Wales (cymru) - Regional Weather Discussion (part 3)

[WalsallWeather]

Latest NAE...

As it stands, I think that snow'll turn pretty quickly back to rain, away from the mountains...

As others have said- time for changes yet.

The latest NAE is better and it's encouraging that with each model, it's bringing a little more hope our way!

I agree that that snow would probably turn back into rain but lets hope the encouraging models continue.

EDIT: MetO weather warnings are working again, and yes they have been updated for Wales as someone said. Most of us have a weather warning of snow. Still not getting excited by it!

Edited February 2, 2012 by CarmarthenshireWeather

[TonyH]

As it stands for most of us this will be a transient snow event Saturday, although those of us high up like Andy should have a covering.

Two points look at the isobars on the charts posted above they show milder sw winds over Wales, plus pressure is 1030. These suggest to me fairly light precipitation and brief snow to damp and drizzly conditions.

It could stay cold enough for a snow cover to form and stick above 300m but it does look like less cold weather for all on Sunday and Monday.

[benb]

However as posted in the Model thread from the GEM we have this showing there is a chance it could stay mostly as snow if it came off!! (how likely this is i am not sure)

You pays yer money-

Very transient affair still predicted on GFS, with widespread low-land snowfall reserved for east of the border...

Still 48hrs to go- certainly time for a change.

As someone else has stated- met office warnings may well be to cover their backsides in case the area of snowfall is shifted further west.

Edited February 2, 2012 by benb

[benb]

As it stands for most of us this will be a transient snow event Saturday, although those of us high up like Andy should have a covering.

Two points look at the isobars on the charts posted above they show milder sw winds over Wales, plus pressure is 1030. These suggest to me fairly light precipitation and brief snow to damp and drizzly conditions.

It could stay cold enough for a snow cover to form and stick above 300m but it does look like less cold weather for all on Sunday and Monday.

Agreed.

I think we need one of two things to happen for extensive, prolonged snow on Saturday:

1) The block/ deeper cold air to shift further westwards between now and the front arriving, so the front stalls over us on the boundary of the cold/warm air, meaning the warm air never reaches us to turn the snow to rain.

or

2) There's a change in the synoptics i.e the front approaches from a more favourable direction and doesn't displace the cold air so quickly or a short wave develops, heads in a SEerly direction, pulling in the very cold air to the east, behind it.

Happy to stand corrected on those!

[CLH the red dragon]

850's are looking good though, -10's on both the UKMO and GEM models.

Edited February 2, 2012 by CLH the red dragon

[Buzz]

As it stands for most of us this will be a transient snow event Saturday, although those of us high up like Andy should have a covering.

Two points look at the isobars on the charts posted above they show milder sw winds over Wales, plus pressure is 1030. These suggest to me fairly light precipitation and brief snow to damp and drizzly conditions.

It could stay cold enough for a snow cover to form and stick above 300m but it does look like less cold weather for all on Sunday and Monday.

Agreed on all points.

[nwales]

Trying not to get excited about the prospect of snow after being disappointed last weekend... The outlook from the met office suggests there will be snow on high ground in Wales into next week - we'll see!

Last night was a very cold one, the min here was -7.1c Max today of 0.1c

Current temp: -0.7c with a lot of cloud.

[TonyH]

With tonight and tomorrow looking the peak cold period it might be of interest to track temperatures.

Currently -4c here.

It was -6c this morning.

[mikeocarroll]

I think the weekend is still on a knife-edge, I've got know idea how it will go but I do think the next few days will be very exciting!

I agree with TonyH that precip probably won't be that heavy, but I'm not convinced that it will turn to rain that quickly, especially in eastern Wales.

And for the hills and mountains, they could start to build up some decent snow depths. The snowline is about 250m here at the moment, really nice to look out at snow-capped hills in all directions.

Not sure what temp it got to here last night as my weather station stopped sending data I think the batteries may have frozen? It went down to -7.0c a couple of weeks ago without any problem. Cloudy currently, -1.0c, max today was 0.7c.

