Wales Cymru Cold Spell Regional Discussion

[Bobby]

Can we get the cold air in place quick enough for snow in S Wales on Saturday that is the question?

Upper air temps for 12pm Saturday are -4c to -6c for most - should be good enough for snow.

Won't know the details for a while yet though.

Edited January 8, 2013 by Bobby

[mikeocarroll]

Yep models showing a potential snowfest for Wales, on Sat/Sun/Mon, could be epic and well worth waiting for. I'm a bit nervous though as the models couldn't really get any better, so downgrades are likely (the best case scenario is that the models stay exactly as there are). It's a bit like if your horse is winning the race with two fences still to jump, sometimes you feel more confident if your horse is running a close second. Still I think the mild horse is well back in the pack so we should be safe.

We can be pretty confident that cold will arrive at the weekend, but there are two key questions:

1) How much snow will fall, when and where? Like I said earlier, it battleground/frontal situations a few hundred miles change in position can leave you high and dry or low and wet with a relative small snowy boundary in between (but if we get it right, we could have over a foot of snow).

2) How long will the cold last for? Whilst all the 12z model op runs that I've seen have shown Icelandic high and therefore long lasting cold and plenty more snow chance, there was the ECM 0z this morning which showed mild returning, and the GEFS 12z (i.e. the ensembles) would seem to support this, so sustained cold isn't 'locked in' yet.

Will be VERY interesting on Thursday when the potential snow events at the weekend will start to come into range of the NAE/NMM high res models and when if the models continue to be good the Meto start to issue any warnings / BBC forecasts start to discuss potential snow in detail.

Edited January 8, 2013 by mikeocarroll

[Bobby]

ECM precip chart for Monday:

Upper air:

The result is lots of snow for us in Wales. Of course it'll change but plenty of potential.

[whiskers]

omg soooooooooooo excited,so want to tell everyone,will bite my tongue till about thurs/fri

[soupsurfer7]

I must say it all looks very interesting tonight... but there WILL BE DOWNGRADES. However, given the charts showing, we can probably afford SOME downgrades. Always the possibility the models are still getting all this wrong though, so cautious optimism. I wouldn't go around telling everyone it's going to snow yet or you may end up with egg on your face.

Let's hope for a good dumping here in Wales though

[keithlucky]

omg soooooooooooo excited,so want to tell everyone,will bite my tongue till about thurs/fri

Wise words whiskers wait until ecm Thursday night then we can EXPLODE!!

[foggybrynna]

Hia guys im new to this do you guys use the same charts as HTV Wales weather ad they say we havin rain for weekend id like to know as my wife is due to have a baby anyway thanks

[keithlucky]

Hia guys im new to this do you guys use the same charts as HTV Wales weather ad they say we havin rain for weekend id like to know as my wife is due to have a baby anyway thanks

Good luck my first child was born in the snow in 1991 hour and a half walk lol.They always behind with a change in weather they catch up soon. Edited January 8, 2013 by keithlucky

[foggybrynna]

Got little further than that to walk bout 8 miles to hospital but thanks for that

[Icequeen]

Just a ikkle bit excited........for anything other than dankness......but the ECM........ekk

[keithlucky]

Just a ikkle bit excited........for anything other than dankness......but the ECM........ekk

Nothing wrong with that come weekend ?

[Snowmadsam]

Hi guys,

Just wondering as I have exams what chances of snow are down west?

Please let me know as I have exams next week

Sam

[foggybrynna]

whats the chances of having snow in Wales on weekend as we only have fog where live lol

[Bobby]

Hi guys,

Just wondering as I have exams what chances of snow are down west?

Please let me know as I have exams next week

Sam

Really can't tell yet with any certainty - too far out - but significant snow on the weekend and into Monday is a possibility so worth keeping an eye on how things progress.

[J10]

Hi guys,

Just wondering as I have exams what chances of snow are down west?

Please let me know as I have exams next week

Sam

As I said on the other thread, it is a long way out, and a lot can happen by then. How many times has snow been forecast at T+120/T+144 and then not materialised. On the balance of probabilities, no, but there are possibilities.

