Wales Cymru Regional Discussion - January 15th 2013>

[WalsallWeather]

Great developments by the sounds of things! I still worry that I will see rain or sleet! Hopefully it'll be snow. Any idea what time snow is set to begin (if we get the snow that is!)

Also, how icy was it today? I am between Llanelli and Carmarthen and this morning going to work at 6am it was really bad, I know of two people who crashed between 6-8am because of it, also my dad lost control of his car too! Thankfully everybody is okay but it was really bad out there!

[mikeocarroll]

Agree 12z GFS shows an all-day snow event for most of Wales on Friday, and some significant totals possible as posted above, possible reloads Sunday and Monday. Only not looking too good for Pembrokeshire at the moment but as well all know much can change and with about 60 hours still to go there aill no doubt be downgrades for some of us and upgrades for others.

[Panayiotis]

Yes 12z is amazingly better than the 06z and the cold is still with us in a weeks time, with an easterly bringing in those cold uppers, looks good!

Edited January 15, 2013 by Panayiotis

[dbaloo]

As im still a newbie here, could i ask.... as we are now 24 hours closer to friday than we were yesterday,should we take this 12z run as the start of "confirmation" of whats to come or do we wait until 24hrs b4?i know that might sound like a daft question but im learning

[WalsallWeather]

As im still a newbie here, could i ask.... as we are now 24 hours closer to friday than we were yesterday,should we take this 12z run as the start of "confirmation" of whats to come or do we wait until 24hrs b4?i know that might sound like a daft question but im learning

I'm no expert but when it comes to snow I wouldn't take anything as confirmation until you actually see it falling outside! A very tricky weather to forecast!

[Panayiotis]

As im still a newbie here, could i ask.... as we are now 24 hours closer to friday than we were yesterday,should we take this 12z run as the start of "confirmation" of whats to come or do we wait until 24hrs b4?i know that might sound like a daft question but im learning

No tomorrow evening's 12z will give us a much better understanding with whats happening Friday but its looking more likely, that most in Wales will see snow (but details of how heavy and duration etc is unknown), ill try and keep you updated. Edited January 15, 2013 by Panayiotis

[bradymk]

Agree 12z GFS shows an all-day snow event for most of Wales on Friday, and some significant totals possible as posted above, possible reloads Sunday and Monday. Only not looking too good for Pembrokeshire at the moment but as well all know much can change and with about 60 hours still to go there aill no doubt be downgrades for some of us and upgrades for others.

Disagree with Pembs, 12z way better than 6z. Only reason GFS doesnt show snow hatch lines or snow risk as high over us is simply because it overestimates the temperatures on the coast. It may turn to rain here quickest (if it does at all) but 12z much better for seeing at least some snow friday, im happy with that anyway,

[dbaloo]

Would just like to say thanks to

CarmarthenshireWeather and Panayiotis

for their reply's. I shall await tomorrows run with great expectation!.

[Ginkrots]

Garden thermometer (albeit a cheap basic one) showing -2 already in Newport, it's going to be a chilly one for inland areas tonight!

[matty lfc]

This time tomorrow we MAY have a fairly good idea of snow on Friday but until then it's still nigh on impossible to be confident in any forecast given the complex models at the moment.

As someone pointed out,it's a fine line between 6 hours of wet snow not accounting to much or 6 hours of "proper" snow dumping 30cm on some of us.

I'm urging caution and not to build hopes up.

[mikeocarroll]

Disagree with Pembs, 12z way better than 6z. Only reason GFS doesnt show snow hatch lines or snow risk as high over us is simply because it overestimates the temperatures on the coast. It may turn to rain here quickest (if it does at all) but 12z much better for seeing at least some snow friday, im happy with that anyway,

I think you're right in terms of starting as snow but Pembs is at higher risk of turning to rain relatively quickly, at least in the western edge of Pembs, if you see the 850hpa temps around 0 to -1c:

The dewpoints range from 0c to 4c over a very small area:

Wet bulb temps are above freezing:

I would say from the above marginal for lying snow in Pembs, but a shift 30-40miles west and bingo!

[marclt]

Need to see some more blue over west Wales. There was no ice or frost anywhere west of Carmarthen it would seem this morning. An interesting drive east to work.

[welshgritter]

Fridays a long way away yet guys.

