FI Charts ( T120+ onwards) Winter 2022/2023 READ MOD NOTE IN FIRST POST

WolfeEire · 18-12-2022 12:28AM

The mean temps for Christmas are colder on the 18z GEFS compared to the 12z owing to a building of heights from Greenland and a subtle shift southeastward of the Euro high. We can expect a growing cluster of colder members when the ensembles come out, when compared to 12z. A solid bet would be average temps for time of year for Christmas but we are edging closer to a trend for colder than that. Mild conditions not as favoured in the ensembles. Again, Monday eve's runs (36 hours after the arrival of the Sunday low) will bring greater clarity to everything.

You can see upper air temps up to Christmas Day in the 18z. You will see the op run is the mildest of the 30.

sicknotexi · 18-12-2022 01:06AM

https://www.boards.ie/discussion/comment/120008858#Comment_120008858

I was going to post this to outline the drop in temperature around Christmas Day but that is much better.

Rebelbrowser · 18-12-2022 09:41AM

All the models this morning still show an attempt at a northerly incursion on Xmas Eve / day with differing successes. Largely concensus is it will be pushed back by the HP over Europe but far from certain. ECM the worst for Xmas day itself

Rebelbrowser · 18-12-2022 01:12PM

6z GFS has a very cold few days from 26th to 28th with temps dropping throughout Xmas day. Seasonal certainly.

Gonzo · 18-12-2022 01:41PM

It's very low level cold tho, The GFS operational has daytime temperatures around the 2 to 8C range during this period before going back to double figures again on the 29th. We may get a frost out of this on 1 or 2 nights but looking at the charts this morning there won't be much if any snow or disruption, unless we see serious model changes tomorrow or early Tuesday. However at least it will feel somewhat more seasonal than 13C and sideways drizzle.

The GEM is much colder than the GFS, but something isn't right about the temperatures they are predicting, a bit like last Monday the GEM was predicting daytime temperatures last Friday to be around -8C which of course never happened.

WolfeEire · 18-12-2022 01:50PM

A colder set of members for 24-27th in the 00z compared to 12z but more seasonably cold than very cold weather for Christmas, as @Gonzo and @Rebelbrowser say. The op run was on the extremeties of the milder members for Christmas Day itself Still, a fairly consistent trend away from a very mild Christmas for most of the island. Let's see how today's complicated system and the high pressure areas interact now. Tomorrow evening will provide a much clearer picture of next weekend.

Hooter23 · 18-12-2022 02:27PM

The charts look like they will change for next friday/saturday..but which way will they go will decide what the christmas weather will be like...anything is still possible by the looks of it..

icesnowfrost · 18-12-2022 06:00PM

Charts really struggling to make their mind up but still interesting reading. I think they will start merging towards a colder Christmas Eve Christmas Day and st Stephens but how cold will be the thing. Obviously a snow covered Christmas Day would be fantastic but it’s probably not going to happen.

all eyes on the charts over the next few days and by Wednesday things should be very clear. Famous last words 😂❄️❄️❄️❄️❄️

WolfeEire · 18-12-2022 06:09PM

The trend towards a cold Christmas certainly continues. The ICON, which was not really entertaining cold up to now, is now showing some interesting charts.

SleetAndSnow · 18-12-2022 06:12PM

GFS not looking like a big outlier either from what I can see? I'm on mobile though so the lines can be closer.

Gonzo · 18-12-2022 07:04PM

The GFS 12z does get very cold for 2 to 4 days from Christmas Day, we get -10 uppers into Leinster and Donegal with plenty of frost.

Christmas Day temperatures close to freezing across the country.

Similar on Stephens Day

Tuesday 27th perhaps the coldest day of the cold snap if these charts verify.

Wednesday and Thursday also look quite cold temperatures 2 to 4C across the country and then a big warming trend from the Friday into New Years weekend.

The GFS 12z has some support for this level of cold but it is on the coldest range of the set, but overall we have seen a further swing to cold.

The GFS ensembles also suggest a very wet period in the second half of this week just before things turn colder and drying out considerably once the cold air is in place.

The GEM and UKMO both say no to Christmas cold so will have to wait and see if they fall in line with this GFS run tomorrow or will we be back looking at mild charts tomorrow but this GFS ensemble run is certainly encouraging. Just checking the GEM ensembles which are still rolling out and it looks like the GEM operational is a warm outlier, the majority of the GEM runs sends temperatures tumbling on Christmas Day.

mcburns07 · 18-12-2022 07:18PM

Would absolutely take it right now.

Gonzo · 18-12-2022 07:26PM

GEM ensembles are certainly encouraging for at least 2 to 3 days cold, however quite a few of them have us on a knifes edge with very warm air just off our south coast but we are in the cold for the most part. There are quite a few GEM members doing something similar to the chart below.

