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

Itssoeasy

I'm guessing Cork won't see any snow or ice then ? It was cold last night but it's okay today.

Slashermcguirk

Snowbiee21 wrote: »

It’s easy said but hard done , things change all the time you must understand it’s not a case of giving a warning and then the warning pulling off . Either way I think met eirrean are doing a great job giving out the warning even just as a caution because as other posters said , it will be a nowcast situation .

I am not saying it is easy and I think to the main extent met eireann offer a very good service. However it is times like this that you really need them to deliver and this is their job, they are professionals. 12-24 hours out shouldn’t be overly challenging. I totally get though that predicting things 3 or more days out is far more challenging with so many variables. I would imagine they have more systems and weather models at their disposal so within this closet time frame they should be accurate

MJohnston

There are a lot of people complaining about forecasters still not knowing how this is going to go, so maybe it's worth simplifying the situation slightly for noobs (and I'm not an expert so someone correct me if I get something wrong here):

The snow will be produced in the interaction of a large band of precipitation approaching Ireland from the south-west and a weather front that will slide down from north to south. The snow line seems to be determined by the placement of that front in relation to the precipitation.

The uncertainty comes from multiple directions - how far south will the front move, and how quickly? How far north-east will the precipitation band move, and how quickly? Where will these two things meet, and when? So we're talking about the placement of weather systems that are thousands of km in size, over an island a few hundred km in size. And yet the forecasters can still predict it'll be somewhere on the island!

The problem is that a shift of say 100km is absolutely miniscule and insignificant to the scale of those weather systems and therefore the models find it difficult to pinpoint that kind of thing with 100% certainty, but 100km is a massive distance for those of us in Ireland.

Edit: and yes, you can add to the model uncertainty the usual uncertainties that kod87 mentions below like very localised variations in climate and slight variations in wind direction. There are a huge number of variables in this kind of event.

kod87

snowstorm445 wrote: »

Seems like the AROME model has the deepest snow across the South Midlands, Galway down to Carlow/Kilkenny. Parts of high ground in Munster look like they might do well, even Wexford looks like it might get a bit.

Amazing how the models haven’t nailed this down yet. Expect further changes for the 12z

I don't think any model will nail it down accurately, that's just the nature of borderline events like this one. micro climates, elevation, wind direction are all local variations that will determine whether it's snow or rain or a mix for any specific location

snowstorm445

Itssoeasy wrote: »

I'm guessing Cork won't see any snow or ice then ? It was cold last night but it's okay today.

Some snow on high ground in the north of the county a possibility I’d say. Highly unlikely in the city unfortunately.

pistolpetes11

The tools of the trade that MET Eirean use can't lock down whats going to happen so I wouldn't be expecting Met Eirean themselves to be able to say with certainty whats going to happen ,

The thrill of the chase :D:D:D

snowstorm445

kod87 wrote: »

I don't think any model will nail it down accurately, that's just the nature of borderline events like this one. micro climates, elevation, wind direction are all local variations that will determine whether it's snow or rain or a mix for any specific location

You’re certainly right about local outcomes, the precipitation type etc. But even the location of this front has changed rapidly over just a few days. Originally 3 days ago it looked like the snow would miss Ireland entirely (or only clip the far north), and then it looked like it would cross most of the country (a late Sunday night/Monday morning affair). Now it’s predicted to hit tomorrow morning, and even between current runs and those this morning the front is further south and is predicted to clear much more rapidly. Must be phenomenally difficult to forecast anything given these rapid changes!

PukkaStukka

mhiggy09 wrote: »

Anyone tell me the outlook for Cavan?

Hungrier than a famine :pac: :pac:

MJohnston

Weather forecasting is like Wedding Planning - you book the photographer, the cake, the DJ, the dresses, the suits, arrange the guests in a seating plan, and make a schedule for the meals and speeches. Then on the day the bride is 1 minute late, or Uncle Andy has one too many wines before his speech, or someone swaps their seat with someone else, and suddenly the whole thing is fúcked. Plus afterwards you will always have a bunch of people moaning that it wasn't the way they would have done it.

