Significant Snow Risk This Weekend - General Discussion

[Suburban Streamer]

I'm surprised they don't think it will be snow south of london...

thats only at 8pm as its just starting. the next sequence shows it over the whole south and east

[danm]

Looks like the latest forecast is already picking this up! Snow looks more extensive right down to the coast or near.

Looks to me like there's no precips there at all, remember they are crappy BBC graphics, but fun all the same!

It will snow south of London. Just a little later than that particular graphic.

Saw the 16.57 forecast with Alex Deakin and it had all of SE/EA under snow late tomorrow night, including areas to the south of London. It may be more marginal right on the south coast though.

Edited February 3, 2012 by danm

[kold weather]

Precipitation sequence Saturday.

That matches up with the NMM almost exactly, thats actually amazing agreement, 21z snow starts where I live on both models. Bring it on!!!

Damn, thats another run we've hurdled, I think we are probably one more run suite away from proper now-casting time...

Man i'm pumped for an all nighter tomorrow!

[East Herts Snow]

The amount of times I've seen them signs, 4 inches of snow just isn't severe in my eyes.

Would agree normally, unless this snow fell quickly, as was the case back in 1996. During a football match between Notts Forest and Spurs a squall line pushed South resulting in 3 to 4 inches falling in about an hour and the game had to be called off. I was living in Enfield, North London at the time and remember blizzard like conditions for about an hour.

Also remember the M11 incident back in 2002 when about 5 to 6 inches fell in a couple of hours near Harlow & Stansted. Motorists were stuck overnight and this was just 10 miles North of London!

If you are not used to driving in snow it can be quite tricky.

Edited February 3, 2012 by East Herts Snow

[jethro]

Hmm that's where it starts to unravel for me. I'm more confident on areas East of the South Downs, but will cross my fingers for your part of the World!

Triple point over East Sussex later? - get in there!!!!!

What's so significant about the triple point? On the fax above it looks to be centered slap bang over my house (that's assuming I've understood what a triple point is and have correctly identified it.....).

[johnholmes]

one word=high

3-5cm low ground 5-10cm higher ground would be my current estimate.

One or two comments about the 06Z being a 'downgrade' how I hate that word, just as much as the phrase 'upgrade'. A quick scout round, the Fax chart still shows the centre much as before, the basic numbers of 850 temp/thickness, dewpoint, etc etc, and MOST IMPORTANT the actual precip charts suggest much as the Met O seem to be suggesting.

I'll do the promised simplified update on what the charts, various ones show, once the 12z has got well into next week and given me time to assimilate what they seem to be showing.

sorry ref the above promise carried over from yeaterday-due to other commitments I will not be able to do the simplified collection of charts for Saturday into Sunday-sorry

[Liam J]

NMM is only going for freezing rain west of the Pennines and high ground, how accurate is that model with PPN type forecasting?

Wash out for the west!

[Stuie]

I kind of get the feeling this too good to be true. Monitoring the forums on here from just before Xmas hoping this scenario (like many) would happen and now feel really apprehensive. Don`t laugh but have the feeling of T12 being FI.

[SilverWolf]

I kind of get the feeling this too good to be true. Monitoring the forums on here from just before Xmas hoping this scenario (like many) would happen and now feel really apprehensive. Don`t laugh but have the feeling of T12 being FI.

With regards to snow potential for the majority of England I totally agree! There are so many disagreements this must be the case?

[Great Plum]

The amount of times I've seen them signs, 4 inches of snow just isn't severe in my eyes.

No, but it's enough to stop a motorway!

Thanks for those who said about the snow coming later for south of London in the forecast!

[Pompey Keith]

Moved to Pompey from Essex over a decade ago, and look at Essex with envy now this weekend as looks like they will get plenty of snow! So what are the chances of Portsmouth getting at least a covering? Even just an inch will be great

*NEW* Weather-related puzzles now available on www.twitter.com/jumblgram

[Stuie]

I suppose if something goes wrong tomorrow then maybe Tuesday would bring a smile.

[picog]

I suppose if something goes wrong tomorrow then maybe Tuesday would bring a smile.

In the west, we need something to lift our spirits.

[IDO]

UKMO have been forecasting last night that the snow will clear the SE on Sunday morning turning to rain ("messy" they called it). 24 hours later at 6pm today, its now an all snow event and they are also tying in with GFS's forecast of snow showers possibly throughout Sunday in the SE. Again it appears that UKMO are playing catchup; GFS last night were very close to their current 12z.

[danm]

Moved to Pompey from Essex over a decade ago, and look at Essex with envy now this weekend as looks like they will get plenty of snow! So what are the chances of Portsmouth getting at least a covering? Even just an inch will be great

*NEW* Weather-related puzzles now available on www.twitter.com/jumblgram

the only way is essex

[SnOwFeSt]

This is knife edge stuff, but i would expect upgrades as nowcasting kicks in. The latest outputs are showing the mild sector being mixed out so sub zero 850 air remains as the front passes through. With such deep surface cold, you'd fancy that would be sufficient to maintain snow. We'll find out tomorrow I guess!

ps: what time is the front due to hit west yorkshire? I've heard it may be saturday afternoon/evening, but does anyone have a more accurate time when it will start. I am due to be driving on the motorway at about 5pm, so wondering whether it will be heavy then?

