Colder this week, some wintry/snow showers, widespread frost and ice.

SleetAndSnow

Car fully thawed in the sun today in cork city, frozen again now already.

That is one major difference between this cold spell and other ones we get. It's winter, the sun doesn't last long, so the "max" temps are, in general, around for a lot less time then the min temps allowing more ice to form versus our usual cold spells in say March.

weatherfiend

https://www.boards.ie/discussion/comment/119968316#Comment_119968316

And if the squib is damp, you won’t get much of anything. In Dublin too Tayto 😉

.Donegal.

Precipitation for next 24 hours

newmember2

https://www.boards.ie/discussion/comment/119968362#Comment_119968362

So tomorrow day Dublin expected weather is to be similar to today?

.Donegal.

Potentially Eastern areas have a better chance tomorrow evening

19.44

Scattered showers tonight in Connacht and Ulster, some turning to sleet and snow later especially over high ground. Towards dawn, the wintry showers will extend further south.

Tomorrow

An icy start on Thursday with black ice and patches of freezing fog in places leading to hazardous travel conditions. There will be well scattered showers of sleet or snow in the morning, with little accumulations. Sunny spells will follow with wintry showers becoming confined to northern coastal counties during the afternoon, potentially also affecting some eastern areas tomorrow evening.

spookwoman

Was in Cork today and the moon was beautiful on the way home. Down to 1.7 at the moment in waterford city and a layer of ice is already on the car. Crystal clear so any Astronomy people out there it might be clear for the Occultation of Mars Thursday morning, starting about 4.55am. That's the Planet Mars disappearing behind the moon and reappearing about an hour later on the other side.

circadian

https://www.boards.ie/discussion/comment/119968604#Comment_119968604

We don't usually get cold frosty weather until January onwards, December is more often than not mild.

Gusser09

https://www.boards.ie/discussion/comment/119968343#Comment_119968343

Id be of that opinion too. Its bitter cold out now in north kildare but nothing different that other winters.

I found the 16 or 17 degrees in the middle of november a hell of more surprising than this.

If it were -4 or -5 id understand the drama.

https://www.irishexaminer.com/news/arid-41004839.html

Danzy

https://www.boards.ie/discussion/comment/119968840#Comment_119968840

November was much more bizarre weather wise, this is cold and early cold but it is not that abnormal.

nacho libre

https://www.boards.ie/discussion/comment/119968840#Comment_119968840

I think you'll find it will be different within the next few days in that we are not used to temperatures struggling to get above freezing during the day in December. Also while it's not excessively cold at present, it's not common for us to have fairly cold weather in December. The most likely month for snow and cold is usually February.

sryanbruen

The overall blocking pattern is more unusual than the temperatures. We haven't seen a -NAO like this in December since 2010, thus why a good few comparisons with that year despite it being misleading to the average Joe who doesn't give a toss to know what the North Atlantic Oscillation is or what relevance it means to us. Nonetheless, it is of interest to long-term weather observers like myself and others who are fascinated by this stuff.

The temperatures aren't that "overly" unusual meanwhile in comparison though certainly not an every winter case like some make out. If we didn't have such a modified atmosphere from all the warmth, I'd say this pattern would have been severe. However, low solar, long nights and slack flow will certainly help in plunging the air temperature values.

Rather than making assumptions without evidence, here's a statistical look at how unusual the temperature values are relative for the month of December.

A minimum temperature of at least -5C somewhere in Ireland happens on average every 2-3 years in the month of December. This has been achieved in 2020, 2017, 2016, 2014, 2012, 2010, 2009, 2008, 2007, 2005, 2003, 2002 and 2001 this century to date. With 62% of the years achieving it, it's clear this is rather common. However, the problem of using this quantifying method is that all it takes is one common frost hollow or notorious station for low minimum temps to achieve the value without considering regional variation where such a value will be much more common or rare for others. To counter this, I have made the below table from the same selection of stations used to calculate the Irish mean temperature (IMT) for the forecast contests minus Oak Park which has missing data from 1997-2003 and the likely return period based on available data for each temperature threshold at that station giving a reasonable estimate of how unusual it is.

Results on the whole are very similar across the four stations. Typically expect to see the following return periods for each threshold.

<-4C being every 2 years, <-5C being every 4 years, <-6C being every 6 years, <-7C being every 9 years and <-8C being every 13 years. Therefore, from this simple analysis we can say that -4C and even -5C to an extent are not that unusual to see in Ireland in December, at least at these stations. Coastal parts would be far more uncommon. Meanwhile -6C or lower can be once or twice a decade whilst -7C or lower can be anticipated once a decade and a half on average. This analysis doesn't take into account the count of days with threshold achieved in a December however - there were many nights for instance in December 2010 below -8C and even -10C wasn't all that uncommon in the frost hollows.

