Snow and Ice Warning : Saturday(PM)/Sunday 9th/10th December - SEE MOD NOTE POST #1

Kermit.de.frog

MOD NOTE

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**It would be helpful to all that when posting weather reports that locations are added in the post ( this can be kept general if preferred) **

Thanks



As requested.

Sunday will be an event for many Northern and North Western areas. With regards to other areas it's a delicate situation.

To summarise:

Rain will move in from the southwest on Saturday night but will meet embedded very cold air over the country. It will turn to snow as it moves northeastward. It's a classic "battle ground" scenario between different air masses.

It will fall as snow initially over North Leinster (it will turn back to rain for a time). Over Ulster and most of Connaught it will fall as heavy snow throughout the event. Large accumulations in these parts. I would be of the opinion at least an orange warning is needed for these parts as of now - possibly red nearer the time.

Later on Sunday as the system begins to unwind and move away it returns to snow over Leinster and turns to snow in Munster with accumulations here. Not as significant but could still be disruptive.

As it clears it gets very cold and icy - another hazard in itself. Temperatures will plunge Sunday night well below freezing. Coldest night of the year so far.

This looks a severe event in the north and northwest including northern Connaught right now.

There is still the risk of significant snow further south as well. This is not 100% nailed in terms of where this will effect. Regardless many are going to see a significant snowfall.

I think it is safe to say this will be the most significant frontal snow event the country has seen in many years for the areas effected.

This is 48 hours out. There is no doubt it will be impactful.

Another risk is flooding, a lot of water associated with this.

I would advise people in the north and northwest - and Connaught - to keep up to date on forecasts and be prepared.

nacho libre

I'll believe it when i see it. It has all gone pear shaped before with less than 48 hours ago for frontal snow on lower ground. It's likely some snow will fall over much of Ulster and high ground in Connacht. Mountainy man might be snowed in!

M.T. Cranium

I was thinking along these same lines, kermit, looking at the guidance this "morning" and my take will be somewhat similar although I could see how this slides southeast rather quickly and delivers more to the inland southeast perhaps?

Just looking at various guidance to see the spread, have not reached forecast stage yet but certainly as you say potentially a disruptive snow and ice event. Winds come around to northeast for some time Sunday night also, surface direction likely to be a bit too northerly for major streamer action but everything on a knife edge despite being 48-72h out.

KingdomRushed

A lot of movement still possible for this feature, latest updates from HIRLAM and ECM are taking the precipitation further south again meaning Midlands more at risk than the north if it does fall as snow. If the trend south continues precipitation could be light even in north Leinster.

dmcsweeney

Is this even likely to effect south west Munster?
Thanks,
Dave

Kermit.de.frog

Yes, the ECM takes it a little further south meaning snow more generally and less for the far north.

An event for most but for those on the east coast or in Dublin i'd be wary of that onshore breeze - a sleety mix or rain seems favored here. Later Sunday I think the snow line gets to the coast.

Kermit.de.frog

dmcsweeney wrote: »

Is this even likely to effect south west Munster?
Thanks,
Dave

Later Sunday, yes there could well be snow.

Snowbiee21

@kermit I would still say plemty of changes !

dmcsweeney

Kermit.de.frog wrote: »

Later Sunday, yes there could well be snow.

Thanks! I'm cutting a hole in the external kitchen wall for new doors so I can pretty much guarantee the worst snow since 2010

munsterlegend

Kermit.de.frog wrote: »

Later Sunday, yes there could well be snow.

I very much doubt it in Munster particularly the south west.

Kermit.de.frog

munsterlegend wrote: »

I very much doubt it in Munster particularly the south west.

Most favored when winds go Northeasterly.

kod87

dmcsweeney wrote: »

Is this even likely to effect south west Munster?
Thanks,
Dave

very very unlikely to affect any part of Munster especially the SW fringes

Donegal Storm

It'll almost certainly be rain in the southern half of the country, too early to tell whether the north will be affected. Current guidance showing snow over Ulster but I can't recall a single Atlantic battleground snow event in my lifetime so naturally I'm a bit skeptical

Kermit.de.frog

GFS ups stakes, further south, a lot more in play. Leinster, Connaught and south Ulster in the firing line. Munster later.

dmcsweeney

kod87 wrote: »

very very unlikely to affect any part of Munster especially the SW fringes

Sorry, south west may be a bit misleading. I'm between Macroom and Ballyvouney at about 200mASL. Still out of luck I guess though!
Thanks,
Dave

MJohnston

Could be quite a bit of good old rain and wind gusts on Sunday too:





Storm Dylan, anyone?