[guvnor22002]

in the northwest region thread people have noticed the amber warning has been shifted about 30 miles west but on met site they have not mentioned they have updated it but its deffo moved west.

[Roger J Smith]

Be optimistic, this is a very weak push of milder air running up against entrenched low dew-point arctic air that will only yield near the southwest coast, otherwise, it will remain in place and outlast the mild air which will be lifted and then obliterated by the steady weakening of the initial front, to be replaced by a new energy centre within the decaying remnants Saturday night (around the mid-Channel). That new centre will have no mild air left and will reactivate the snowfall over the southeast.

My estimates for total snowfall amounts would be generally 10-20 cms with potential for local 20-30 cms in almost all of the eastern half of the UK and 5-15 cms over higher parts of Wales and southwest England, Midlands, 3-7 cms in northwest England where an earlier end and changeover to sleet or freezing drizzle will lower amounts. The snowfall may continue with 5-10 cms more on Sunday in the southeast.

Prospects for next week seem to depend on which of two model camps succeeds, but would not be surprised if there's a reload for southeast England at least around Tuesday-Wednesday.

Getting back to the Saturday event, the only places likely to see rain would be around the southwest within 300m of sea level, and even there it could start as snow and change back to snow near the end, so an elevation-dependent snow pattern is likely. In the Thames valley, the snow may become wet, mix with sleet or ice, then turn back to powder snow in a later stage. This will make roads in south central and inland southwest very icy as weekend traffic compacts the snow and mixed precip adds an icy layer to that. Road issues further east are more likely to be snow clearance but hills may become very icy again because weekend traffic loads tend to be evenly distributed rather than rush hour dependent, so that conditions will be treatable at all times which will encourage traffic rather than just making for gridlock-induced untreated but undriven roads if you see what I mean -- the net result could be very dangerous road conditions and I doubt that more than 10% of the vehicles that go out on the roads will have winter tyres so watch out for gooners sliding sideways or doing complete 180s as they see drivable roads and figure that means drive at speed limit. I base that on similar snowfall types and driving skills in my part of the world which is also hilly and sees snow infrequently with only minimal infrastructure to clear the roads in larger storms. Once saw a guy come out of an underground parking garage onto a slick pavement after about an inch of snow that had frozen, and he got about as far as the next building before doing two complete revolutions into a lamp-post. Some people just don't get the concept of slowing down, do they?

Anyway, good luck all you snow fans, I think your number has finally been drawn this winter, unless you're in Plymouth or Exeter.

[The PIT]

I've noticed our council has gone grit crazy already. I wasn't surprised though as every winter for the last ten years or so they only grit very lightly November December and Jan and then the amount goes up. I wonder if they have to use the stocks each year and if they don't the budget is cut.

Anyway looking forward to first proper snow event of the winter. Hopefully we won't return to the none events of the rest of the 2000's where mild air has pushed in very quickly indeed faster and further than expected meaning just a slight dusting before rain sets in. Sunday morning I want to see four or five inches sitting there.

[Essan]

I suppose they're gritting now to build up supplies on the road surface prior to tomorrow? Too dry atm for ice to form on most roads.

[TEITS]

Only just had opportunity to view the 12Zs and it appears the NAE did trend slightly further W compared to the 06Z. Based on all my years of following the models the NAE has often been the most accurate at this timeframe.

This seems a fairly accurate prediction.

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2012/02/03/basis12/ukuk/weas/12020512_0312.gif

Snowfall amounts appear to favour locations such as Lincs, Norfolk.

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2012/02/03/basis12/ukuk/rsum/12020512_0312.gif

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2012/02/03/basis12/ukuk/weas/12020506_0312.gif

Front has moved further E compared to this morning/yesterday and is now centred across Norfolk-Kent.

http://nwstatic.co.uk/fax/PPVI89.png

However please take into account that even on the day itself the front might be slower and progress slightly less E than what the models suggest. So if you're living in the E midlands/E Anglia/SE not only do you need to follow the snow on the radar arriving in your region but keep on eye on the front slowing.

[SMU]

Does the ukmo affect your snow line Steve

Or does it stay pretty much the same

Yes UKMO spreads in west around 50 miles

S

[SMU]

Dave looking at the NAE depths you would say it schould be scaled according to the bottom- however that looks to low-

what do you think they are?

S

[Stuie]

TEITS fingers crossed then mate, I am just sw of cambs.

[If Wishes made Weather]

"I doubt that more than 10% of the vehicles that go out on the roads will have winter tyres"

Roger - this is the UK, you missed the decimal point - almost no one has winter tyres. Since we drive in Germany we run winter tyres November onwards (175 width tyre with a different tread). The compound is softer and from temperatures of +7c and below the stopping distance is significantly reduced (we run 225 width tyres in summer). The push for this came from the insurance industry in Germany. Much safer snow or no snow.

As far as depths tomorrow are concerned, we are being consistantly progged for circa 15 mm precip tomorrow, so circa 20 cm for East Herts.