Snow - Friday November 25th 2005

Danno

Hope the mods don't mind a new thread on this, it looks very likely now that alot of Ireland could be affected by snowfall this Friday.

A set of cold fronts are expected to dive southwards over Ireland late Thursday/Friday introducing a much more colder airmass and an unstable one too.

A trough of showers are expected to move in behind these cold fronts, where the possibility of snowfall is greatest.

As always, a N airflow is finicky and some areas will miss out, but there is a good chance of a polar low developing and pushing down over Ireland, a situation that happened last December 25th. There is a reasonable chance that this could happen as -40c air temps aloft over still mild seas to our north encourage such developments.

I would be less hopeful though for significant snowfall along the south coast, due to mountains of Kerry, Tipp and Wexford.

Some very low daytime maximum temperatures are guaranteed with probably Valentia maxing out at 6c, I expect Clones, Mullingar and probably Casement to have maxes of 0c.

Winds will be severe as a tight pressure gradient gets established, offshore winds could be up to 80kmph and gusts much higher.

On another note, if the second cold front passes over in the small hours of Friday morning, it could fall as snow over highland and possibly at lower levels well inland, Castlecomer pleatau and the Thurles hills areas springs to mind...

Discuss!

lucernarian

I live in a somewhat weird position where I have sea almost to the north of me (Dundalk Bay), as well as to the east. If the wind should take a north-easterly slant, would that bring more snow to the east coast or should we all hope for north-west winds?

IIRC the 1996 event (January I think??) started off with a front moving southeastwards and I got a lot of snow out of that. Some places could do very well indeed out of this. I wouldn't want to be in the Sperrin Mts. on Thursday night:D. Seriously though, the aspect I have most confidence in is the precipitation levels as low pressure like that will greatly aid shower formation.

The issue is temperature I feel, which is why I expect a covering, nothing more, of snow, thanks to my smallish height advantage. The small majority of the country can mainly expect sleet IMO.

Edit: On that note, I checked the 12z ensemble generated today and the Dublin 850 hPa temps for Thursdaymidnight have fallen to -7 with near universal agreement.

I suspect you are better placed than most to see snow To_be_confirmed
You are just at the point where troughs may be at their widest as the slip into the Irish sea assuming a southeasterly track as per the 12z

And if the BBC countryfile forecast is to be believed


(ps that screengrab is from chalkie who seemingly is from Dublin and may be on here so I hope he doesnt mind)

As regards this thread,it could have waited a day or so, but you cant contain yourself Danno,I see that from other places...

lucernarian

Earthman, I hope that the big white mass in the picture moves south;)

Did anyone see the farming forecast today? I missed it as I was out for lunch.

My final thought tonight is that this will be a hit and miss affair and to get anything more than a dusting you may have to rely on luck. Snow showers could be sharp indeed, but I see little in the way of any organised bands crossing the country on the day. A polar low could do something, and would be great for me, but I'm not an expert in that kind of thing.

I'm going to play the waiting game.
Nite all.
Matthew.

P.S where's Weathercheck? I expected him to be ramping here. "The Day after Tomorrow" etc.:D

Danno

Fax Charts out - still looking good!

http://217.160.75.104/wz/pics/brack3.gif

http://217.160.75.104/wz/pics/brack4.gif

looking good for who though?

It's in the bag I'd say for the North(and possibly you Gonzo)
But predicted temps above 4c in the southern half of the country is not good for snow-and that includes you Danno.

That said, the data out tonight is slightly colder.

Danno

Predicted temps - I would not be too worried yet about them, also, I usually find here is up to 1c cooler than Kilkenny and up to 0.5c cooler than Birr.

You'd need lower still though.
Just trying to be realistic here.
The devils in the detail and that wont be known untill about 48 hours out.

Theres no indication as yet as to where any widespread precipitation is going to come from to penetrate that far down the spine of Ireland.
It's route would have to be all across land which as we know kills showers.
Theres certainly nothing on those fax charts to signify any enhanced activity travelling down through Ireland except for the two cold fronts, one fairly benign and the other a little more active-but with rain(the cold air being behind it)
Theres plenty to indicate that the direction of any precipitation has to be directly north south.
So a shower entering the North has a 300 or 400 mile land track to make it down to south leinster-it can only do that with a trough and they seem to be wanting in those charts to head towards wales and not down the spine of Ireland.

A polar low would be good for you though , we shall wait and see I suppose.

Danno

I disagree Earthman, for starters it is under 200 miles to go, and with upper air windspeeds of over 100mph, it wouldn't have a lot of time to die out, the winds will be stronger than last Christmas, and remember John Eagleton's trough earlier this evening???

I'm just commenting on what you posted up.
Theres no evidence in them.

