FI Charts ( T120+ onwards) Winter 2024/2025 **READ MOD NOTE IN FIRST

Gonzo

Mod Note:

This thread is for posting/discussing/analyzing FI CHARTS ONLY i.e. Charts in the unreliable time frame, generally +T120 onward for Winter 2024/2025.

If your post does not specifically relate to an FI chart then it doesn't belong here - Off topic posts will be moved

Thanks

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Winter is finally here! The opening first 2 weeks of December appear average to mild in terms of temperatures. At the moment not much in the way of excitement in the models. We look to be mostly Atlantic dominated and mild with a chance of high pressure building at times.

It could become fairly unsettled towards the end of next week with possibly strong winds.

On this particular run high pressure tries to make a move towards us but never really gets there, instead we have winds coming around the high from the north-west.

Winds turn northerly very briefly allowing much colder air to stink southwards over us for a limited time.

The northerly quickly gets cut off and we go back to a mildish North-westerly airflow.

.Donegal.

It’s a potent Northerly. Just 282 hours away

Gonzo

That potential northerly is transitional and is a big outlier based on the 18z ensembles visiable by the thick green line on it's own around December 13th.

It's unlikely we will see anything genuinely cold over the next 2 weeks but the window of opportunity probably will widen during the second half of December, perhaps a cold snap over the Christmas holidays. In terms of precipitation not much over the next few days but then a fairly wet period mid week to Friday and then relatively dry again after that, so nothing overly wet.

Gonzo

Probably a very wild outlier but for what it's worth the Can't Forecast Snow model is going for a weak easterly developing soon and arriving over us in a weeks time.

This then develops into a northerly with a bitterly cold airflow.

As I said at the start this is probably an extreme outlier and also it's the CFS so a huge dump load of salt required for this. Very unlikely to verify but it would deliver a mostly dry and very cold and seasonal early season cold spell with probably ice days on offer.

Gonzo

What is more likely to verify is after a mild, wet turn second half of this week, we turn gradually colder over the weekend with a north-west to south-east alignment to the jetstream, keeping us cool, but not overly cold in any way. Possibility of wintry showers on north-western hills perhaps next week and quite windy at times making it feel fairly cold.

Once we get the 3 to 4 days wet period out of the way this week things look cool from Sunday onwards with temperatures perhaps a degree or 2 below average and some showery conditions with perhaps night time frosts in sheltered areas.

Gonzo

UK Met also now toying with a cold spell beginning next week, we could be mostly high and dry and frosty much of the time.

Winds into the north-west at the weekend, but uncertainty in the models regarding a low which the UKMO brings into France instead of the UK and Ireland.

Winds go into the north on Sunday, cold and plenty of unbroken sunshine.

North-easterly flow by Monday but high pressure influencing our weather, maybe a few wintry showers across the south-east.

It wouldn't take much adjustment to move that area of high pressure further north, then we would be under more of an easterly, so we could be looking at a prolonged cold spell setting up as soon as next weekend.

On another note this mornings GFS 6z is also playing around with the potential for a major warming as we head towards Christmas, plenty of interesting stuff in the models today!

bazlers

https://www.boards.ie/discussion/comment/122918067#Comment_122918067

https://x.com/BigJoeBastardi/status/1863955886869250358?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Etweet

Larbre34

We don't entertain Joe Bastardi around here. He's a spoofer.

Ros4Sam24

Gfs pub run in FI, so usual caveats apply. Have heard some lads across the pond giving a chance for cold from 18th onwards. We live in hope

icesnowfrost

15 or so days away but there are some small signs of going cold from the 16th been showing that for a day or so now. Need to keep upgrading.

Kermit.de.frog

Some tentative hints appearing of a change in weather pattern that could lead to something a good bit colder in the not too distant future but a long way to go yet. It's too early to go in to much detail with a lot of cross model flux but I'd be focusing on these pressure rises to our north and slowing of the jet stream we're seeing emerge across the models from day 4 - 7 in various guises.

almostthere12

https://www.boards.ie/discussion/comment/122927583#Comment_122927583

Yes indeed, the models are beginning to show some very interesting scenarios but as you mentioned nothing showing very cold at the moment. The MJO is predicted to move into phases 6 and 7 later in the month which I believe is good for blocking in our neck of the woods and also there are hints of a potential warming taking place which if we were very lucky could be the first signs a SSW is an option.

nacho libre

I have a feeling this could be boom or bust- we either get a notable cold spell or it all goes pear shaped and we end up with something smiliar to what the seasonal models have suggested. As long the pv doesn't get its act together over Greenland we are in the game

Billcarson

Hope it doesn't end up like Christmas 2021. When it looked like a fairly reasonable chance of some sort of cold spell and then it all was a complete bust. Don't want to be lead up any garden paths.

brookers

https://www.boards.ie/discussion/comment/122927583#Comment_122927583

Any updates?

