Wales Cymru Cold Spell Regional Discussion

[keithlucky]

As pretty as the metociel snow charts are, to me they are unreliable, nothing wrong with posting them they add to the fun, but always need to bear in mind that they tend to overdo snow amounts.

As for midweek showery potential. Looking at the detail.

850HPA temps are around -5c to -6c, dam levels are around 520-528 and thicknesses around 1295-1300m.

These values just about pass the basic criteria for snow, so there is a chance, however very much a marginal event, the colder air is further east and some may well see their first snowflakes of the winter, however by no means is this a snow sticking event apart from mountains.

Of course this is based on current runs, and the event may turn out to be different to the current forecast.

I think we see snow in the heavier showers the damn levels around 528 is a pretty good guide that"s why i like the fax charts because the most experienced forecasters added with model output seemed to be the most consistent in trying to predict the weather forecast.

[TonyH]

On the other hand, next week is shaping up to be much less marginal, although by then high pressure may prevent the snow (for a while anyway!):

[TonyH]

Incredibly the last lying snow here was in January 2011, and that being on just one morning and hardly anything!

[keithlucky]

Incredibly the last lying snow here was in January 2011, and that being on just one morning and hardly anything!

Normal winter then T late 90 s early 2000 just as bad most years many a year one snowfall was a blessing 2 was global cooling. Edited December 3, 2012 by keithlucky

[TonyH]

Remember them well Keith, also the late 1980's several Winters of very little snow until Dec 90 when the Midlands got a foot!

Edited December 3, 2012 by TonyH

[keithlucky]

Remember them well Keith, also the late 1980's several Winters of very little snow until Dec 90 when the Midlands got a foot!

So having these chart output is great the youngsters are be spoilt very close last year to being very cold year before, amazing,europe mainland have had 4 amazingly cold yrs is the gulf stream slowing down as many having predicted ,something is happening. Edited December 3, 2012 by keithlucky

[Daniel Miller]

Andy, I can't wait to hear your reaction when you see the ECM Ensembles!

What do you reckon Keith?

[mikeocarroll]

I expect that some of the current showers affecting Wales are wintry over higher ground - radar shows falling as sleet over Brecons and I would expect the tops to be white tomorrow. Even down here in the valley at 200m I'm half expecting to see a bit of sleet any minute, dewpoint is hovering around 0c (temp hovering around 2.5c) and uppers are -3c so enough for me to have a quick look outside in the hope of seeing sleetiness in heavy showers; but more in hope than expectation.

[J10]

3 times last winter, we had snow which stuck for a few hours but didn't make it over night, once due to a snow to rain event, 2 other times, showers of snow settled during daytime thawed from underneath due to the mild ground during the evening.

However to me this doesn't count as a Snow lying day.

Astonishing really that 2009-10 had 28 days of snow lying. 2010-11 had 13 days of snow lying with 2011-12 had 0.

[keithlucky]

Bloody amazing i was laughed at when i said 2110 HER WE go again plenty of opportunties again with Jackone streamers appearing in charts cannot wait for fax charts tonight.Can we beat 28 days lying snow this year let take bets LOL.Yes -25bloody rediculous Daniel i be busy knocking doors we must ALL check on the old people, many cottages with retired pensioners were i live.

Edited December 3, 2012 by keithlucky

[Daniel Miller]

Bloody amazing i was laughed at when i said 2110 HER WE go again plenty of opportunties again with Jackone streamers appearing in charts cannot wait for fax charts tonight.

How do we repeat 2110 then? :L

[wizard.muh]

So having these chart output is great the youngsters are be spoilt very close last year to being very cold year before, amazing,europe mainland have had 4 amazingly cold yrs is the gulf stream slowing down as many having predicted ,something is happening.

Not sure about the Gulf Stream slowing down. Although it seems we are now in a period where, what was once highly improbable is now very plausible. Synoptically the situation is very interesting, I just really hope............

Edited December 3, 2012 by wizard.muh

[andymusic]

Andy, I can't wait to hear your reaction when you see the ECM Ensembles!

What do you reckon Keith?

