Significant Snow Risk This Weekend - General Discussion

[Heisenberg]

Hi,

Any chance for the snow settling in London tmr night?

I would say yes. Judging by the surface temps and the amount possible it could settle, but being london, Im not sure it will last too long. The centre of town generally gets a few degrees warmer than the outer subs.....

[liam300]

I would say yes. Judging by the surface temps and the amount possible it could settle, but being london, Im not sure it will last too long. The centre of town generally gets a few degrees warmer than the outer subs.....

Haven't got no chance in the Portsmouth area then

[LeeSnowFan]

Afternoon All,

Certainly looking like a "White Out" tomorrow and into Sunday for many people,

Wonder if anyone can clarify the snow risk for South Yorkshire , especially my area Barnsley are we looking at another 2010? is it worth me buying a sledge I have one on reserve lol

[liam300]

Take it everybody has given up on the current models / forecast for snow then?

[Aaron]

Anyone remember, after the December 2010 cold had finished, there was heavy snow forecast a few days later.. temps were around 1C but it just rained and rained.. I'm being extra cautious this time around

[johnholmes]

Afternoon All,

Certainly looking like a "White Out" tomorrow and into Sunday for many people,

Wonder if anyone can clarify the snow risk for South Yorkshire , especially my area Barnsley are we looking at another 2010? is it worth me buying a sledge I have one on reserve lol

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.

[MR EXTREMES]

Take it everybody has given up on the current models / forecast for snow then?

i would keep watch theres a strong possibilty snow will fall here in portsmouth!

But likely to turn to sleet but also possible it wont rain.

I think having a southerly or se flow will still have cold uppers in the mix but how much the sea temps effect the upper and ground level air could be a problem.

But im sure were see something wintry.

[kold weather]

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.

Thats where I'm not sure I agree John, the profiles for both the temps and the dew points are probably about 1C higher than they were compared to yesterdays runs. It won't stop snow falling but it MAY have an effect on the backend of the front and where as before much of the east may have gotten away with a pure snow event, there is a much higher risk of it turning to sleet/rain at the back end due to those slightly higher profiles.

Most of central and eastern areas will see a solid couple of hours of snow, with that time period increasing the further E/SE you go.

12z NAE will be interesting, and in fact the 12z suite in general is key.

[johnholmes]

Thats where I'm not sure I agree John, the profiles for both the temps and the dew points are probably about 1C higher than they were compared to yesterdays runs. It won't stop snow falling but it MAY have an effect on the backend of the front and where as before much of the east may have gotten away with a pure snow event, there is a much higher risk of it turning to sleet/rain at the back end due to those slightly higher profiles.

Most of central and eastern areas will see a solid couple of hours of snow, with that time period increasing the further E/SE you go.

12z NAE will be interesting, and in fact the 12z suite in general is key.

I wont argue with what you say as I have not done anything other than a quick skim through the 06z output.

[IDO]

Liam Dutton's Blog suggests the front is going to grind to a halt in the middle of the UK:

http://blogs.channel4.com/liam-dutton-on-weather/snow/494

I suspect that means more potential for the cold to stay in the East, limiting the thaw, or the snow turning to rain. All still up in the air.

[EML Network]

Liam Dutton's Blog suggests the front is going to grind to a halt in the middle of the UK:

http://blogs.channel...eather/snow/494

I suspect that means more potential for the cold to stay in the East, limiting the thaw, or the snow turning to rain. All still up in the air.

That's good news for everyone in the East and South East IMO, if the front stalls , then to the East and SE there's a better chance of having an all snow event, especially seeing as the rainfall is likely to be on the back side of this front as it passes through, the saga continues, but IMO that's good news for those in the East and South East

Edited February 3, 2012 by EML Network

[Snowmaggedon]

How much snow is likely to fall in Middlesbrough? The Met Office has given Middlesbrough a yellow warning, but the 5 day forecast states heavy snow on Saturday evening and light snow during the night...

[Eskimo]

How much snow is likely to fall in Middlesbrough? The Met Office has given Middlesbrough a yellow warning, but the 5 day forecast states heavy snow on Saturday evening and light snow during the night...

My guess would be up to 5cm for your area, not an extreme amount by any means but it is something.

[No Balls Like Snow Balls]

How much snow is likely to fall in Middlesbrough? The Met Office has given Middlesbrough a yellow warning, but the 5 day forecast states heavy snow on Saturday evening and light snow during the night...