Kermit.de.frog

https://www.boards.ie/discussion/comment/122936901#Comment_122936901

Not positive for cold weather fans on this occassion. It looks like back to square one zonal westerlies by next Monday and nothing exciting in between ☹️

icesnowfrost

always at the end 😂 still some signs of a cold spell trying to develop. Interesting chart watching ahead.

esposito

Had a quick glance at the charts this morning. They’re rubbish. Looks Atlantic driven up to Christmas. What a surprise… Are we ever gonna get a cold Christmas again? :(

Things can change of course and maybe just maybe late December/ early January might deliver for cold weather fans. Frosty, sunny weather will do nicely if we can’t manage to get snow.

Gonzo

Charts are a nightmare in the run up to Christmas with winds from the Canaries next week, usual story. A mild Christmas is very likely again this year. At the moment there is not a shred of interest in the models between now and the end of December with Atlantic dominance and mild or very mild charts. December is likely to finish up substantially milder than average, and it will be the first month to do so since the prolonged run of colder than average or average months from June to November.

mcburns07

Oh come on, Christmas is two weeks away. Why do people take charts that far out seriously?

Gonzo

https://www.boards.ie/discussion/comment/122944122#Comment_122944122

For me theres several reasons, one is we seem to be in the same setup every December with the exception of 2010 obviously. The run up to Christmas is almost guaranteed to be mild in this country, we seem to get the winds up from the Canaries almost every single December just before Christmas or mild long fetch south-westerlies, this is the form horse for our part of the world most Decembers. The vast majority of Christmas build up periods over the past 12 years or so have mostly been mild, damp and sometimes stormy and rarely does it get genuinely cold.

Looking at the NAO/AO forecast over the next 2 weeks there is very little support for both to go strongly negative, they look like staying either neutral or slightly positive so Northern Blocking is unlikely to be a key player over the next 2 weeks for our part of the world so zonality is likely to stay with us. The very much warmer than average North Atlantic sea surface temperatures ain't helping things either.

A minor to moderate warming is taking place in the stratosphere across Siberia but this is unlikely to have much impact on the PV other than displacing it very slightly and is unlikely to affect or disrupt the weather patterns in any way.

Of course things can change over the next 2 weeks as forecasts are unreliable beyond 4 to 5 days but at the moment I don't see a huge swing to genuine cold for Ireland this side of Christmas. Perhaps things will become more interesting as we progress towards New Years Eve or sometime in January.

WolfeEire

The ECMWF must have been out for Christmas drinks with the GFS pub run. The op run showing this evening is unlikely to receive significant support in tonight's ensembles, but there is some support for higher pressure to be in Ireland's proximity during the Christmas period based on the 12z GEFS.

.Donegal.

Christmas morning

WolfeEire

Met Eireann, in its extended forecast, is pitching for settled but rather benign conditions over the Xmas/New Year period and into the opening week of January. Wintry showers "cannot be ruled out" and there "is a possibility of colder/frostier nights and lingering mist/fog during the days"
https://www.met.ie/forecasts/monthly-forecast

Condor24

Look away from the current GFS if they're the horse you've stuck cold and snowy money on for Christmas. As of today, looking like a westerly blast all the way from Newfoundland around the big day. Deep low pressure around Iceland, strong high pressure at the Azores. Might be a stormy one. Hoping for a 180 flip in the next two or three days, still time, but the trend is your friend as the say, or your enemy perhaps. This contradicts Met E. in Wolf's post above highlighting the uncertainty two weeks out.

esposito

https://www.boards.ie/discussion/comment/122945155#Comment_122945155

I really don’t pay much attention to Met E long range outlook. Didn’t they admit themselves that they are unreliable? The form horse as we know for December is mild wet and stormy unfortunately.

Hope to god we get at least settled weather over Xmas period but highly unlikely I would say. Very happy to be proven wrong!

A really cold January would be nice. Last one was 2010 and that was just the first 10 days or so.

Jan 2013 we almost hit the jackpot but we were just on the wrong side of marginal.

JCX BXC

https://www.boards.ie/discussion/comment/122945388#Comment_122945388

In fairness, it's not just that their long range forecast is unreliable, it's that all of them are. I wouldn't discount it over other sources.

Models still don't have a perfect grasp on how the weather actually works in fairness. Even last night, only a few hours out, the low temperatures were drastically higher than forecast.

WolfeEire

There is a reasonable number of much colder solutions cropping up on this morning's GFS ensembles. I will be looking at the ENS over the next days to see what they are leaning toward. I expect the mean temp in the ENS to drop somewhat from where it is right now based on the current trend.

I think the chances of a blowtorch Christmas period are minimal and that the form horse is a cooler polar maritime airflow as suggested by @Condor24.

Gonzo

Models overnight look as flat as a pancake as I've ever seen, zonal westerlies all the way between now and end of December with the cold locked up in the artic circle. Hopefully we will begin to see more interesting charts appear before the end of the month in time for January.

Gonzo

Just after I posted the above the GFS 6z rolls out and goes fairly cold for Christmas Day and Stephens Day with a brief northerly followed by a cold high, this is probably a cold outlier.

A dusting of snow in places with an ice day on the 27th on this particular run.

Milder air returning by the 28th.

When the 6z ensembles completes this will probably be very much an outlier.

Rain from the West

Impressive cold plunge on Stephen's Day evening, but it doesn't last for long.