front stalling. Falling as rain on the south west fringes of Wales as forecast.

[WINTRY WALES]

Snowing nice and steady already in South East Wales. Light Covering over everything. Earlier than expected??

[TEITS]

I suggested the Atlantic would win this battle, that we would not have a dominant easterly and I believe that has been correct.

If you don't mind me saying but how on earth you can make this statement is beyond me. Firstly its currently -7C where I am which doesn't suggest Atlantic dominated weather. The front tonight is now going S because of the blocking to our NE and into next week HP reasserts itself.

As for tonight and I shall leave the chart below to speak for me.

[Pompey Keith]

A very chilly start here in North End, a few miles from the sea. Hard frost and car windscreens thick with ice. Off to take the dog out before we get our snizzle and rain

[nanu]

well lets see if West Is Best is right?? or we will make him eat that hat in his photo. The day well tell its story.. you do realise that as soon as you start typing everybody is going boooooooo.. its like your the villian of a pantomime.. anyway according to rain today its already snowing in the west and so far its all going by what the met said yesterday... Should be very interesting in this corner later, kent has already had a covering from last night.