Snow/Ice Warning for Ulster : PM 17th/AM 18th, Jan 2018

Kermit.de.frog

The main models continue to weaken storm potential for Wednesday evening and in to Thursday and increase snow potential as the storm system looks to move further south.

With the reduction in the wind threat comes an increase in the snow risk.

The storm thread is here

https://www.boards.ie/vbulletin/showthread.php?t=2057829980

At the moment all of Ulster and possibly northern counties of Leinster are in line for persistent and sometimes heavy snowfall.

This may yet change further. The ECM, for example, has snow potential even further south taking in more of Leinster and northern Connaught.

Given we are within the 48 hour timeframe big changes shouldn't be expected but still some uncertainty there.

For now the focus is Ulster - including Cavan, Monaghan and Donegal.

This could be disruptive for the province.

I'd go with 5 - 10 cm - locally more and on high ground. Looks a decent enough event.

Wine Goddess

Kermit I love your enthusiasm for snow! And your knowledge....

piplip87

Great in Virginia Cavan and often the weather we get is what is forecast for North Leinster. Hopefully get a nice pasting from this

M.T. Cranium

Not downgrading the wind potential for south and central counties but this snow threat is real if the track ends up inland, it simply won't warm up much north of the track of the low and could stay mostly snow in Ulster and high ground in Connacht before, during and after passage of this low.

If it intensifies and follows this track, very tight gradients would develop, and even more snow potential would exist (5-10 cm sounds about right to me also).

mirrorwall14

M.T. Cranium wrote: »

Not downgrading the wind potential for south and central counties but this snow threat is real if the track ends up inland, it simply won't warm up much north of the track of the low and could stay mostly snow in Ulster and high ground in Connacht before, during and after passage of this low.

If it intensifies and follows this track, very tight gradients would develop, and even more snow potential would exist (5-10 cm sounds about right to me also).

Any chance it will run south and plaster the midlands as well as the north?

Donegal Storm

Arome going for high ground in Ulster only



WRF and Arpege a bit more optimistic though again mainly higher ground

Kermit.de.frog

Hirlam - slightly further south with the track.



Guess it will be somewhere in between.

sdanseo

Bodes well potentially for a few more of us. HIRLAM fairly nailed today's events. Logic would suggest based of its precip frame above that any more than 50km further south on the morning runs and we could be talking disruption in a lot of Leinster come Thursday morning.

I'm a bit confused though, uppers from HIRLAM for the same frame would suggest far too warm?

pad199207

Those in Ulster and Leinster should be keeping a very close eye on this.

pauldry

Sligos right on the border for this.

Interesting ...again...this great Winter

nacho libre

sdanseo wrote: »

Bodes well potentially for a few more of us. HIRLAM fairly nailed today's events. Logic would suggest based of its precip frame above that any more than 50km further south on the morning runs and we could be talking disruption in a lot of Leinster come Thursday morning.

I'm a bit confused though, uppers from HIRLAM for the same frame would suggest far too warm?

not necessarily. you can get snow with such uppers when you have cold air in place, provided the wet bulb temperature is low enough(0.6) you sometimes can even get snow at 4c. indeed some of the greatest frontal snow events in Ireland have come about in marginal situations. i would like to think given the winter we have had, we will get one epic countrywide frontal snow event- it has to happen at some stage

Donegal Storm

Arome is generally very good for snow predictions from what I've seen in the brief time I've used it, it forecast the frontal snow events last month almost perfectly. For some reason though it didn't pick up todays event at all, it showed very few showers over the country all day (not even rain showers) and no snow accumulation at all. Must be an issue with whatever global model its getting its input conditions from for the Atlantic though still bizarre it was so far off

This is what its showing tomorrow, snow anywhere above approx 150-200m to start with and I assume the orange cross hatching is sleet



Before eventually transitioning to snow for most areas in north Ulster

sdanseo

Orange = hail or graupel "niege roulee" literally round snow
White = snow or sleet "niege verglacante" - literally icy rain

nacho libre

So North Mayo, parts of Sligo, Cavan could get a blizzard tomorrow night

I bet though it will end up further north if it intensifies quickly while engaging the jet stream and fionn's energy.