Firstly as the low pressure pushes east, and we are on the northern side of the low, (one advantage of the Jet Stream being so far south), with very cold Easterly winds digging in. This could give frontal snow to some.

Then there is a chance of some snow from the North West later on the weekend.

Up until this point, synoptically is reasonably likely. Beyond this anything can happen, but if we get the deep cold forecast, then snow can come from any direction. as Feb 09 showed.

The charts really are great, and I hope they come off, but I am just a bit cautious, for now at least.

One final word of caution the ECM 00Hz today was not that great, if tomorrows charts are as consistently as good as the 12Hz runs, then expectations can rise.

Hia guys im new to this do you guys use the same charts as HTV Wales weather ad they say we havin rain for weekend id like to know as my wife is due to have a baby anyway thanks

Better to watch BBC weather, with good old Derek and even Points West, with Ian Fergusson who regularly posts on this forum. (fergieweather)

[Icequeen]

Nothing wrong with that come weekend ?

I think I can manage lol...........

silently excited ......thinking about camping out at the Swansea snow shield HQ it ensure no mildies get to turn it on

[freeze for all]

whats the chances of having snow in Wales on weekend as we only have fog where live lol

You can't have lived in Brynna long then because I live in Llanharan which is right next to Brynna and we don't do to bad when it comes to snow! We had about 8 inches in 2009 12 inches 2010 and from what I can remember as kid we had our fair share then to. Here is a pic from 2010 the yellow buckets are about 14-15 inches high! But then again it is foggy at the mo so u are right lol

Edited January 8, 2013 by freeze for all

[Bobby]

You can't have lived in Brynna long then because I live in Llanharan which is right next to Brynna and we don't do to bad when it comes to snow! We had about 8 inches in 2009 12 inches 2010 and from what I can remember as kid we had our fair share then to. Here is a pic from 2010 the yellow buckets are about 14-15 inches high! But then again it is foggy at the mo so u are right lol

That December 2010 snowfall was great, came as a surprise and we had almost a foot lying by the end (including 3 or so inches from a previous fall) and it didn't melt at all until well after Christmas I remember. Second best snow event I remember here after 1996 I think it was, where we had about a foot in one go.

Edited January 8, 2013 by Bobby

[soupsurfer7]

With Saturday's uppers looking marginal, perhaps if the rain is heavy enough we could get some evaporative cooling going on?

[Bobby]

With Saturday's uppers looking marginal, perhaps if the rain is heavy enough we could get some evaporative cooling going on?

GFS 18z looks better than the 12z for Wales on Saturday, things slightly further south, if it's rain initially it'll probably to turn to snow eventually

No point looking at the fine details at this stage, 50 miles N or S could mean the difference between rain and tons of snow. The precip certainly looks heavy so yes you'd expect some evaporative cooling to help things.

Drawing air from the continent into things too and you don't need such low uppers with a drier continental flow.

Edited January 8, 2013 by Bobby

[Bobby]

Monday's event still on too, not as good as the ECM. But shift the first band 100 miles South and the second band 50 miles West and many in Wales could be buried by the end of Monday! Best case scenario of course.

[foggybrynna]

Sori guys but BBC Wales weather said the same as HTV rain for sat

[Wales123098]

What the hell is BBC weather on about? Everything is looking like severe cold and snow and they don't even mention it. It's only a few days away! People need some sort of warning.

[foggybrynna]

Sori only sayin what BBC said

[J10]

http://news.bbc.co.uk/weather/hi/news/newsid_7760000/7760862.stm

This forecast explains it quite well. (For Saturday) - A much better forecast than the one on BBC Wales earlier.

The 18Hz run is better than the 12Hz run for the event on Monday, it comes at a better time of day, early morning as opposed to midnight (Sunday), with colder dewpoints, 850HPA air temp and thicknesses.

Medium Range into FI on 18Hz is stunning as well.

Quite simply would deal on the GFS 18Hz run if offered and the ECM 12Hz (wouldn't mind the 12Hz GFS either). If the outcome is anything like these charts most people would be happy.