Arbitrary

MJohnston wrote: »

Weather forecasting is like Wedding Planning - you book the photographer, the cake, the DJ, the dresses, the suits, arrange the guests in a seating plan, and make a schedule for the meals and speeches. Then on the day the bride is 1 minute late, or Uncle Andy has one too many wines before his speech, or someone swaps their seat with someone else, and suddenly the whole thing is fúcked. Plus afterwards you will always have a bunch of people moaning that it wasn't the way they would have done it.

That makes sense. So tell me, will it snow in Dublin?

Larbre34

Arbitrary wrote: »

That makes sense. So tell me, will it snow in Dublin?

Unlikely near sea level or inside the M50, roughly. Higher ground and inland suburbs may see a decent amount for a time and you may get ninja falls any place if all factors hit the sweet spot.

Pangea

A real winters day here in Donegal, some of the hail from Friday night hasn't melted all weekend. 2.2c

Mr Bumble

Give Franc a bell....he might know

ninebeanrows

Larbre34 wrote: »

Unlikely near sea level or inside the M50, roughly. Higher ground and inland suburbs may see a decent amount for a time and you may get ninja falls any place if all factors hit the sweet spot.

Looking at some recent output - I am beginning to question whether it will even precipitate in parts of Dublin!

bozharry1

What about Portlaoise.Do ye think we will get anything here:D

RobertKK

bozharry1 wrote: »

What about Portlaoise.Do ye think we will get anything here:D

Yes.

BBC showing snow for inland south east and south midlands tomorrow afternoon.

Danno

Very cold tomorrow night

ednwireland

1.2 Donegal sw about an hour ago had a rain shower which was rain at 100m asl

Kermit.de.frog

Struggling to see how eastern coastal counties see much more than a wet mix. Mostly it's likely to be rain.

However keep an eye on here as, even now, this could yet still bring snow to eastern parts.

This will be a 'nowcast' for those parts. Could yet see a surprise.

Still an event inland though. Still a lot of snow could fall in a short space of time in the midlands, west and northwest.

Comhrá

Limerick currently 3.2C, overcast & dewpoint 2C. @2pm

MJohnston

You can see how well the rain/snow boundary in the east aligns with where the sea winds start to lose influence:

Rock Lesnar

MJohnston wrote: »

You can see how well the rain/snow boundary in the east aligns with where the sea winds start to lose influence:

Ha im roughly on the line of rain and snow in that top chart, just like i said in an earlier post, i'll get a messy mix, while 5 miles over the road will be snowing like crazy

kod87

updated from met eireann, crucially for me it includes tipperary this time:) but it does not include dublin


STATUS ORANGE

Snow-ice Warning for Carlow, Kildare, Kilkenny, Laois, Longford, Wicklow, Offaly, Westmeath, Meath, Galway, Mayo, Roscommon and Tipperary
Significant falls of snow are expected Saturday night and into Sunday. Accumulations of 4 to 8 cm could occur quite widely with greater totals possible. Drifting snow locally at times too with brisk winds. Slippery paths and treacherous roads also due to snow accumulation and ice.

Issued:Saturday 09 December 2017 14:00
Valid:Saturday 09 December 2017 23:00 to Sunday 10 December 2017 23:00

Snowbiee21

MJohnston wrote: »

You can see how well the rain/snow boundary in the east aligns with where the sea winds start to lose influence:

Another **** further east and it could be game on . All to play for!

pad199207

Dublin out of the Warning now. Was going to stay in dublin tonight, definitely going to go down to Kildare instead.

q85dw7osi4lebg

Wicklow mountains tomorrow it is.

JCX BXC

I had a good laugh seeing West Clare with a very strong westerly wind, when around 50km north there'd be a strong easterly!

lolie

pad199207 wrote: »

Dublin out of the Warning now. Was going to stay in dublin tonight, definitely going to go down to Kildare instead.

Cavan gone off the warnings also. Hmmm

Danno

pad199207 wrote: »

Dublin out of the Warning now. Was going to stay in dublin tonight, definitely going to go down to Kildare instead.

South and west Laois is the place to be Pad!

Interesting that Kilkenny and Tipperary have been added to Met Eireanns warning

Reckless Abandonment

Bugger Dublins out.. Might take the missus to kildare village shopping then.