IMO 35-45 cms :winky:

[johnholmes]

This is the Guide I prepared quite some time ago; using the 06z output from Net Wx Extra and for Doncaster, almost sea level and the area that seems most under threat FOR ONCE of snow, let’s see how it stacks up?

Values in red after each element; well its was until I posted it in here but I think its fairly obvious where I've put data in?

Precip forecast from about 15z and 8mm by 03z Sunday

1. Dry bulb temperature below 5C, often 3C is a better mark temps=2,2,,-1,-0,-1 whilst precipitating
   

2) Dewpoint at or below zero=

yes

3) wet bulb temperature, if you have a weather station, no more than about 2C

=I calculate well below 2C

4) 1000-500mb thickness (DAM) less than 522dm, lower if you are on the coast, but as high as 540dm it is possible in a heavy shower, but unlikely.

above 528DM until 00z then

below

5) 850mb temperature of -7C or below, -5C it can occur but not often

.-2C until 00z then -4C

6) on the 850mb chart if the value shown on the contour line is below about 1290dm or 1300dm, then there is a high chance that ppn will be of snow.

Around 1290DM-hard to be precise on the Atlantic chart

(The Met Office use 1293dm for a 50% and 1281dm as a 90% chance of snow)

7) zero degree isotherm or freezing level of 1,000ft or less to give a 50% or higher chance of snow

at sea level.

At or near sea level throughout but milder air is quite close to W/SW

The higher you are the higher the chance of you getting snow. Thus if you live at 2000ft this increases your chances of snow considerably to someone at sea level.

At sea level or close throughout, milder air close by

I’m not using the frontal types do to time constraints.

My estimation using the above, and it partly supports what Kold posted, is that it will be a sleety mix at first soon turning to snow with 2-5cm falling in the Doncaster area, possibly 4-7cm on the higher areas by the M18 towards Rotherham(Potty!!)

A slow thaw from mid am onwards until evening.

just a very quick idea using Doncaster and the 06z output, try it for your area, and with each run if you wish to see how it may change?

good fun too.

Edited February 3, 2012 by johnholmes

[Snowmaggedon]

Maybe if the town was located right in the middle of Serbia lol

[Heisenberg]

How much snow is likely to fall in Middlesbrough? The Met Office has given Middlesbrough a yellow warning, but the 5 day forecast states heavy snow on Saturday evening and light snow during the night...

Probably better to ask in the regional threads, but the 5 day forecast is just a computer generated forecast....watch the warnings, they have the human input....

[MKN]

Nae at +30 further west?

[IDO]

US Air Force model:

https://afweather.afwa.af.mil/public_images/MEURSFCSNTT048.GIF

(Notty...theweatheroutlook, Thanks)

NAE:

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2012/02/03/basis06/ukuk/weas/12020506_0306.gif

Both suggest south missing out apart from far south east.

May still change.

Edited February 3, 2012 by i'm dreaming of...

[kold weather]

Not so much further west, but it IS slightly slower in its forward motion which is a good thing for most people as it allows the snow to get going just as the sun goes down. You'd be surprised how much of an advantage the night time can be in these sitautions, I often find for marginal areas that the difference between snow and rain.

[john mac]

Not so much further west, but it IS slightly slower in its forward motion which is a good thing for most people as it allows the snow to get going just as the sun goes down. You'd be surprised how much of an advantage the night time can be in these sitautions, I often find for marginal areas that the difference between snow and rain.

Any chance of us getting higher totals as its moving slower ?

[SMU]

well here we go-

the 12s in mid flight already- the GFS was amplifed at a better angle at 18- should mean better pickings for everyone...

S

[Heisenberg]

So the slower movement?? does that make any difference to us in the SE, or are we still set to get it, just later on in the night?

Edited February 3, 2012 by lloydyd

[SMU]

Oh dear. I think the swear filters will be in overdrive with the latest models. Seems to be shifting west...

after the 06z pretty much everyone wants it west-

S

[snowwizard]

what the chance of snow in south cambridgeshire tomorrow night and how much if snow arrives

what the chance of snow in south cambridgeshire tomorrow night and how much if snow arrives

what the chance of snow in south cambridgeshire tomorrow night and how much if snow arrives

what the chance of snow in south cambridgeshire tomorrow night and how much if snow arrives