BLIZZARD7

Sunday looking more and more interesting, at the current rate the slider is tracking South I think the Midlands/Wicklow mountains will take the brunt of it. Wouldn't be surprised if the North largely missed out in the end- lots of uncertainty though and a shift north or south by 50 miles will make all the difference with this one.

Reckless Abandonment

GFS showing "potential" of 24 hours of snow for places .

Kermit.de.frog

MJohnston

HIRLAM latest run has Sunday just coming into view and it's going for a fair old pasting of snow for the mid-west, midlands, and a fairly large swathe of the east coast (although seemingly just rain/sleet in north Dublin):

BLIZZARD7

Kermit.de.frog wrote: »

4-8cm an hour possible if we go with a 10:1 ratio :cool:

munsterlegend

MJohnston wrote: »

HIRLAM latest run has Sunday just coming into view and it's going for a fair old pasting of snow for the mid-west, midlands, and a fairly large swathe of the east coast (although seemingly just rain/sleet in north Dublin):

I really can't see too much falling except on very high ground for most of Munster. There are too many things which can go wrong which usually do.

MJohnston

munsterlegend wrote: »

I really can't see too much falling except on very high ground for most of Munster. There are too many things which can go wrong which usually do.

Well the model run I posted shows only rain for Munster, so it's certainly not predicting snow for there.

Kermit.de.frog

MJohnston wrote: »

Well the model run I posted shows only rain for Munster, so it's certainly not predicting snow for there.

When the wrap around kicks in with the northeasterly rain will turn to snow in Munster;)

Snowbiee21

Looks as though the midlands and parts of the east could be in for a pasting

squarecircles

MJohnston wrote: »

HIRLAM latest run has Sunday just coming into view and it's going for a fair old pasting of snow for the mid-west, midlands, and a fairly large swathe of the east coast (although seemingly just rain/sleet in north Dublin):

Widespread snowfall there for Mayo,right out to the coastline, interesting times ahead.

woody1

so it probably wouldnt be an ideal weekend to be driving west to east today and east to west on sunday !

Kermit.de.frog

woody1 wrote: »

so it probably wouldnt be an ideal weekend to be driving west to east today and east to west on sunday !

I'd give it a miss.

A potentially serious situation is unfolding for more remote parts of the west.

Keep up to date.

KingdomRushed

This is quite exciting, however even at 48 hours these fronts can be inaccurately positioned by all models. There is every chance it will continue slipping southward in future runs bringing more and more counties out of firing line.

kod87

KingdomRushed wrote: »

This is quite exciting, however even at 48 hours these fronts can be inaccurately positioned by all models. There is every chance it will continue slipping southward in future runs bringing more and more counties out of firing line.

That's what I'm hoping, if that HIRLAM model is to be believed then a slight shift southwards and I'm in the business. Actually starting to think I might see a few flakes

KingdomRushed

KingdomRushed wrote: »

This is quite exciting, however even at 48 hours these fronts can be inaccurately positioned by all models. There is every chance it will continue slipping southward in future runs bringing more and more counties out of firing line.

However it is unlikely to miss Ireland completely so I guess someone is gonna cop the white gold in significant quantity

Rebelbrowser

Kermit.de.frog wrote: »

When the wrap around kicks in with the northeasterly rain will turn to snow in Munster;)

Just to support Kermit's explanation, on current modelling the system eventuality slips away south east on Sunday night and at that stage Munster could get its turn (having had rain all day followed by a short dry spell as the system travels north east before it does its very welcome U-turn)....See below.

pad199207

Kildare, Laois and Carlow could be the sweet spots according to the current runs.

Still at 48hrs out lots of change to come

munsterlegend

MJohnston wrote: »

Well the model run I posted shows only rain for Munster, so it's certainly not predicting snow for there.

Oh right I thought the green was for snow?

munsterlegend

Rebelbrowser wrote: »

Just to support Kermit's explanation, on current modelling the system eventuality slips away south east on Sunday night and at that stage Munster could get its turn (having had rain all day followed by a short dry spell as the system travels north east before it does its very welcome U-turn)....See below.