Kermit.de.frog

This thread probably needs an orange warning in my opinion. This could be a very disruptive event.

Can a mod please add the following counties to the OP?

The counties are Antrim, Armagh, Cavan, Louth, Sligo, Leitrim, Meath (North), Tyrone, Donegal, Derry, Fermanagh, Down, Monaghan, Roscommon.

Blizzard like conditions are highly likely at times.

Also high ground in Wicklow will be appalling - avoid.

Duration is 6 - 9 hours from night fall tonight.

M.T. Cranium

00z guidance so far not much change, if anything it has nudged north a few miles on the GFS and Arpege, about the same on GEM. Track still close to border of NI and ROI.

Periods of snow rather than a blizzard perhaps, for inland Ulster. We should get a pretty big signal when it passes the M6 buoy around 17-18z.

justy182

Thanks Kermit for your work this week. Got a good dump yesterday. Slight thawing this am but nice to see. Just wondering about this event. My job like many here is extremely weather and safety related and coincides unfortunately with the onset of this event. Has there been increaesed confidence in this over night ? Many thanks again.

Kermit.de.frog

justy182 wrote: »

Thanks Kermit for your work this week. Got a good dump yesterday. Slight thawing this am but nice to see. Just wondering about this event. My job like many here is extremely weather and safety related and coincides unfortunately with the onset of this event. Has there been increaesed confidence in this over night ? Many thanks again.

No problem. Yes there is increased confidence.

It's not uniform across the board though. It may be the case southeast coasts of the north may see mixed conditions. Generally near coasts snow is likely to be diluted. Get any way inland though (Newry in your case) and the risk of snow increases dramatically.

My advice would be keep up to date and be prepared. No need for concern, however. It's short lived and over night.

Disruption likely to be Thursday morning rush hour after snow has passed.

Hope that helps. It's difficult to be exact at the best of times in a mesoscale sense (and the variables with your location).

I'd say you would be right to be prepared for snow.

justy182

That's great K. Thanks for that.

RazorT

...

glossy

Yep another good call KdF . I remember years ago you nailed the timing of the big snow that was going to hit D15 .

MJohnston

Met Eireann's model, which didn't perform all that well yesterday, but still:

https://twitter.com/MetEireann/status/953535170489081856

Gaoth Laidir

Looking good for the northern half of the country alright.

Why are there two threads on the same storm? This snow is directly related to Georgina so shouldn't it be in the same thread?

cherryghost

Another few pushes south on the charts today please

Malayalam

Gaoth Laidir wrote: »

Looking good for the northern half of the country alright.

Why are there two threads on the same storm? This snow is directly related to Georgina so shouldn't it be in the same thread?

Would be handy alright.
Anyways, we got the Greenland Express, several inches of it, can't get the car down the hill. We got a good deal of wind last night also. Thawing now with sleety rain. Looks like we are maybe gonna get this Georgina too with her coat tails full of snow - blizzards maybe,it seems , so feck that, my dental appointment looks like it is down the Swannee.... (Sorry, normally I am a snow fan)

pauldry

the province of Ulster and North leinster will see snow

Snowbiee21

pauldry wrote: »

the province of Ulster and North leinster will see snow

Where exactly is north Leinster

sryanbruen

Snowbiee21 wrote: »

Where exactly is north Leinster

Em.... Longford, Louth, Meath and Westmeath

piplip87

Snowbiee21 wrote: »

Where exactly is north Leinster

Louth, North Meath, North Longford

Lumi

Mod Note

Off topic attempts to derail the thread have been deleted
If you want to debate whether north Leinster is in Ireland or not, take it to PM...

sjb25

coming into the weather forum during these events calm down people

pad199207

Orange warning out for snow and ice

STATUS ORANGE

Snow-ice Warning for Cavan, Monaghan and Donegal
An Atlantic depression will cross Ireland this evening and early tonight bringing a spell of snow on its northern flank. This will be followed by scattered snow showers later in the night and Thursday. At present, the main risk of appreciable accumulations is limited to Ulster.

