The 13th Annual Boards White Christmas Thread (Christmas 2022)

I suppose its been a week so just to update. CFS still the only game in town at this remove. Seems to have a funny set up with the atlantic blocked save for a big low pressure system trapped over us. Would be very wet in the lead up and a bit drier on the day with temps of 5c to 10c. Meh but not mild per se. See below

Below of course is what we are looking for - its Dublin from Christmas week 2010.

Apologies for radio silence - stupid work getting in the way.....

Anyway, just a quick update. Just over 1000 hours to go so things are (quite literally, unfortunately) hotting up. The CFS shows as follows today:-

So not a hope of snow with those temps. Will do a proper update in the coming days....

Well, the long term charts continue to give little to cheer for those of us seeking a White Christmas - though I know on different threads there is discussion of changes in the upper atmosphere that might help to alter that. For now though the CFS is showing a mild, pleasant Xmas day as per below, with High Pressure in charge...

The GFS is still quite a bit away from assisting in terms of covering the Xmas period, let alone the other models. Met Eireann do give a monthly forecast on their website which presently goes out to 22 December. The most recent forecast for the final week of that period is a little more encouraging, stating:-

"...Week 4 (Friday 16 December to Thursday 22 December)

 Week four is fairly natural usually signifying a transition and low confidence. But with the predominant picture showing low pressure to the northeast and weak high pressure to the southwest a northerly airflow looks most likely. Temperatures will be close to average and a likely showery set up would bring slightly above average rainfall to Ulster and below average rainfall to Munster. Potential hazards in this period grow slightly with the northerly airflow likely bringing some winter mixed precipitation and frost potential at night...."

Just to give context, the last widespread White Christmas (falling snow on the big day), was in 2004. So what did the charts look like that day? Thanks to TheWeatherOutlook I have pasted them below. A polar airflow off the north north west was the catalyst for beefy snow showers for many that day. 18 years on, we are overdue something similar!

Very few photos online of the 2004 snow. I've attached one below from the Wicklow mountains, but it was snowing at sea level in much of the country (including my part of the world in Cork). There are a few videos on youtube, one of the Sligo snow in 2004, but won't link here. Til next time...

Well, it's here, the day we finally say goodbye to the CFS and start looking at the main weather models. Only the American Global Forecasting System (GFS) goes out to 25 December yet, so we will focus on it. And it is saying....that it will be a cold Christmas but no snow presently forecast. It shows the following 2 metre (what we experience) and upper atmosphere (where our weather generally comes from) temperatures at 7am on the big day...

Not bad, very seasonal anyway.

That said, MTC this morning is calling for a mild Xmas days with westerly winds so not all good news.

Keep the faith folks...

When I typed the above message yesterday there were still the key frames of the 12z GFS to roll out, but I "just knew" what they were going to say. So I posted that message. a possible white Christmas was around the corner and all was well with the world. Since then that GFS did not show what I wanted for xmas day when it concluded 10 minutes later and the 18z, 0z and 6z GFS runs that followed were even worse. Moreover the ECM has been similar. Basically all have backed away from the idea of the return of any proper cold after this Sunday's breakdown. There may be a cold interlude next Tues / Wed but nothing like the present cold. On the plus side, that brief interlude is slightly more likely to provide some snow than the current largely dry spell. Xmas day still not clear but there are some worrying signs of the mild wet muck we usually get.... 11 days to go though so still far from resolved.

So what caused this turn around in forecasts? Was it some unforeseen US storm with onward consequences for our weather? Was it an area of High Pressure over Europe not properly accounted for? Was it some global weather influence like La Nina? People will have their views. I know in my heart and soul though that its because I posted when I did. I couldn't just wait, oh no.... Never tempt the weather Gods.

Maybe reverse psychology is the way to go!

Just to give the actual state of play, the most recent model run, the 6z GFS (American model) shows Xmas day being very seasonal and pleasant with HP firmly over the whole island. Dry as a bone, afternoon temps of mid single figures with frost on both Xmas Eve and Xmas night.

The other models go out to midnight on Christmas Eve and, in general, the ECM (Euro model) shows a LP system to the SW bringing milder air and probably rain - but the trajectory of that LP suggests it might slide away to the south of the country and if it does that it will drag down colder air in its wake for Christmas night and onwards. Lastly the GEM (Canadian model) is our current favourite as it shows an LP system to our NE dragging down cold polar maritime air which could, just could, give snow for some - western half of the country favoured. Not long lasting probably but we in the White Christmas thread aren't picky how we get snow! Possibly similar to Xmas day 2004 for those who remember it.

Charts below.

So, as you see, lots of options still on the table.

Just to update, Christmas day weather still up in the air (though I suppose all weather is...). A few models show some decent cold from 25 to 27 December, others don't. Snow is still a possibility certainly (though as always in Ireland odds are against). Some great analysis by, especially, WolfeEIre and Gonzo, in the 120 hours plus thread.

Out of laziness I'm just found to cross post WolfeEire's excellent post from the t120 thread here. Odds against but, well, you'd never know..

"................Decent GFS ensembles for festive cold weather from Christmas Day afternoon through the 27th. Wintry showers for counties in the northwest and west on Sunday evening into Monday. Largely dry with sunny spells elsewhere.

12z GFS still giving hope for a (technical, at worst) White Christmas somewhere on our Isle. GFS snow charts are famously inaccurate and tend to predict snow far too often, but still with keeping an eye out here. See below.

Bottom line is we aren't getting a big freeze up this Christmas as had seemed possible but we are getting very shortlived cold for a few hours on Christmas night that could possibly give snow to a few. I'd take it, as that is ultimately what this thread is about...

18z GFS similar for Christmas night..

MTC's forecast for tomorrow:-

"...CHRISTMAS DAY (Sunday 25th) will bring more showers although there might be a few brighter spells too. Turning somewhat cooler from the northwest during the afternoon. Highs 8-10 C south and east, 7-9 C west and north. Some showers could turn sleety or wintry over higher parts of the north and west during the night (25th-26th), as lows drop to the 2-4 C range...".

So a very small chance yet for very select areas, eg. the NW, but unfortunately it's far more likely that we go yet another year without a White Christmas....

Let's see though.

Desperate times call for...

According to the post pasted below, Casement recorded snow at 9pm in reports. Think that means it was officially a white Christmas?

Donegal

Posts: 188 ✭✭ 25-12-2022 8:45pm edited 10:00PM

8pm Casement recording sleet and Dublin airport recording rain.

Edit Casement recorded recent snow at 9pm.