Wales - Regional Weather Discussion

[kold weather]

Right here is another thread for you guys in Wales, keep us updated on this system on Thursday/Friday!!

[andymusic]

thunder and lightning and heavy snow here too now - was watching this one develop on radar!

Edited December 14, 2011 by andymusic

[Bobby]

thunder and lightning and heavy snow here too now - was watching this one develop on radar!

Crazy weather isn't it.

[andymusic]

Crazy weather isn't it.

seems to have got itself into a pattern of developing mini storms - one hit us literally this morning so hard it tripped all the electrics - frightened the life out of us - amazing

[Jackfrost]

Just had a half-hour long soft hail/snow shower which is failing to melt - turned icily cold now that the PPN has cleared. I can see the next clump of showers developing off the coast falling increasingly as snow inland.

[Phantom2]

temp 6.6c, wind 15.2mph, pressure 992.5 ...sky looks black out to the West, another hail storm on the way !

[Bobby]

Latest GFS for us looks fun

Going to be one of knife edge marginal set ups

The higher you are up the better

[DeepSnow]

Had heavy rain and hail showers all day, another massive black cloud coming in from the west! Though unlikely, would love to get some snow here end of the week/weekend!

[J10]

A real wintry mix day with rail, hail,sleet and snow, with temporary slushy accumulations at times (mainly of hail) temps around 3-4c

Very dark at times as well during the day.

[kold weather]

Marginal is indeed the word and as per normal even 100M of ground will make a difference. Models are quite keen on snow falling though for Wales, especially the northern area where precip is forecasted to be heaviest.

[andymusic]

Latest GFS for us looks fun

Going to be one of knife edge marginal set ups

The higher you are up the better

If the low tracks well for us then I see no reason why it won't be a snowfest running into friday

[DeepSnow]

If the low tracks well for us then I see no reason why it won't be a snowfest running into friday

I think, like in recent days, anywhere below 100M will more than likely miss out though?

[Stevetynant]

amazing day in Newport - was pitch black at 9:30 in the morning

[andymusic]

Latest from the Meto for Thursday night/Friday

To the north of the storm, colder air will bring a risk of snow to Wales and parts of central England from the early hours of Friday morning.

The snow is likely to accumulate even at low levels with the risk of up to 10 cm lying over higher ground.

Colder than average temperatures will then carry on through Friday and the weekend, continuing the risk of icy conditions.

Full press release here - http://www.metoffice.gov.uk/news/releases/archive/2011/wintry-and-unsettled

Edited December 14, 2011 by andymusic

[SnowStorm(Jamie)]

Interesting developments for the Thursday/Friday system with its more southerly track brining the risk of snow.

The NAE has shifted this low pressure system southwards somewhat when comparing the 0z against the 12Z:

http://expert-images...121600_1400.gif < 0z

http://expert-images...121600_1412.gif < 12z

The question here is will this trend continue? The further south the low is, the further south that boundary will be between the cold air to the north and the warmer air wrapped around & to the south of the low- This gives snow chances on its northern most flank & also as it runs eastwards with colder air undercuting and possibly turning precipitation to snow.

Colder upper air and thickness (sub 528DAM) does come down from the north as the low runs eastwards as seen on the NAE:

http://expert-images...121606_1412.gif < Upper air temps

http://expert-images...121606_1412.gif <Thickness

GFS for the same time:

http://www.wetterzen...cs/Rmgfs422.gif < Upper air temps

http://hw.nwstatic.c...hgt500-1000.png < Thickness

UKMO:

http://www.meteociel...U42-7.GIF?14-17 < Upper air temps

http://www.meteociel...2-594.GIF?14-17 < Precipitation

Check out todays Met Office video on the situation: http://www.metoffice...y-and-unsettled

That video shows one of the the high resolution models that the Met Office uses with the rain/snow discrimination chart- looking at that most of the snow is over Northern, Central/East Wales & into the Midlands. Which is in line with the NAE and GFS - perhaps with the GFS brining the snow risk slightly further Southeast though.

[mikeocarroll]

Thanks Jamie I really appreciate the time you put into these posts... that goes for all the others who take the time to put in all the links etc - there are some really good posters in this forum.

Looks like uppers and thicknesses are steadily upgrading for Thurs/Fri night as the low is projected to track further south than was previously projected. Should be exciting tomorrow night.

[keithlucky]

What helps as well Jamie is the time of the precipitation (after dark) and heavy rain forcing the dew point down,so even at low levels sleet should turn to snow,plus Saturday -Sunday hopefully more snow showers move in from the North West,so lots to look forward to over the next 3 days.

[DeepSnow]

Not looking bad for Wales friday away from the coast!

[Jayfromcardiff]

Will it snow here tomorrow night? I can see this being a high ground event:(

[keithlucky]

Will it snow here tomorrow night? I can see this being a high ground event:(

Just for you blue bird read the last bit lol from ian fergeson via the met YELLOW EARLY WARNING of SNOW

Rain will turn readily to snow across many parts of the Midlands, Wales and southern England during the early hours of Friday morning, leading to a risk of disruption during the morning travel period.

Valid from 0005 until 1000 Friday Even snow in southern England.

[SnowStorm(Jamie)]

Thanks Jamie I really appreciate the time you put into these posts... that goes for all the others who take the time to put in all the links etc - there are some really good posters in this forum.

Thanks Mike i enjoy doing it & I agree there are some great posts on this forum.

What helps as well Jamie is the time of the precipitation (after dark) and heavy rain forcing the dew point down,so even at low levels sleet should turn to snow,plus Saturday -Sunday hopefully more snow showers move in from the North West,so lots to look forward to over the next 3 days.

Yup evaporative cooling could happen under constant heavy precipitation also. The exact track of the low is still uncertain at this point, so details on the rain/snow boundary will be changing from run to run.

[DeepSnow]

Out of curiosity, what would it take for more of south wales to see snow from this?

[J10]

The snow potential for Thursday night is greater than before, with higher ground in the South Wales Valleys looking favoured .However there is one consideration, that most places will see rain to start, and as such any snow that does fall is less likely to stick. Areas close to coast especially in western areas may well miss out on any snow, despite the wind direction turning round to a N/NE to finish.

However the NW flow after this although marginal has much better thicknesses than the attempts a week or so ago.

NMM Snow prediction 10pm

NMM Snow prediction 12pm

As you can see as time pushes on the snow levels become more extensive to the south, the 12pm chart is as far as this goes out. the 18hz run will do another 6 hours ahead.

Another thing to bear in mind with these types of scenarios is does your area do well out of them, and to factor this into your local snow prediction. .

[welshwizard]

by the look ov the map,it will miss most of southern wales,again below the m4. for some reason the m4 becomes a snow stopper quite a lot ov the time. i also think it will be a high ground event or more northern.Bridgend norm miss out in this sort ov snow and valleys seem to do ok.

[MKN]

The snow potential for Thursday night is greater than before, with higher ground in the South Wales Valleys looking favoured .However there is one consideration, that most places will see rain to start, and as such any snow that does fall is less likely to stick. Areas close to coast especially in western areas may well miss out on any snow, despite the wind direction turning round to a N/NE to finish.

However the NW flow after this although marginal has much better thicknesses than the attempts a week or so ago.

Rain to start will probably result in snow sticking quicker on road surfaces as any gritting done will be washed away which will probably mean, most roads wont be gritted to begin with, hence i think travel problems rush hour friday will be highly likely. We could however have done with a couple of harsh frosts to cool the ground temps before hand which would have helped