If only. Perhaps a sleety mess at most unless you live on very high terrain.

arctictree

I'm getting a bit worried about this. I have a lot of sheep out on the hill and upland wicklow looks right on target for a dumping. Might bring them down into a more sheltered spot tomorrow. Don't fancy spending Sunday looking for sheep in snowdrifts!

MJohnston

munsterlegend wrote: »

Oh right I thought the green was for snow?

No - the colours show intensity of precipitation, the white cross-hatching lines on coloured areas indicate snow while the solid coloured areas indicate rain (or sleet).

Rebelbrowser

munsterlegend wrote: »

If only. Perhaps a sleety mess at most unless you live on very high terrain.

Sure we live in hope (though, as some say, its the hope that kills you!)

Cork Boy 53

Rebelbrowser wrote: »

Just to support Kermit's explanation, on current modelling the system eventuality slips away south east on Sunday night and at that stage Munster could get its turn (having had rain all day followed by a short dry spell as the system travels north east before it does its very welcome U-turn)....See below.

You`re the expert here so may I assume that, even if south Munster sees some snowfall on Sunday night/Monday morning, it is unlikely to cause significant disruption?

munsterlegend

Rebelbrowser wrote: »

Sure we live in hope (though, as some say, its the hope that kills you!)

I am trying reverse psychology at this stage. I thought I'd see some snow showers at least last night but nothing at all! Disillusioned!

Rebelbrowser

Cork Boy 53 wrote: »

You`re the expert here so may I assume that, even if south Munster sees some snowfall on Sunday night/Monday morning, it is unlikely to cause significant disruption?

Expert? - I know sweet f a actually! I just know where to find these charts. As for being able to actually read normal weather charts - way beyond me.

All that having been said, if that chart came off (a massive "if"), then actually you'd be looking at a decent dump of snow over south Munster. Day off on Monday stuff.

Buffalobill29

Rebelbrowser wrote: »

Expert? - I know sweet f a actually! I just know where to find these charts. As for being able to actually read normal weather charts - way beyond me.

All that having been said, if that chart came off (a massive "if"), then actually you'd be looking at a decent dump of snow over south Munster. Day off on Monday stuff.

How are the chances for snowfall looking for north-east Kildare?

Rebelbrowser

Buffalobill29 wrote: »

How are the chances for snowfall looking for north-east Kildare?

Again, on current guidance, good - though a few have mentioned proximity to east coast as being a factor in whether this falls as sleet or snow....

Snowbiee21

Buffalobill29 wrote: »

How are the chances for snowfall looking for north-east Kildare?

Pretty good

MJohnston

Buffalobill29 wrote: »

How are the chances for snowfall looking for north-east Kildare?

Take a look at some of the charts posted, they show this.

Reckless Abandonment

Buffalobill29 wrote: »

How are the chances for snowfall looking for north-east Kildare?

Kildare look good to me. Dublin is 50/50 as said before onshore winds will be mixing the temps a bit . Stroger the wind the more likely this will happen.

Macy0161

If the mixing does happen, any ideas on the snow line on the east of the mountains. Is it going to be more 230m asl heart break, looking up the fields seeing it at 250m?

SeaBreezes

The fricking excitement!! Maybe the cork snow shield will be broken??

BLIZZARD7

Macy0161 wrote: »

If the mixing does happen, any ideas on the snow line on the east of the mountains. Is it going to be more 230m asl heart break, looking up the fields seeing it at 250m?

This could of course happen but right now I reckon the snow line will be below you.

This won't be clear til tomorrow at the earliest.

Reckless Abandonment

Euro4 is real knife edge stuff .. I've a feeling nowcast will he the word of the weekend.
Sorry on mobile can't post.

Iancar29

Heres my forecast take on the current charts.


Ulster 1-5cms at low levels , 5-15cms above 200m and also inland areas, so Cavan and Monaghan areas

Connacht 5-10cms in inland areas. Roscommon, Leitrim areas.
10-20cms above 200m

Leinster 5-10cms in inland areas of Westmeath, Offaly, Meath. 10-20cms above 300m , so Wicklow mountains.

Munster After mostly rain at first ppn should transistion to sleet or snow in the evening. Accumulations are dependant on how quickly the temperature can drop during the showers but if it does then 1-5cms possible, 5-10cm above 300m.

As stated by other posters, this setup is on a knife edge , a nudge north or south of the front will make all the difference.