Issued:Wednesday 17 January 2018 10:00
Valid:Wednesday 17 January 2018 18:00 to Thursday 18 January 2018 12:00

Oscar Bravo

Aldergrove (Belfast) forecasting heavy snow from 7pm onwards,clearing after midnight. Some parts of the north are going to get pasted!

Gonzo

Oscar Bravo wrote: »

Aldergrove (Belfast) forecasting heavy snow from 7pm onwards,clearing after midnight. Some parts of the north are going to get pasted!

I feel this is going to end up being a golden winter for much of Northern Ireland. The eastern half of Northern Ireland is doing particularly well and they could well end up with a serious dumping of snow tonight. The Mourne mountains must have some very deep snow there already. These areas also had an insane snow event during March 2013, with scenes that rivaled the 1982 blizzard.

Hooter23

It's so annoying how much snow Northern Ireland gets compared to Galway considering its not that far away:mad:

munsterlegend

Hooter23 wrote: »

It's so annoying how much snow Northern Ireland gets compared to Galway considering its not that far away:mad:

I am sure they say the same up north about Scotland!

tylercollins

Gonzo wrote: »

Oscar Bravo wrote: »

Aldergrove (Belfast) forecasting heavy snow from 7pm onwards,clearing after midnight.  Some parts of the north are going to get pasted!

I feel this is going to end up being a golden winter for much of Northern Ireland. The eastern half of Northern Ireland is doing particularly well and they could well end up with a serious dumping of snow tonight. The Mourne mountains must have some very deep snow there already. These areas also had an insane snow event during March 2013, with scenes that rivaled the 1982 blizzard.

I remember that night very well, took the chances and headed for the Glens of Antrim and my god what a snow fest it was!  I remember driving up a mountain road, heading back towards home with maybe only 40 miles to go and came across a tree that had blocked the road, turned round, tried another road, this time the snow was the main problem, it just kept getting deeper and deeper until eventually the snow started bottoming out the jeep and making the wheels float.  In the end we had to do a 3 hour detour to get back home.
https://scontent.flhr4-2.fna.fbcdn.net/v/t1.0-9/48039_1406792349583619_1587502817_n.jpg?oh=b3b785cf401723c034ff273d2bf57cea&oe=5ADC3A32
https://scontent.flhr4-2.fna.fbcdn.net/v/t1.0-9/1896883_1406792382916949_1704463915_n.jpg?oh=ccfe576b1b7a78e56549d4b52cd1231d&oe=5AE4E47F
https://scontent.flhr4-2.fna.fbcdn.net/v/t1.0-9/1966669_1406792346250286_807331778_n.jpg?oh=b1a902ac7d82b9075ae054e369b46b91&oe=5AEFD680

FrancieBrady

What is the timing for this event please? When will it start?

Rebelbrowser

For us down south, as suggested in MT's forecast this morning, we aren't without hope of more snow tomorrow afternoon / evening. The always understated GFS offers the following right now.....



A bit of support (but not much) from Hirlam and Euro 04.

Will keep an eye out just in case.

Gaoth Laidir

Met Éireann's aviation chart for 1800Z this evening shows double warm fronts crossing the country eastwards at 40 knots (the first one stretching from Sligo to Wexford). Widespread moderate rain/drizzle, with occasional moderate snow north of 54N.

They have the low centre 988 hPa located at 54N 14W, or about 200 km WSW of Belmullet.

4068ac1elhodqr

Think this Orange warning (for snow/ice) was a bit too late.
The MetUK had issued this already for much of Ulster/Border regions effective from 3pm Tues to midnight Tue, now over.
Hence many roads closed last night, and schools closed early yesterday and still this morning.

Today (Wed) onwards will mainly all be about rain accompanied by very strong winds,
the Snowarmageddon is probably over except for elevated/exposed positions in Donegal for a short time.

loughside

Gaoth Laidir wrote: »

Met Éireann's aviation chart for 1800Z this evening shows double warm fronts crossing the country eastwards at 40 knots (the first one stretching from Sligo to Wexford). Widespread moderate rain/drizzle, with occasional moderate snow north of 54N.