You say they are looking good yet they say nothing much for the southern half of this country.
Note I'm not saying nothing is going to happen obviously.
I'm commenting on the charts you posted.

You are well more than 200 miles in a straight line to the north coast by the way, Wales is probably closer
I'd say 300 would be about it, and closer to 400 for parts of the south coast.

Danno

Correction 174 miles from here in Durrow, South Laois to Malin Head - Autoroute is great!

Arklow is 185 miles from Malin Head!

The trough in the fax charts has to pass over all of Ireland - maybe with the exception of the west Dingle peninsula...

The time the fax charts show is when the trough has cleared through and the 528 line ahead of it!

Looks very good IMO!

Keyzer

I love snow...

I dunno about that

According to this Derry is 253 miles from Durrow.
Factor out the bend in the road and you more or less get mallin head.

Doing a road map for weather is useless of course because weather doesnt travel by road and secondly, it takes no account of the topography it has to travel across.

Thats a second cold front in those fax charts by the way and not a trough.
The third item is a trough and those fax charts actually support that heading into the UK after its done with the North.
If you study that chart its heading them south east...

Theres no certainty as to where troughs will be, or where they will travel on friday.But they will be there so keep your fingers crossed and you may get one.
Those charts dont have the detail that you need to support troughs coming down over Ireland(I suspect being UKMO output-we are ignored...)
You may as well keep them crossed for low temperatures too but if as I suspect the showers from this air are heavy they'll bring their own cold air with them so they're likely to be very very wintry wherever they fall especially in an inland location like yours.

billy the squid

http://www2.wetter3.de/Animation_06_UTC/108_30.gif
is still predicting snow for late on thursday night.

my guess is that there will be snow on thursday night/friday and will have turned back to rain by friday night/saturday morning.

also some serious polar lows showing up in FI according to 00Z run.

This mornings 755am forecast on morning Ireland from met Éireann went for rain and hail showers on friday with less showers on saturday and a spell of rain on sunday...

Danno

I wouldn't mind anything MET IE say up till 925z forecast Thursday night...

Gonzo

yeah ive a feeling the best most of us will see is sleet with rain further south and west, the snow will prolly be restricted to high ground. If this was a few weeks later things would work out better. Late last night the BBC went for 6C on Thursday and Friday, thats not even cold enough for sleet with snow confined to northern areas of Scotland, but this forecast seems to change every few hours so we wont really have any real idea till the day itself.

Danno

Hey, Earthman, what was Ireland's coldest last night???

Gonzo

certainly the frost last night was very bad, our car was covered in ice and still is, the garden is still white in sheltered areas.

Gonzo

Gonzo wrote:

yeah ive a feeling the best most of us will see is sleet with rain further south and west, the snow will prolly be restricted to high ground. If this was a few weeks later things would work out better. Late last night the BBC went for 6C on Thursday and Friday, thats not even cold enough for sleet with snow confined to northern areas of Scotland, but this forecast seems to change every few hours so we wont really have any real idea till the day itself.

I'm inclined to agree.
There will be wintry showers though and snow is possible, its just that its too early.

Last night here was breezy at times with some cloud cover.
We did have a ground frost, but nothing special.
It's already up to 10 c here

There are too many people willing through dreaming to get carried away in the hype that other posters on other weather boards put on charts a week or more out from an event.

The people that do this never learn and then seem all disappointed when the snow they've been blowing about turns out to be sleety rain.

Supercell

Jaysus but the frost was hard here this morning..had to spend about 30 mins hacking it off the car, been a while since so much effort was needed!! (higher dew temps today so expecting much more in the way of fog and slippery roads tomorrow morning )

As to Friday, I reckon there is a reasonable chance of many of seeing some very wet snow falling and in some places (about 5+ miles inland) locally might see some settle, the mountains though should get a nice covering, if the wind dies down on Saturday plan to go up there taking snaps galore!!

Ray777

http://news.bbc.co.uk/1/hi/uk/4457744.stm

:cool:

DMC

Heh. I came here to post the same link too.
Must be getting cold if I'm posting here once more.

Supercell

Danno wrote:

Rather quiet here today - gosh you'd know Weathercheck was away

I see your doing yer best to ramp in his absense on TWO , nice to see this forum hasn't descended into the usual "Day After Tomorrow" scenarios for once but good discussion of the models.

Supercell

Its interesting that the models are push the cold low further westward, so much so that if http://217.160.75.104/wz/pics/MT8_Dublin_ens.png is accurate..then precip late on Thursday is going to be snow- if its freezing before the precip arrives then settling is going to be widespread..but thats unlikely.

If this was late December or Jan/Feb or even March would say its game on for lying snow wherever it falls.