This analysis will probably blend away into the chit-chat but I wanted to see truly how "unusual" these temperature values are in the month of December in Ireland with statistical evidence rather than assumption.

Thank you for reading.

Cluedo Monopoly

Raining in west Galway

Villain

https://www.boards.ie/discussion/comment/119968882#Comment_119968882

Super info!!

nacho libre

A blocked pattern with widespread low temperatures is unusual for December. We do get low temperatures sometimes at night in December in a few areas, but it's not common for temperatures to struggle to get above freezing by day widely. Nor is widespread sustained cold by day or night common in December. So this pattern is unusual in that sense.

JanuarySnowstor

Apart from 09/10 I don't remember December cold pre Christmas in 50 years. Its that unusual!

Oscar Bravo

I was wondering how this got into my head...

https://youtu.be/k-HdGnzYdFQ

sryanbruen

https://www.boards.ie/discussion/comment/119968977#Comment_119968977

Well yes that is more unusual, the analysis didn't take into account what point of December the values occurred, it was for any part of the month. Another two significant years to add to your list - 1950 and 1981. Also 1878, 1879 and 1916 from a long time ago, I remember them well 😂

JCX BXC

Could we perhaps take all this chat about whether this event is usual or unusual, and whether the media and Met Éireann hype the events up as they do all other news items nowadays, to another thread?

Save this one from all the clutter and posters from the headache of reading it?

Larbre34

https://www.boards.ie/discussion/comment/119968604#Comment_119968604

Ice days, with or without freezing fog.

It is extremely unusual in Ireland for daytime temps to remain below freezing. The warning is for people moving about, who may encounter ice at any hour of the day on the roads and footpaths over the next few days, or those who are keeping livestock where the risk of feed and water pipework freezing is high.

If you think your smartarsery makes you sound either more knowledgeable that Met É, or somehow edgy, it really doesn't.

waterwelly

https://www.boards.ie/discussion/comment/119969036#Comment_119969036

It's only a few days since you were trying to be the smartarse telling us there was no need for an event thread, trying, and failing, to be more knowledgeable than everybody else.

Your words:

"There is no need for an event thread for this, its a few days of typical winter temperatures, in winter. Imagine!'

And don't forget your prediction for next weekend, again trying, and failing, to sound more knowledgeable than Met E.

Again, your words:

"Did you see the weather we had today in the east? Well, next weekend we will get a slightly colder version of that, so some evening hail and wet sleet with a snow line of about 250m."

JanuarySnowstor

Surprised there's not more talk about tomorrow afternoon for Dublin area?

Clearly an area of ppn clips the coast!

Coincides with a bubble of colder air!

Villain

https://www.boards.ie/discussion/comment/119969184#Comment_119969184

Wicklow hills and mountains could get a right covering! Harmonie has been increasing and decreasing potential on recent runs. Probably sleet near coast though.

Danno

Scandi is nice and cold, and only 11pm there with further hours of cooling to go.

Regarding the last few posts, this weather to this point is not unusual, however it is not common. As Sryanbruen alluded to above, cold overnight December lows around -4c and -5c are not infrequent, however a prolonged spell of nights with repeated values well below zero are not overly common especially this side of Christmas - moreso coupled with daytime highs struggling to get up around 3c.

Foggy Jew

Praying to the God of Pipes (Pan perhaps?) that all pipework in Chateau Foggy Jew can withstand this cold spell. Having experienced a burst pipe & ensuing flood 4 days before Christmas 2010, I never want to return to the misery of a flooded house. My blood runs cold when I see news reports of houses & businesses being flooded.

Take Care Out There, lads & lasses. Stay safe.

Neddyusa

https://www.boards.ie/discussion/comment/119969028#Comment_119969028

From past experience if you dont want chat and clutter - move to the Technical <120hrs thread - because there'll be lots of both on here.

Jim_Hodge

https://www.boards.ie/discussion/comment/119969184#Comment_119969184

Depends on where in Dublin. Tallaght direction looks set for some snow from 10pm tomorrow.

Gusser09

https://www.boards.ie/discussion/comment/119968944#Comment_119968944

But thats just incorrect. If we were staying below zero for extended period id understand the hype.

We are barely getting below zero at night at the moment.