[DeepSnow]

With clear skies here it is -0.4C currently, living in a town nearish to the coast I rarely see temperatures go below -4C, nov/dec 2010 being an exception to that! If we miss out on the weekend I hope we get something next week, with the cold looking to hang around for a while longer!

[Wales123098]

-3.2c here. Falling quickly. Im not very confident for the weekend..:/ However latest ECM does keep some coldish uppers over East Wales through the event, cold enough for snow I think? http://www.meteociel.fr/modeles/ecmwf.php?ech=72&mode=0&map=0&type=0&archive=0

Edited February 2, 2012 by Wales123098

[Snowmadsam]

-3.2c here. Falling quickly. Im not very confident for the weekend..:/ However latest ECM does keep some coldish uppers over East Wales through the event, cold enough for snow I think? http://www.meteociel...ype=0&archive=0

Me neither I will get snow then rain

[CLH the red dragon]

-3.2c here. Falling quickly. Im not very confident for the weekend..:/ However latest ECM does keep some coldish uppers over East Wales through the event, cold enough for snow I think? http://www.meteociel...ype=0&archive=0

As I said above, both the UKMO and GEM have Wales under -10's. Which certainly is.

[Snowmadsam]

As I said above, both the UKMO and GEM have Wales under -10's. Which certainly is.

But don't DAM's have to be below 528? deffos think this is a no go now...

[Buzz]

But don't DAM's have to be below 528? deffos think this is a no go now...

The 528 line is just a 'guide' - it's not essential to provide snow. There are assorted variables in the mix, and the 528 line is just one of them. However, the lower the better.

[benb]

60hr Fax chart, Sunday, projects the front just east of the border, but, as I alluded to earlier, it now looks like it may start buckling back westwards, as the shortwave heads southwards across the channel.

Edited February 2, 2012 by benb

[DeepSnow]

So would the latest fax chart increast our chances of this being a mostly snow event for Wales?

[Snowmadsam]

60hr Fax chart, Sunday, projects the front just east of the border, but, as I alluded to earlier, it now looks like it may start buckling back westwards, as the shortwave heads southwards across the channel.

[Daniel Miller]

Ooh.. Going by the FAX and the fact we may have colder uppers in place when the front arrives, is it possible when it passes us it is snow, and if it turns back to us that it's snow?

[Buzz]

That's certainly a very positive sign.

[willitbsunny]

Derek Brockway's forecast on BBC Wales just showed a mainly rain event....

[benb]

So would the latest fax chart increast our chances of this being a mostly snow event for Wales?

I think I'm correct in saying, ideally, for widespread, low-level snow, we'd want that shortwave feature to develop further- to be come 'closed'- a complete circulation. This would result in colder uppers (and lowers!) being pulled back west after it- thus possibly turning any rain back to snow.

It would also increase the chance of snow to start with, as the front wouldn't be 'challenging' the cold air head on, more likely to be sliding off to the S/SE, thus not displacing so much of the cold air.

That chart doesn't quite show that- but it hints at what may (or may not!) happen!

It's all speculation at this stage, anyhow!

Edited February 2, 2012 by benb

[Marcus_surfer]

Not really looking forward to this. Snow to rain events suck!

[Cheshire Freeze]

Derek Brockway's forecast on BBC Wales just showed a mainly rain event....

These are 12z trends I don't think the visuals are altered until after the evening broadcasts (on some occasions)

[andymusic]

Derek finds these types of events really challenging for some reason - although I think most of the pro forecasters really have a tough time with an event of this nature with temps on a knife edge! - it'll be a sort of now cast event in the end - we will all be on the edge of our seats seeing what exactly will transpire. Mind you the "trying to guess what it'll be" leading up to it is a lot of fun too! - I'm going for more snow than Derek is going for over Wales - we'll soon see whose right and not so eh!