Last time I saw the gfs move a polar low westwards towards Eastern Ireland, it ended up mid atlantic, the snow likelyhood given the time of year is really on a knife edge..I fear even by wednesday night we wont be able to forecast it with anything more than 30% accuracy.

It's not going near us according to the Eagle but might get a little closer and increase the instability even more in the Irish sea.
High ground is where most of the actions going to be.
A slight northeasterly would be good for a dumping in the wicklow mountains and places like roundwood.
Too early really - we need the near continent to freeze and the far continent & scandi to absolutely freeze to the bolleeks and then theres business if the easterlys are prevalent this year.

Supercell

Earthman wrote:

Too early really - we need the near continent to freeze and the far continent & scandi to absolutely freeze to the bolleeks and then theres business if the easterlys are prevalent this year.

Yep agree totally, still snow falling in November is a pretty rare thing here and as long as it doesnt stick and my car starts , am all for a little cold snap!!

Danno

It's a "wait and see" game now - but I am quite confident! Todays model run putting the low pressure closer to E England in the North Sea is a good thing - but only good for Ireland and Wales.

billy the squid

possible fly in the ointment?

A STRONG AND LARGE NON-TROPICAL LOW PRESSURE SYSTEM OVER THE CENTRAL
ATLANTIC CENTERED ABOUT 900 MILES WEST-SOUTHWEST OF THE AZORES
ISLANDS IS MOVING LITTLE. THIS SYSTEM IS GRADUALLY ACQUIRING
TROPICAL CHARACTERISTICS AND COULD BECOME A TROPICAL STORM AT ANY
TIME. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH
SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

its moving east, yesterday the outlook said 950 miles southeast of the azores.

http://www.nhc.noaa.gov/tafb/danger_atl_15.gif
http://152.80.49.216/archdat/tc05/ATL/95L.INVEST/qscat/fnmoc/20051122.1254.FNMOC.wind.95L.INVEST.40kts-988mb.312N.40W.jpg

the atlantic needs to stay quiet for the next few days

Takeshi_Kovacs

Danno wrote:

Correction 174 miles from here in Durrow, South Laois to Malin Head - Autoroute is great!

Arklow is 185 miles from Malin Head!

The trough in the fax charts has to pass over all of Ireland - maybe with the exception of the west Dingle peninsula...

The time the fax charts show is when the trough has cleared through and the 528 line ahead of it!

Looks very good IMO!

damn ... and i was hoping to go up a white Mt. Brandon

Danno

Mountains of Kerry should get a load of snow.

Danno

http://www.metcheck.com/V40/UK/FREE/warnings.asp <<< risk map.
I thought more of Ireland would be higher risk, like a political map to me.

maquiladora

Danno wrote:

http://www.metcheck.com/V40/UK/FREE/warnings.asp <<< risk map.
I thought more of Ireland would be higher risk, like a political map to me.

Notice how the high risk area falls exactly within the boundries of Ulster? It looks provincial based, so theres no grey area. In reality there would be a good degree of overlap between those zones.

Danno

DID anyone see Ger Flemming at 2350z tonight, OMG - A widespread snow shower event - countrywide max of 4c, thats including coastal temps and inland temps and then getting an average.

Snow likely in variable amounts for everyone!

Permission to (continue to) Ramp!

This is looking VERY good!

LFCFan

Metcheck has changed slightly in that they aren't giving as much snow and not as long now. Still as cold though!

full forward

batten down the hatches!!!

Severe Weather Warning for Snow
Frequent snow showers are likely to give accumulations of between 3 and 8 cm below 250 metres during the period 1200 hours Thursday to 2400 hours Friday in counties Donegal, Mayo, Sligo, Leitrim and parts of Cavan. Strong to gale force Northerly winds will occur during the same period, giving blizzard conditions at times and causing some drifting.

Mothman

"parts of Cavan"

They're getting specific. Does this mean that the other parts of Cavan will see more or less, or the northern, or western part......

I think I will get to see flakes but nothing lying, though Roundwood is only 15 mins away

These showers will be fast moving and so probably won't leave much precipitation during a passing.

Hmmmm

They are getting concerned now.If the precipitation comes down like the october 2003 thunderstorm northerly then Dublin could get a lot of showers.

I'm not expecting a whole lot here unless the showers going down the Irish sea are extremely fat and clip the coast.
I'd be confident enough that Dublin will get quite a few heavy showers
A slight northeaster is unlikely so the lack of that twist militates against this location.
Also We here are totally sheltered by the Wicklow mts to the North

maquiladora

UKMET have their own breakdown of where they think it will disrupt us most....

EARLY WARNING of Heavy Snow and Blizzards Issued by the Met Office at 10:29 on Wednesday, 23 November.
The Met Office is forecasting that very strong northerly winds will extend across the UK from Thursday to Saturday, with all areas at risk of seeing some snow. Current timings suggest that the onset of the wintry weather will be around 0600 Thursday in northern Scotland, 1800 Thursday for Northern Ireland across to northern England, and overnight Thursday/Friday for southern parts.

full forward

From UK met...