They have the low centre 988 hPa located at 54N 14W, or about 200 km WSW of Belmullet.

I`m roughly 54.2N, and 240feet asl

Rain? Snow?

Both?!!

Donegal Storm

tylercollins wrote: »

I remember that night very well, took the chances and headed for the Glens of Antrim and my god what a snow fest it was!  I remember driving up a mountain road, heading back towards home with maybe only 40 miles to go and came across a tree that had blocked the road, turned round, tried another road, this time the snow was the main problem, it just kept getting deeper and deeper until eventually the snow started bottoming out the jeep and making the wheels float.  In the end we had to do a 3 hour detour to get back home.
https://scontent.flhr4-2.fna.fbcdn.net/v/t1.0-9/48039_1406792349583619_1587502817_n.jpg?oh=b3b785cf401723c034ff273d2bf57cea&oe=5ADC3A32
https://scontent.flhr4-2.fna.fbcdn.net/v/t1.0-9/1896883_1406792382916949_1704463915_n.jpg?oh=ccfe576b1b7a78e56549d4b52cd1231d&oe=5AE4E47F
https://scontent.flhr4-2.fna.fbcdn.net/v/t1.0-9/1966669_1406792346250286_807331778_n.jpg?oh=b1a902ac7d82b9075ae054e369b46b91&oe=5AEFD680

Did you go up Glenshane at all? The Pondarosa was totally encased in snow the next morning, the whole front of the building was just white with huge drifts. Couldn't risk pulling over for a picture as the hard shoulder was under deep snow but disappointing one never appeared online.

I think that was actually the last time I've seen any meaningful lying snow at low levels before last night, even at sea level in Belfast the snow was about a foot deep and didn't melt until well into April

munsterlegend

Rebelbrowser wrote: »

[qu AAJuote="Accumulator;105869339"]Think this Orange warning (for snow/ice) was a bit too late.
The MetUK had issued this already for much of Ulster/Border regions effective from 3pm Tues to midnight Tue, now over.
Hence many roads closed last night, and schools closed early yesterday and still this morning.

Today (Wed) onwards will mainly all be about rain accompanied by very strong winds,
the Snowarmageddon is probably over except for elevated/exposed positions in Donegal for a short time.

[/quote]

I take it you agree rebel!

justy182

Its looking like this frontal event might be more of a far northern snowfall event. Would I be right? Im right on the border and looking at some of the graphics from BBc and Uk Met the snow seems to be further north. Thoughts?

typhoony

justy182 wrote: »

Its looking like this frontal event might be more of a far northern snowfall event. Would I be right? Im right on the border and looking at some of the graphics from BBc and Uk Met the snow seems to be further north. Thoughts?

I was thinking the same when I looked at this morning's GFS run, all depends how much mild air in entrenched in this system, but to my untrained eye maybe only higher mountains of Donegal will get snow. of course it does cool down again later tomorrow and Friday looks cold enough for snow if there is any precipitation around

piplip87

Looking like a wet one here for the night. Will be very surprise if I see any snow. Met Eireann may need to lift the Orange warning for Cavan as its still 4c here and lashing rain.

Danno

Temperatures dropping here in south Laois, they peaked at 6.4c earlier this afternoon, however they are 4.4c now. Light breezes around 10mph, gusting 20mph. All the snow has thawed. We had a little over 1cm covering here this morning. Not expecting any snow here tonight, currently raining.

Interesting to see how the Hirlam pans out. 12Z version has rain turning to snow in the north Meath & Louth area later in the evening. Currently raining here in Dundalk.

Oneiric 3

Danno wrote: »

Temperatures dropping here in south Laois, they peaked at 6.4c earlier this afternoon, however they are 4.4c now.

Same temp reading here: 4.4c. Wind backing SSW to SSE. 96% Rh.

Gonzo

temp here has after fallen from 5C, back to 4C.

From what I can see there is very little snow falling over Ulster. Lots of sleet there but it's turning back towards rain in some places for now.