wales Wales (Cymru) Regional Discussion 24th January 2013, 06z onwards

[andymusic]

THIS IS ONLY THE BEGINNING OF AT LEAST A TWO WEEK ONSLAUGHT OF SNOW AND BLIZZARDS - BE WARNED!

Edited February 4, 2013 by andymusic

[bradymk]

THIS IS ONLY THE BEGINNING OF AT LEAST A TWO WEEK ONSLAUGHT OF SNOW AND BLIZZARDS - BE WARNED!

Hardly a two week onslaught, as much as i love your posts, we dont want to confuse people. What we have over the next few days is just a cold NW flow, colder than most NW flows but nothing extreme. No MetO warning for us and it will depend on time of day/altitude whether you see accumulating snow. After the end of the week, still open to date but it may become colder and the snow potential increases but a 2 week onslaught of snow and blizzards are unlikely. (secretly hoping you are right)

[mikeocarroll]

Well today, or most likely tonight, is the first of several days (and potentially longer) when we have a chance of seeing something wintry.

Colder uppers will gradually move in during the day and by tonight uppers and thicknesses will be sufficient for snow. Looks like plenty of pecip this evening according to NMM - this shows the formation of an organised band of precip over North Wales, perhaps associated with a trough or front (I've not checked the FAX) that moves south overnight.

I think the biggest interest is whether surface temps, dewpoints and wet bulb freezing level will be low enough, today and through the next few days. As you can see dewpoints are forecast to be above freezing this evening for all of Wales, although these will cool through the night and also during moderate or heavy precipitation:

It's going to be a case of looking out the window, and also checking the thermometer! It will get colder as the night goes on but then tomorrow the warmer air will move down, bringing some frontal precipitation but this will only be wintry over high ground I think, unless temps end up much colder than forecast. Later tomorrow night into Wednesday morning the cold upper air returns and with it the prospect of snow showers, but it depends how quickly the cold air digs back in and how long the flow remains west or north rather than a straight northerly (which would be drier for Wales).

Looking further ahead and still disagreement this morning in the medium term with the GFS not quite playing ball with the ECM (and to an extent the UKMO) which bring a slider low and snow potential next weekend. But in the longer term the outlook is cool to cold the 0z GFS ensembles are very encouraging IMO as even if the GFS is correct about a warmup next weekend (and for what it is worth I think it's wrong) there are plenty of cold prospects in the longer term with the mean upper temp close to -5c throughout:

Temperature here currently is 7.4c and still edging up. Perhaps a little higher than forecast so I hope this is close to the maximum and it starts declining soon - it's got a long way to go to be viable for snow.

[Marcus_surfer]

So western wales not even in the ice warning put out by metoffice. Odd that in a northwesterly western areas do best and highest ground looks like it could get some lying snow by morning.

[Bobby]

Well today, or most likely tonight, is the first of several days (and potentially longer) when we have a chance of seeing something wintry.

Looking further ahead and still disagreement this morning in the medium term with the GFS not quite playing ball with the ECM (and to an extent the UKMO) which bring a slider low and snow potential next weekend. But in the longer term the outlook is cool to cold the 0z GFS ensembles are very encouraging IMO as even if the GFS is correct about a warmup next weekend (and for what it is worth I think it's wrong) there are plenty of cold prospects in the longer term with the mean upper temp close to -5c throughout:

Quite, I don't think tonight/tomorrow is the last of the snow potential, if that slider low if it comes off right like UKMO and ECM been hinting at that could give us a snowfall similar to the big one we had in Jan and even the GFS 06z which doesn't show much of a slider still has a potentially snowy cold setup at day 7.

Uppers

Also in my experience we often do better out of NW/lies, N/lies here than forecasts have predicted (at least IMBY), I can remember several times we've had unforecast decent falls from setups like this. I'm sure almost all of us will see falling snow but a lottery as to how much falls, but I think some of us will get a decent fall of snow tonight/tomorrow.

Best just to look out of the window and see what's happening in these setups, they can be fun at least!

Get those lamposts revved up and ready to go.

Edited February 4, 2013 by Bobby

[freeze for all]

Very Light snow shower in Tonyrefail apparently!

[mikeocarroll]

Temp up to 7.8c now... come on cold... where are you? (answer: not forecast to arrive until later, I'm just impatient)

[TonyH]

Very Light snow shower in Tonyrefail apparently!

No chance way too mild

[TonyH]

Judging by the warnings this will most likely be a high ground only event tonight and tomorrow for significant accumulations, I would never have expected proper accumulation below about 200m nice to proved wrong though.

