Forecasts for Cold Snaps/Spells and Snowy Weather only.

Snowbie

Today and tomorrow are very crucial in the model saga.Already there has been a split in some models of which way the high is going to go.WC posted a nice chart above and one in which we want.A close enough GL high wiil do fine if there is a chance of the white stuff.Some of the models (GME) has it parked on top of us.

We will get some sort of reality today and more tomorrow for sure on what to expect.

arctictree

OK - looks like Met Eireann have acknowledged this up and coming cold spell:

"The rain will eventually clear away east later on Friday night or early on Saturday allowing winds to veer northwest or north, and bringing a change to noticeably colder weather. "

Getting closer......

A

Cornilius

So what are the chances for us here in the east in seeing any of the white stuff?Will that Northeasterly make any difference for showers coming in off the irish sea on Tuesday?

ninebeanrows

The 12z is very interesting for Eastern Ireland and much of Ireland tbh.:D

From this coming Sunday through to at least the following Wednesday if the 12z were to occur there would be a number of periods of snow across the east and elsehwere across the country!

First possibility is sometime Sunday - http://www.wetterzentrale.de/pics/Rtavn1261.png

The Monday as the winds veer easterly - notice that little LP
http://www.wetterzentrale.de/pics/Rtavn1441.png

Then Tuesday general showers off the Irish sea
http://www.wetterzentrale.de/pics/Rtavn1681.png
http://www.wetterzentrale.de/pics/Rtavn1682.png - Very cold
http://www.wetterzentrale.de/pics/Rtavn16817.png - very low maxima

All in all a good innings this evening

Will be interesting to see how my new gfs forecasts interprate things later
http://weathercheck.net/wetter/hw3_986php_flatfile/hw3.php?forecast=intwx&alt=inttest&interval=3&placeid=eidw

Snowbie

I would use caution in predicting snow this far WC as the charts are subject to change.
It is more than likely that it will become colder but we could also have the HP sitting over us too dampning down the showers.The charts you posted would produce snow but you know how fickle they are.
Id say it is too early to start a general ramp about snow lets be certain that we know the source of the cold air mass and the direction to which we have to look.:)

Besides the charts look a whole lot better each day

Supercell

12Z is VERY encouraging imho, getting closer now, gowd it this turns into another letdown I'll go mental!

darkman2

The UK met office has issued an early warning for all areas including NI.


I am still reluctant to comment on this past 120hrs because there is uncertainty in how this may occur. The GFS looks good obviously but we need agreement from the other models. The ECM was good this morning but was an outlier in its ensembles so lets wait and see later this evening.

JamesM

Weathercheck wrote:

Somebody pinch me... is this January 2007 or have i been taken to some fantasy planet...

Or back to January 1947

arctictree

Still looking good for snow Mon/Tue and then cold HP conditions for the rest of the week. Might not happen or could be very alpine'ish. We'll know for certain at the end of this week and will also have an idea if there any fronts involved.

A

Gonzo

lookin at the charts now and it seems to been weakening slightly for monday/tuesday with the high pressure much closer to Ireland now:(?

Villain

Yep the 12z looks to be removing the slight chances we had of snow, but these charts will change alot before Monday.

The low pressure for thursday looks nasty.

arctictree

Gonzo wrote:

lookin at the charts now and it seems to been weakening slightly for monday/tuesday with the high pressure much closer to Ireland now:(?

Yes, but Sunday is looking interesting now though. If that low moves anymore to the east we could be in for a shock....In fact, may happen Sunday night.....

A

Snowbie

18z GFS has given up on the HP moving towards GL alright and wants to pay us a very close visit with a presure prediction of 1040mb.The chances of snow will have been downgraded alot for this country according to this run and as artictree said it might be just Sunday as our day of hope with the early days of next week will be clear cold and frosty.

As i said before it is probably the 18z on wedensday evening before we can paint a picture.Still time for an upgrade again or a downgrade.

Gonzo

unfortunately for us 9 times out of 10 its almost always a downgrade:(

MetLuver

I hear ya Man!!! We never seem to get a break in this country.

rc28

morning everyone,
has anyone been looking at the radar this morning? there is a well organised band of precipitation moving over the west now, i hope some of it is half wintry. met eireann sem to have upgraded the amount of showers because on the radio it said "prolonged" showers of sleet, i'm so desperate to see cold weather i'll take sleet anyday!

ch750536

Had some sleet here this morning, but we are elevated.

Snowbie

Please use this thread for forecasts and models only.

Post [thread=2055023550]here[/thread] for wintry stuff.
Cheers.

MetLuver

Had some very heavy sleet here in Navan , bout 9.35 turned to snow for a few minuits, Wind is very strong in showers too! WELCOME WINTER 07!!!!

Met luver Snowbie already told you to post that in the thread made for those reports that he linked to in his last post.
This thread is for forecasts only!

