7th Annual Boards White Christmas Thread

Well, with less than 1,000 hours* to go to the big day, the tension is palpable. ish.

* (I didn't actually count btw, the relevant CFS chart is for +996 hrs...)

So how are things looking in terms of the big day and sneachta?

Not great I'm afraid. Here's the global position over western Europe as presently modelled which shows low pressure in chart with cold rain fed in on NW winds..



Looking at what that means for temps in our part of the world..



..not very promising I am afraid.

Alas 996 hrs is still, just about, FI in predicting terms so there is still a chance for things to change (and change and change and change) yet.

Until then, here's a seasonal cheer up image of Dublin's Grafton St .....

Well just over 600 hours to go (like you needed to be told).

We are still relying on the CFS for guidance at this remove - the GFS will be coming into range in about 12 days time.

The present CFS for the big day shows Ireland in between a mega area of High Pressure covering virtually all of continental Europe and low pressure systems on a path to our North:-



Temps on the big day are reasonably seasonal, see the 2m temp highs below:-



Still ages to go obviously so all can change. The most recent Christmas forecast on netweather, two days ago, is more upbeat saying "...again this week we've seen a trend for cold weather around the Christmas period. In fact this model, and a number of other signals are pointing towards cold air being with us for a good part of the second half of the December."

Anyway I will leave you with another seasonal taster. This time its Galway's Claddagh Quay..

Time for another update. Lots of doom and gloom about the return of Atlantic sourced weather on other threads but just as an opening observation, much of the country can and does virtually every winter get snow showers (often only fleeting admittedly) from north westerlies so even a mobile Atlantic pattern is not fatal for White Christmas hopes.

More to the point there is little evidence of a storm train setting up over the next 2 weeks and there is plenty of high pressure around to disrupt.

Looking more specifically at the weather models, we are still using the CFS for the big day but the gfs does now go out to 22 December and is worth looking at too.

In terms of the cfs, it currently shows as follows for the big day:-



High pressure over Europe in charge with weak low pressure to our north - far from the mobile westerly pattern being mooted elsewhere.

Temp wise this means uppers of:-


translating to



That's day time highs of 8c or so. In fact on the cfs, from 23 December onwards that makes Xmas day the warmest day left in 2016. Every other day over Xmas is colder, with typical samples below:-





So no signs of "mild muck" or anything like that on the CFS. Admittedly with that low pressure to our north ever present there will be a fair amount of showers and it will be pretty cloudy. In the context of cold though, that will never be far away.

The GFS as I said is out to 22 December now too and it again suggests the Atlantic will not be in charge by any means by Christmas week. Heres its chart for 20 December showing high pressure very much in charge:-



That translates into temps on the cool side as below:-



Thus it is thus all to play for and no way you can rule out a White Christmas - just yet anyway!

I will leave you with another seasonal pic, this time its Limerick in the snow...

12 days to go and still its all to play for in terms of Xmas day weather. Before discussing the chances of a white Christmas I think its useful to bear in mind how unlikely a white Christmas is on the law of averages.

According to Wikipedia (I know, I know...) "...at Dublin Airport, there have been 12 Christmas Days with snowfall since 1941 (1950, 1956, 1962, 1964, 1970, 1984, 1990, 1993, 1995, 1999, 2000 and 2004). The statistical likelihood of snow falling on Christmas Day at Dublin Airport is approximately once every 5.9 years. However, the only Christmas Day at the airport ever to have lying snow at 09:00 was 2010 (although no snow actually fell that day), with 20 cm (7.9 in) recorded". So we are up against it in terms of getting a white Christmas. Always.

And yet, I wouldn't rule it out just yet for 2016. At this stage, 12 days out, we can look more at the main models (ECM and GFs) for guidance and say thank you and see you next year to the CFS. Even at 12 days out though, the guidance you get from the GFS and ECM is limited.

The GFS firstly has been showing a clear trend over the last week for it to cool down midway through Christmas week (around 23rd) due to local high pressure and for it to stay cool / cold til New Year. All very seasonal so you would take that straight away. As it happens this morning's GFS is somewhat different however showing a more mobile, atlantic influenced, flow with, unfortunately, a very mild 24 hr interlude falling exactly on Xmas day. See below:-





Yuck.