I'M BACK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! - Well thanks for the tip off there Daniel (sorry for delayed posting - hospital all day again)

EASTERLY EASTERLY EASTERLY EASTERLY EASTERLY - here we go here we go here we go

enough of a reaction - just catching up - gonna look at gfs now - back in a minute

OMG OMG OMG OMG OMG OMG OMG OMG OMG OMG

Easterly - OMG - 2010 all over again - get the flippin supplies in - Easterly now showing for last few runs starting towards the end of high res now into FI - oh MY GOD - if these charts are right - just like Joe B has been a saying - crikey - it's looking flippin scarey - this could be very dangerous weather if this comes off!

STARTING A WEEK TOMOZ I WOULD Say - oh crikey! - the meto and pro forecasters must be having kittens - when are they gonna start warning us about this - i hope it's soon - everyone will need to be aware of the possible severity of this set up surely!

obviously we're not there yet - but wow!

absolute feet of snow

Edited December 3, 2012 by andymusic

[keithlucky]

How do we repeat 2110 then? :L

Blocking in place from USA across to Russia and hopefully see more attacks from the S West with more frontal snow than 2010 .

[andymusic]

So having these chart output is great the youngsters are be spoilt very close last year to being very cold year before, amazing,europe mainland have had 4 amazingly cold yrs is the gulf stream slowing down as many having predicted ,something is happening.

Nope Kieth - sun is currently very lazy - therefore we have cooler/colder temps - I keep saying this is simple logic - less warmth from our heating system - more cold - isn't it obvious - but then you say - ah but it's more complicated than that - but it's not - next 3 decades will suffer these kind of winters - we have been warned - last few years they have all been wittering on about this! - welcome to our mini ice age - we were told/warned by some pro forecasters who know a thing or two about how our earth gets it's heating or cooling - and it's as simple as that.

SUN GOES TO SLEEP OR PRODUCES LESS HEAT/OUTPUT - EARTH COOLS - What's so difficult to understand?

Edited December 3, 2012 by andymusic

[Daniel Miller]

I'M BACK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! - Well thanks for the tip off there Daniel (sorry for delayed posting - hospital all day again)

EASTERLY EASTERLY EASTERLY EASTERLY EASTERLY - here we go here we go here we go

enough of a reaction - just catching up - gonna look at gfs now - back in a minute

OMG OMG OMG OMG OMG OMG OMG OMG OMG OMG

Easterly - OMG - 2010 all over again - get the flippin supplies in - Easterly now showing for last few runs starting towards the end of high res now into FI - oh MY GOD - if these charts are right - just like Joe B has been a saying - crikey - it's looking flippin scarey - this could be very dangerous weather if this comes off!

AHAHAHA! Knew you'd have some balanced and sobered post to make to put a dampers on things >.<

Hope all is well, or getting there!

GFS 18z massive downgrade on the 12z BUT, I generally tend to focus on 00z and 12z runs and disregard the other 2 GFS runs, especially when they divert from the trend such as this.

As Keith says, await the FAX charts and the ECM 32 update from SnowKing at around 11pm! Until then, we party!

Blocking in place from USA across to Russia and hopefully see more attacks from the S West with more frontal snow than 2010 .

I was referring more to your use of the date 2110 >.< But yes, that could be a possibility, one that we are all praying for no doubt.

Edited December 3, 2012 by Daniel Miller

[welshwizard]

I'M BACK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! - Well thanks for the tip off there Daniel (sorry for delayed posting - hospital all day again)

EASTERLY EASTERLY EASTERLY EASTERLY EASTERLY - here we go here we go here we go

enough of a reaction - just catching up - gonna look at gfs now - back in a minute

OMG OMG OMG OMG OMG OMG OMG OMG OMG OMG

Easterly - OMG - 2010 all over again - get the flippin supplies in - Easterly now showing for last few runs starting towards the end of high res now into FI - oh MY GOD - if these charts are right - just like Joe B has been a saying - crikey - it's looking flippin scarey - this could be very dangerous weather if this comes off!

STARTING A WEEK TOMOZ I WOULD Say - oh crikey! - the meto and pro forecasters must be having kittens - when are they gonna start warning us about this - i hope it's soon - everyone will need to be aware of the possible severity of this set up surely!

obviously we're not there yet - but wow!

absolute feet of snow

long way off yet Andy but things do seem to be heading in the direction of cold and possibly snow. I also noticed yest and today that the council been putting new salt bins in areas around here that I have never seen before and also filling the old ones. maybe I not noticed before but they certainly filling them all,in fact over the top to be honest.