As for next week-850's arent low enough imho and sea temps are too high so theres probably going to be too much modification of any cold sourced air feed.
Theres a big difference you know between cold 850's heading this way via a Scandi/Europe North sea area that has been historically warm than say if they were coming down to us via an already frozen Europe.
The only positive is its happening in january which is ideal but also all this is too far on the wrong side of reliable at the moment.
We know theres cold air coming but we dont know what track it will take and the exact positioning of all the factors that determine that track.

A slack cold flow is no use given the historically high sea temps,it will be modified too much such that showers wouldnt be as heavy and they would be more sleety in nature near the coast and on low ground.
Worse than that it will be sapping its cold into areas of Europe and Britain that will be drawing on its cooling powers before it gets here and then still it has to pass over a warmer than usual Irish sea and Atlantic (in the case of a northerly)

So I'm not enthused by whats coming at all (yet)

All eyes to the models in the next few days and see what they firm up on.

arctictree

Is that a LP over Munster on Monday on wetterzentrale?

Monday still looking very interesting.

A

darkman2

Snow looks very likely later Sunday and Monday depending on where you get precipitation. Dew points will be low enough and the 528 DAM thickness line is well south of Ireland. The 850s will be around -6, -7 and that well low enough for snow. Thats as far as I can go atm because there is far too much uncertainty after this. There is plenty of time for unpgrades or downgrades. The ECM is not too bad at all for example.

darkman2

darkman2 wrote:

The 850s will be around -6, -7 and that well low enough for snow.

Well we had rain last february with 850's of -8 on the East coast so thats not a certainty.
You are dealing here with a lot of uncertainty imho - air at height will be well cold but there will be a lot of surface warming on it making snow a touch and go subject.
Lets be realistic about this.

arctictree

Tristrame wrote:

Well we had rain last february with 850's of -8 on the East coast so thats not a certainty.
You are dealing here with a lot of uncertainty imho - air at height will be well cold but there will be a lot of surface warming on it making snow a touch and go subject.
Lets be realistic about this.

Yes but we have snow falling today on a predominantly westerly flow. Charts for next week are definitley colder.

Also, Jan 21st is statistically around the coldest time of the year. (1 month after the solstice). (is this correct??)

I would say, all in all if there is precipitation, chances are it will be of the wintry kind.

A

darkman2

Tristrame wrote:

Well we had rain last february with 850's of -8 on the East coast so thats not a certainty.
You are dealing here with a lot of uncertainty imho - air at height will be well cold but there will be a lot of surface warming on it making snow a touch and go subject.
Lets be realistic about this.

I am being realistic. I never said it would snow from the East coast. Im talking about the northerly and given we are not windward any precip that comes inland will fall as snow IMO. Look at today for example. Sunday and Monday imparticular will be colder. We have the trough coming south on Sunday night too. So opportunities there. BTW I have been very cautious with the upcoming spell. Nothing is certain yet. From the charts im expecting wintry showers of sleet and snow on Sunday and Monday. Mostly in the west and north.

http://cirrus.netweather.tv/fax/PPVN89.png

Snowbie

artictree wrote:

Yes but we have snow falling today on a predominantly westerly flow. Charts for next week are definitley colder.

Mainly over the higher ground in the west.I would imagine sleet on the lower ground and by the coast with the higher DPs.

Also, Jan 21st is statistically around the coldest time of the year. (1 month after the solstice). (is this correct??)

Thats the first i heard of that tbh.January of late has been one of the milder winter months.March 06 last year was colder than Jan 06.

darkman2

The 12z GFS is out and its excellent. Check out the ice days on Tuesday and Wednesday:D

The snow too;)

http://www2.wetter3.de/Animation_12_UTC/138_30.gif

Nice upgrade there. Still a long way to go but the 850s get down to -11 on this run:eek:

ninebeanrows

Very good 12z tonight prolongs the cold spell and it gets very cold.

Not much precip about though but we will see closer to the time.

As for the whether it will be cold enough debate.

The air from Monday of next week as progged on tonights 12z run would be cold enough for snow ie. 850's of -8c - -10c amd dewpoints below freezing.

During Sunday it may well be 50:50 however with higher ground recieving snow but the snowline will lower to sea-level as we move into Monday morning.

It is all about dewpoints for me... i have found there crucial in the last few years.. If the dewpoint is below freezing your half way there IMO and 850's of anything lower than -6c with a freezing or below dewpoint is good enough.
850hpa temps of -6c with a dewpoint of +1c / +2c is a different story however

Good post WC.
Yes it's all about the dp's too given the awkwardness of the recent lower athmosphere warm up.

Longfield is practically guaranteed snow in his location imho from the start.

I've noticed that it seems par for the course that model output is better for snow on one run,less better on the next and great on the next etc etc-so the happy pills come if the better runs are still showing within 96 hrs or so.

Having said that this is nice though unreliable being 8 days away-However it is still a possible indication of things to come.

http://85.214.49.20/wz/pics/Rtavn1802.png