Its a non event. Cold yes. But not as surprising as the 17 degrees on the 11th / 12th of november. Did we have a thread for that?

Villain

https://www.boards.ie/discussion/comment/119969342#Comment_119969342

If it’s a non event then why would you bother with the thread?

This is unusual weather for early December, sure hardy folk will wear their shorts and laugh it off and we have all seen colder but it’s an unusual weather event and this is a thread for it. I mean it’s not rocket science…

kittyn

I think you have made your point at this stage Gusser09 no?

mcburns07

..

Gusser09

Ok im out lads. Enjoy.

M.T. Cranium

The more severe cold of this current spell has not arrived yet, the leading edge of it has recently moved through Scotland and is starting to show up in Northern Ireland now. So I would hold fire until we see the temperatures especially overnight lows next 4-5 days. This is not going to rival Dec 2010 for cold or snow but it may be the coldest December spell since then.

At Portglenone (north end of Lough Neagh) I note that temps fell from 3 C to 1 C around two hours ago as this front passed, and temps in most of NI are now between 0 and 1 C. So there's a good potential here for sleet and snow to develop as this feature continues to move south overnight. Even small amounts of this can render driving hazardous, in fact small amounts may be the most dangerous since some motorists will expect normal traction and encounter black ice. The areas most at risk are probably the midlands and inland north to central Leinster. If it becomes clear ahead of this front in the inland south and then clouds over, that could also lead to black ice formation. Best chance of seeing the Mars-Moon event already mentioned by spookwoman earlier in thread would be inland south and southwest. As mentioned, timing of disappearance of Mars is around 0455h and reappearance around 0555h. Moon would be fairly high still at that hour in western portion of sky on its way to setting in northwest. This is an unusual occultation in that the moon is full and Mars is at opposition so it's a perfect alignment of four members of the solar system. (all occultations are by definition an alignment of three but not often the Sun as well). Hoping to see it here during the evening but rather cloudy at present (local time here being 3 p.m., because of the difference in perspective, we would see this at 03z to 04z or two hours earlier in universal time).

Oneiric 3

Forecast frontal chart for this coming Sunday. Looks like something out of the mid 1980s.

nacho libre

https://www.boards.ie/discussion/comment/119969342#Comment_119969342

I disagree. Three or fours days of temperatures struggling to get above zero or staying just below on some days is quite unusual for December. So it's understandable there is a thread about it. Also given the potential dangers of freezing fog and black ice it's right that Met Éireann have issued a warning about it to the public. Either way you slice it is an event worthy of discussion. The November mild was unusual but there was no dangers associated with it hence no real media coverage. Also milder weather does not generate the same interest as its rather obviously not a infrequent occurrence here, hence why there was no dedicated thread for the November mild, but I am sure it was commented on by a few posters here.

Meteorite58

The Hi Res models still picking up snow chance in the East Thurs evening. Converging winds along the coast, bit of CAPE , big lapse rates possibly leading to big heavy showers some moving inland or along the coast, possibly support by topographical lift from the Wicklow Mts, could have hail and wouldn't rule out the chance of lightning.

sdanseo

https://www.boards.ie/discussion/comment/119969543#Comment_119969543

Thundersnow!

Meteorite58

-2.3C here near Tralee about 2km from the coast.

spookwoman

0.9c here in Waterford, humidity seems to be on the rise.

US3

How often do we get ice days, where it stays below freezing for 24 hours? Last one I can remember is 2018 and obviously 2010, was there any others between in those 8 years ?

Meteorite58

An indication of wintry precipitation making its way inland in Northern counties, may be sleet or snow falling further inland.

Dazler97

-2.4c here in Carrick on Shannon, the showers are coming further inland but even a flurrie here will do

BrianG23

Just in case you forget, RTE is here to help

spookwoman

Still reading as 0.9c here in waterford with a heavy frost on the cars. Crystal clear for the mars occultation.

SouthWesterly

2.2C out there now in North Kerry.

je551e

-1 in south kerry

finnharpsboy

100% chance of snow between 6 and 7 according to the smart phone…. Unlikely

Condor24

A few spits of 'freezing' rain here in Offaly just starting. I can still see the moon and it's -2.1. Roads will be fun in a while. But unfortunately the 'warm' sector aloft is keeping snow away for us for now.

pad199207

Sleet here in Kildare with flakes falling

Champagne Sally

Light covering of snow here in Blessington

Brendan offaly

Light rain falling in Tullamore.

There was a frost and some freezing fog earlier.

Temp around 1c.