[Marcus_surfer]

Just give me a night of heavy frequent jackone snow streamers. I'll be happy then.

[andymusic]

Just give me a night of heavy frequent jackone snow streamers. I'll be happy then.

Think it might just end up worse than that Marcus!

[SnowStorm(Jamie)]

Ok well the 18z model output for the GFS and NAE is now out so lets take a look at the snow prospects for Wales over the next few days.

If we start with tomorrow we have a few things a cold NW Flow with upper air temps of around -3C down to -5C filtering through in a few spots show on the NAE here:

We have sub 528 dam air over Wales more or less all day apart for later in the evening where it tends to wrap itself around the area of low pressure so slight mixing out of colder air during this point before the low pressure drops south allowing a more northerly flow once more re-introducing the colder air and sub 528dam:

< NAE @ Midday tomorrow showing sub 528dam

< Slight rising of sub 528 dam air as warmer air gets pulled in more or less from the west over Irish sea.

< NAE Showing colder air being re-introduced by Wednesday morning

As that low drops south Tuesday night into Wednesday morning some precipitation will move southward along an occluded front as shown by the Met Office fax chat:

http://images.meteoc...fax36s_htl6.gif

Dew Points generally around 3C down to 0C across Wales (Higher to the west coast colder to east Wales). So showers tomorrow which should get going quite fast and get pushed inland on a fairly strong NW flow will be of rain and hail on immediate western coasts turning more wintry in nature inland especially over high ground. Showers that get pushed into central Wales may well contain some snow more so in the heavier showers.

With regards to the front pushing down from the North i think some snow is certainly possible on the back edge as the colder air catches up with the front. Something to perhaps consider here is you usually find the colder air undercutting evaporates the precipitation as it heads south & also factor in as the front goes over the higher ground of mid Wales.

A spell of sleet and snow is possible i would say again in central and eastern Wales where the precipitation is shown to be heavier on the NAE and the dew points generally lower. A wintry mix in low ground southern Wales on the back edge of the front.

So an interesting few days at least with regards to weather prospect's

Looking further ahead here is the ECM 0z Ensemble mean i saved on 30th Nov (Friday) for 7th december:

Now here is the ECM Operational run today at 96 Hours (for same time):

Trough over Western Europe and UK, Ridge over Mid Atlantic the ECM Mean also picked up on the general NE Flow which is now showing on the ECM operational model for 7th December. Giving the fact i have watched this over the last few days i would place high confidence in this outcome with a general NE Flow by the end of the week as the low pressure clears eastwards. Indeed Colder rather than milder then that ridge to the west perhaps having some more influence on our weather as it builds closer towards the UK.

[SMU]

Jamie your better off using the 850-1000 thickness charts on the NAE for sub 1290 DAM

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2012/12/03/basis18/ukuk/th85/12120506_0318.gif

for example- not the 500's

best regards

Steve

[marclt]

I expect that some of the current showers affecting Wales are wintry over higher ground

The best we're having way out west is hail. We've had quite a few coverings this evening. But it's melting in a strong breeze. Gusty during those showers.

[andymusic]

Jamie your better off using the 850-1000 thickness charts on the NAE for sub 1290 DAM

http://expert-images...120506_0318.gif

for example- not the 500's

best regards

Steve

welcome Steve to the welsh part of the forum - you must be very excited at the potential now showing up in the charts!

[marclt]

3 times last winter, we had snow which stuck for a few hours but didn't make it over night, once due to a snow to rain event, 2 other times, showers of snow settled during daytime thawed from underneath due to the mild ground during the evening.

We had over a week last winter. But more like 3 weeks the year before, in between various shorter snow and black ice events!

[andymusic]

Bloody amazing i was laughed at when i said 2110 HER WE go again plenty of opportunties again with Jackone streamers appearing in charts cannot wait for fax charts tonight.Can we beat 28 days lying snow this year let take bets LOL.Yes -25bloody rediculous Daniel i be busy knocking doors we must ALL check on the old people, many cottages with retired pensioners were i live.

I'll have a bet that we can beat 2010 decembers longevity this time - I'll have a £5 on that Keith!