[Marcus_surfer]

Temperature has a Long way to go to get any snow currently 6.8 Celsius

would need about two or three Celsius with dewpoints below zero For any snowfall which hopefully will happen later this evening

[derrylynne]

Very Light snow shower in Tonyrefail apparently!

No way. I live about three miles from Tonyrefail and it is far too warm with dew points too warm also. Wishful thinking Butt.

[loadsa]

latest off Derek

Derek Brockwayâ€@DerekTheWeather

Keep an eye on the latest warnings on the @MetOffice website. Just an ICE warning in force at the moment for #Wales http://www.metoffice.gov.uk/weather/uk/wl/wl_forecast_warnings.html …

also

Derek Brockwayâ€@DerekTheWeather

Weather map Tuesday 6am. Snow shown in blue. 1 to 2cm away from the coast. 5cm or more on some hills & mountains #Wales pic.twitter.com/Dc0jKgn7

[andymusic]

[keithlucky]

Snowing in central Ireland blizzard conditions temps drop from 3c to 0 c in the showers.

[Bobby]

I wouldn't worry about the temps too much, I remember during Northerlies in the past the temp being 7-8c at times and it still snowing with the temperature plummeting under any showers, sometimes down to 2-3c in a few minutes, the heavier and more prolonged the better. Looks marginal though at times for lower ground and coastal areas and I'd agree with most settling snow probably above 150-200m or so.

Some streamers and more organised stuff from troughs would be most welcome please.

[mikeocarroll]

Snowing in central Ireland blizzard conditions temps drop from 3c to 0 c in the showers.

That's encouraging Keith. 12z NMM delays coldest air by a couple of hours, midnight, 1am onwards looks like our best chance of snow. Think tonight looks better than tomorrow night, less precip but dewpoints more favourable.

Temp here currently 5.8c, falling steadily (as you would expect at dusk). Some hail showers have passed through. Low humidity, dew point 1.5c which is encouraging.

[andymusic]

Snowing in central Ireland blizzard conditions temps drop from 3c to 0 c in the showers.

feels bitter outside already up with me - so - here we go again! - Are you all ready?

[Stevetynant]

still 7C here

[dyl232]

What is the chances of snow sticking to low levels in nw wales tonite?

[TonyH]

Hmm not hopeful with this one, temperature rising here 6.0c. Can't imagine any snow that falls will have a chance of settling.

[CLH the red dragon]

Pretty mild feeling IMO, nothing like last time.

[foggybrynna]

Andy snow getting as far as us ponty - talbot green doz your charts say diff

[keithlucky]

Hmm not hopeful with this one, temperature rising here 6.0c. Can't imagine any snow that falls will have a chance of settling.

Better chance than us Tony the cold sector reaches you before midnight temps should drop to around 2c.Really impressive showers now growing across Ireland smack on course for N West Wales. Edited February 4, 2013 by keithlucky

[mikeocarroll]

Hmm not hopeful with this one, temperature rising here 6.0c. Can't imagine any snow that falls will have a chance of settling.

Temp has risen here too, 5.9c currently. Not too despondent though as temps can fall rapidly when they have a mind to, and the early hours of tomorrow morning are when our chances of snow will be greatest.

Precip is a bit strange, the blob over me right now (falling as rain/hail mix) came out of nowhere about half an hour ago and has steadily intensified, while moving slowly eastwards. It's rare for showers to form this far inland, usually they form out to sea and move inland, so a good sign as far as I'm concerned.

[J10]

On the evening of the 16th Jan, people were on this thread saying it is too mild, no snow and moaning generally look what happened then.

The low thicknesses are not here yet, temps will fall, dewpoints are set to be well below freezing aorund 6am.

The thicknesses are less marginal than other snow streamer events which have given large snowfalls.

This is the latest Met Office warning.

This Evening and Tonight:

Frequent showers moving south this evening, these turning increasingly wintry to all levels overnight with a slight covering of snow possible in places. Feeling very cold in the strong to gale force westerly wind with icy patches developing inland. Minimum Temperature -3 °C.

Tuesday:

Bright spells and frequent wintry showers giving some snowfalls over higher ground. Showers turning to rain at lower-levels later. Very windy, especially around the showers with coastal gales. Very cold. Maximum Temperature 8 °C.

Some places will see snowfalls others will not, in one of my regular updates for this a few days, I did mention that temps are likely to be above freezing and this may well hinder settling snow, and this is an issue tomorrow, heavy showers falling between 6am and 9am are most likely to settle and a lot depends on where this happens.

Due to the WNW flow, eastern areas are likely to do better than a in a straight NNW, in which I would be more expectant, with these synoptic rather than just hopeful.

Edited February 4, 2013 by Jackone