[bradymk]

I think you're right in terms of starting as snow but Pembs is at higher risk of turning to rain relatively quickly, at least in the western edge of Pembs, if you see the 850hpa temps around 0 to -1c:

The dewpoints range from 0c to 4c over a very small area:

Wet bulb temps are above freezing:

I would say from the above marginal for lying snow in Pembs, but a shift 30-40miles west and bingo!

Yes i would say according to GFS, it would be snow to rain for pembs atm. Uppers not so important but dew points and wbfl certainly important here and these increase quickly in Pembs. although like you say 20 to 40 mile shift and even the west coast will be in the fun and games. Still expect some more movements south and westwards so still game on. Praying the NAE had an off run, meto not using it however i will be worried if it shows the same in coming runs.

[Matty23]

what does it matter if NAE comes off?? wudnt iy just fizzle out get cold again ready for friday?

[jenko]

can anyone compare the charts to november/december 2009 to jan 2010? we had it really bad up here

[Panayiotis]

Temp down to 0C now, going to be one cold night!

[Ginkrots]

-3.5 in Newport and the grass is already frosting over - it's not even 6pm!

[Elnonio]

Nice to hear Derek talking about the famous Pembrokeshire dangler earlier! Oh and the blizzards he said were on the way of course

[J10]

Far too much looking in detail at charts 3 days away, they will change and in scenarios like this 50 miles is nothing.

Will do a brief summary of the big 4 after they all come out.

[J10]

Agree 12z GFS shows an all-day snow event for most of Wales on Friday, and some significant totals possible as posted above, possible reloads Sunday and Monday. Only not looking too good for Pembrokeshire at the moment but as well all know much can change and with about 60 hours still to go there aill no doubt be downgrades for some of us and upgrades for others.

Thanks for this pearl of wisdom, in today's desert.

[SnowStorm(Jamie)]

Just looking through some of the 12z data for Friday, if you ask me the Atlantic push seems to now be modelled a little further northwards, potentially allowing for more widespread snowfall across Wales/West Midlands however also introducing milder sectors into the SW of Wales.

I think what we have to look at here is where is the flow going to be coming from is it the SE/S/SW?

On Friday GFS shows a surface flow from the SE which is good in terms of keeping the low dew points as colder air is getting pulled across from Europe:

http://cdn.nwstatic....2/66/ukwind.png

But what about the upper flow? at the 850hpa level we see a flow from the South- more so originating from the Atlantic so this would also causing a rise in the upper air temperatures and in the past in these frontal situations your really looking for -1C and below:

http://expert-images...011806_1512.gif < Upper Flow

UKMO 12Z brings in more of a SE flow and the result is ahead of the front we have SE flow and colder air- brining snow to its northern edge:

http://www.meteociel...W60-7.GIF?15-18

Still its a case of watching the Models for trends northwards/southwards, upper temps, dew points, directional flow both upper and lower as we await it to come in range of the NAE. Expect Met Office warnings to be fine tuned as the days go on as details become more clear.

---

Just editing my post to include update on ECM 12Z

http://images.meteociel.fr/im/8773/ECM1-72_axh5.GIF < 72hrs

You can see how the atlantic push comes further North and East thus introducing slightly milder upper air over the SW/South Wales:

http://images.meteociel.fr/im/843/ECM0-72_wra7.GIF

So we have differences already but the GFS and ECM do seem to be somewhat similar to me in the shorter timeframe which i am focusing on at least.

Edited January 15, 2013 by SnowStorm(Jamie)

[TonyH]

Nice to hear Derek talking about the famous Pembrokeshire dangler earlier! Oh and the blizzards he said were on the way of course

Shame the dangler consisted of rain not snow though.

Edited January 15, 2013 by TonyH

[bradymk]

Still not to sure what to think of the event Friday yet based on latest fax and ECM. Going to need a few more runs here to see what happens.

[benb]

Well the mountain area forecasts for Friday and the weekend have upgraded for snow, from cold and dry to this-

http://www.metoffice.gov.uk/public/weather/mountain-forecast/#?tab=mountainDetailed&map=Mountains&zoom=5&lon=-4.00&lat=55.09&fcTime=1358317133

Would agree with previous posters that any snow over Pembrokeshire perhaps looks more transient than previously predicted as slightly higher uppers seem to move in quite quickly when the precipitation arrives- still looks great for further east though.

Could do with everything shifting 75 miles further west, for here, and that front sliding SSE rather than crashing directly W to E, I guess. But, who knows!

Temp 2.7c