The ECM only goes out to 23 December BUT, to the very untrained eye of yours truly, is more promising showing a potential rain to snow event for western and northern counties on the cards for 23 Dec into Xmas eve itself. Again it is atlantic sourced but there is a lot of colder air accompanying the system crossing the country that day. See images below and imagine what they might look like if the ECM went out a day more...





The difference in the two models though shows that nothing is remotely certain yet. To perhaps emphasise the point, these were the thoughts of the Netweather White Christmas Forecast 2 days ago - still about right...


"...2 weeks to go until the big day, and if you're expecting a more definitive view of the weather for Christmas, I'm afraid you're going to have to wait a while longer, as there is still a huge amount of uncertainty. In fact this is shaping up to be one of the trickiest Xmas forecasts for many years.

The reason is that the UK is set to be on or near to the battleground between blocking high pressure and Atlantic systems as we head into & possibly through the festive season. .......

At the current time, the most likely, but certainly nowhere near nailed on scenario is for high pressure to be nearby, meaning a quiet, mostly green Christmas, unless you want to say a frost is enough to claim a White Christmas!

The current uncertainty over the forecast for the festive period really shouldn't be underestimated though, so we could be set for a number of twists and turns as we move toward the 25th"

Anyway, as always, I will leave you with a seasonal image - this time its a picture of a field near Letterkenny on Xmas morning, 2010.

Well weather for the Christmas is looking interesting anyway! This morning's ECM and the latest GFS are similar showing a big storm brushing our shores on Christmas Eve. Alas in its wake I reckon some lucky few could end up with a White Christmas! See below.

The Xmas Eve storm looks like so:-



I will let others on other threads let you know how strong those winds might be, but that's a proper storm...

However there's very cold air mixed in with that storm so by late Christmas Eve the whole country is covered by -5 / -6 uppers:-



Which in turn gives us the rather salivating sight of snow showing up on the GFS precipitation charts like so-



and



So downside is a huge storm, but the upside could, just possibly, be a White Christmas for some.... (to enjoy by candle light possibly!):D

Merry Christmas from the 6z gfs (netweather chart)...



:):):):):):):):):)

Tonights ecm keeps up theme of Christmas eve snow risk, especially for higher ground. More western and Northern you are the better your chances.. ..

Probably easiest just to paste MTC's thoughts (see below). In short though, wind is the real headline but a White Christmas for some is still very much a possibility. Didn't think I'd be saying that just 5 days out..... The higher you are, and the more northern / western the better your prospects. As these wind systems come through they are going to drag down very cold air turning rain to sleet and snow.

"...SATURDAY (24th) ... Windy and cold, passing showers will become wintry and snow could accumulate on some northern hills, winds westerly 60-90 km/hr, temperatures steady around 3-5 C. Overnight (Christmas eve) it will stay very windy with temperatures slowly rising, any snow or sleet will change to rain and winds will become southwest 80-110 km/hr.

SUNDAY (Christmas Day 25th) ... Very windy with squally rain showers, temperatures peaking at about 10-12 C in south, 7-9 C north, during the morning hours (possibly before dawn), then turning sharply colder during the day with a return to mixed wintry showers as winds turn more to west-northwest at 80-110 km/hr. Potential for damaging wind gusts to 120 km/hr in exposed areas notably Connacht, west Ulster, and parts of west Munster, as temperatures fall gradually to 4-5 C. Snow appears possible at times on higher terrain if not more widespread...."

Odds on White Christmas have certainly lengthened in the last 24 hours as the storm track has moved north. Still a small chance for more north westerly areas later on Christmas day as temps drop. In fact MTC this morning was still holding out some hope...

"..SUNDAY (Christmas Day 25th) ... Very windy with squally rain showers, temperatures peaking at about 10-12 C, during the morning hours (possibly before dawn), then turning sharply colder during the day with a return to mixed wintry showers possible, as winds turn more to west-northwest at 80-110 km/hr. Potential for damaging wind gusts to 120 km/hr in exposed areas notably Connacht, west Ulster, and parts of west Munster, as temperatures fall gradually to 4-5 C. Snow appears possible at times on higher terrain if not more widespread. Strongest winds will probably occur when the temperatures begin to fall off around mid-day..."