Severe Gales, Blizzards & Heavy Snow
Affecting Co Antrim, Co Derry & Co Down
Heavy snow showers and gale force northerly winds will give blizzard conditions at times through this afternoon and into tonight. The wind will gust to 70mph in association with heavy snow showers at low levels in coastal areas exposed to the northerly gales, and more generally over ground above 600m. The public are advised to take extra care.

LFCFan

I can safely say that Dublin will NOT see any signifigant snowfall and this doesn't come from any scientific data or advanced knowledge of weather systems etc etc. It comes from the fact that Dublin sucks when it comes to getting snow and I don't see tomorrow being any different

Yeah,I'd be surprised if similar weather didnt affect Louth and meath to an extent later and down along the East coast to Dublin too in the next 24 to 36 hours.

It's hard to put detail on it in a northerly but activity in the Irish sea looks like being vigourous enough to hit the coastline in this northerly and that would mean sleety rain , wet snow for the sea level areas and definitely snow for the higher ground.
Settling snow is pretty much guaranteed on the high ground if the showers come inland to Dublin and wicklow and maybe on the lower ground if the showers are heavy.

Its a case of watch the radar as the situation is borderline.
Up north though,I'd be confident of sticking snow at lower levels depending on shower penetration and heaviness and I'd include all of Ulster in that and north leinster to an extent too.
Some areas escaping though such is the localised nature of showers.

fatherdougalmag

LFCFan
Mod: RipOffIreland

Just another rip-off, eh LFCFan?

I suppose if there's any shower activity preceeding this potential snow event, it will most likely result in the snow melting as soon as it hits. That is, unless, a freeze/frost sets in as it gets dark.

Gonzo

yeah its unlikely we'll see anything around Dublin and if it does snow it will melt as soon as the sun comes out (like it did last year). Also this window of opportunity for snow over most of the UK & Ireland is barely 24-30 hours which lasts up till friday night, after that it will be still very cold but too mild for any snow, more like rain/sleet.

I think the North-west and most of Northern Ireland will do quite well tonight and tomorrow tho - maybe 2 inchs at lower levels. Don't be dissapointed its still too early in the season for any proper snow to last any length of time.

Gonzo,I dont see why your home area shouldnt see some settling snow(not much mind 1cm , if you get more its because you've been lucky with the showers and unlucky if its less or none-but the main point is, its possible) It all depends on the showers and where they go.
I wouldnt rule it out.
The probability is higher though across Louth I think.

Incidently the real cold air hasnt arrived yet-thats tonight tbh so no need for excitement yet.

Taf from Dublin airport

EIDW 241200Z 241322 29018KT 9999 SCT018 BKN025 TEMPO 1322 30023G37KT -SHRA SCT018CB PROB30 TEMPO 1922 5000 -SHRASN SCT006 BKN016CB=

They are expecting light rain/snow showers there later this evening-30% probability
and snow by morning with similar probability.
Conservative but wise.

bennyc

Leitrim : A sleet shower a few minutes ago small bit of snow and judging by how cold it got since this am could be in for a lot more this evening

We've just had one here too
Mostly hail pellets with snow flakes mixed in
It took an inland track and moved very very quickly from lugna quilla in a straight line south to here

Temp down to 4.4c now dp -0.4

Gonzo

the rain shower we had turned to snow as it cleared - had a few flakes out of it but its clear again now and so bitterly cold

Dutchboy

I clicked a link by accident on an old thread, sent me to weathercheck's site, it seems he is getting very excited indeed!

I know he's banned , but is he over-exaggerating or is there a chance this may happen? Havent seen the likes of it in a long time :rolleyes:

"Latest indications just recieved now forecast a serious weather development for the eastern counties of Ireland It is forecast just recieved a few minutes ago that a vicious little polar low may form around 3am in the north Irish sea and push southwards giving winds gusting to 75mph on the east coast coupled with driving heavy snow. Low level area's from Down to Wexford wil recieve upto 5 inches of snow through the morning with drifting and snow pasting itself to poles and any northerly facing surfaces. The rush hour will be extremely treacherous and we advise to listen to your Radio or news Bulletin in the morning before setting of. Dublin is likely to see its worst at around 4-9am tomorrow with 5 inches of snow lying in places.

5 inches? :eek: :rolleyes:

bennyc

just saw the coolest thing a full blue blue sky still bright and a black cloud comming from the north and covering the entire sky place turned black in 5 minutes. we are on a hill here so you could see the lot pity I have no camera with me. Apparently speaking to collegues in North Donegal its snowing up there the last while