Overall I'm happier about this afternoons runs than I have been in several days, certainly a step in the right direction. Will the ECM actually show something cold over the next 30 minutes, we may have to wait till tomorrow for that.

edit: ECM is another mild run. ECM hasn't had any interest in cold for several days now.

Oneiric 3 · 18-12-2022 08:27PM

It seems that it isn't only us in Europe that can become frozen by Siberian air. Almost all the the N. American continent is about to experience a potentially historic blast of it towards the Christmas period. 😲

https://www.youtube.com/watch?v=yaRf4pesoVg

Danno · 18-12-2022 08:35PM

https://www.boards.ie/discussion/comment/120011862#Comment_120011862

Thats not good for us if we want a dead Atlantic.

Oneiric 3 · 18-12-2022 08:52PM

https://www.boards.ie/discussion/comment/120011887#Comment_120011887

All depends. That cold air mass is poised to exit the very SE US, which could help in triggering more southerly tracking Atlantic lows. Personally though, I wouldn't mind some proper lively Atlantic weather.

Gonzo · 18-12-2022 09:11PM

Another thing that may go against us the PV looks poised to ramp up in January as the weak to moderate warmings that have been keeping it under pressure in recent weeks is set to go away as we enter January.

PV now:

PV early January.

The AO also looking to go from strongly negative to neutral or slightly positive by early January.

NAO also set to go weakly positive.

Danno · 18-12-2022 09:45PM

https://www.boards.ie/discussion/comment/120011999#Comment_120011999

Oh yet another mild January looks on the cards, apart from 2021 - recent Januarys have been terrible for cold wintry weather.

nacho libre · 18-12-2022 10:23PM

https://www.boards.ie/discussion/comment/120011948#Comment_120011948

A big North Eastern storm could also lead to a ridge towards Greenland. Although with the Strat' and Trop' Polar Vortex set to connect it looks bleak for notable cold in January, as the blocking will disappear if it happens . So you will probably get your wish for a mobile Atlantic. We can only hope in that scenario systems are on a North West to South East axis to draw in colder air after systems pass through. As regards Christmas, let's hope the GFS is correct, but I'd not be confident given the ECM and UKMO have other ideas. I guess we will have a fair idea about what's going to happen over Christmas by tomorrow evening.

.Donegal. · 18-12-2022 11:57PM

GFS snow starting in the North this Friday

Substantial fall by Christmas morning in Donegal,Derry,Tyrone and Fermanagh.

By lunchtime Christmas Day most of the country has a covering

By 7pm Christmas Day practically all of the country has seen snow for the big day

Gonzo · 19-12-2022 12:29AM

GFS 18z appears to be a cold outlier, almost on it's own. Still rolling out and there may be a slight swing back to mild overall, but hard to tell at this early stage.

Meteorite58 · 19-12-2022 01:37AM

ECM and GFS couldn't be more different in the end result, the GEM is more like the ECM : S , SW driven Lp systems and quite active out to +240hrs , more on the milder side with some cooler incursions, GFS as .Donegal . posted above much colder brisk outflow from from the Arctic winning out and goes on to develop a large Atlantic ridge with a HP centered over Ireland and collapses the Jet thus prolonging the cold spell . There is a brief break in the Jet by the ECM too at around +210hrs but it keeps the LP's in charge in the our neck of the woods keeping the bulk of the coldest weather at bay. Jet powering up over the US at the end of the run heading our way.

GFS back in the freezer with wintry weather , snow, very severe frosts over snow fields and ice days . On the current run has plenty of frontal triggers associated with LP's coming in from the W, NW to produce the wintry stuff.

ECM showing Gales , possibly a bit windy on coasts and generally around 8 to 10C by day and maybe a touch of frost in Northern counties at times.

GEM similar to the ECM, bit cooler at night, was showing the very colder airs but not as much on the latest run.

I can see how the GFS wins out with the cold Arctic air getting entrenched over us but can also see how the ECM would win out with the more active LP train.

The weather forecast after the news tonight did mention uncertainty around the weekend.

ACCESS-G , Australian model ,more like the ECM and GEM . ICON as said above has gotten a lot colder around the Weekend on the latest run but UKMO also more in line with the ECM, GEM and ACCESS-G.

Would be inclined to lean more towards the milder, windier scenario based on todays and previous days flip flopping, but will have to wait for another couple of runs to see if the GFS could cause a big upset ?? 😀

Rebelbrowser · 19-12-2022 09:08AM

Just looked at about 5 different models this morning. So many differences! But the big three do favour cold Xmas night into Stephen's day. Ironically GEM is no longer our favourite model showing no such cold uppers for Ireland

PokeHerKing · 19-12-2022 11:49AM

GFS 6z has us going back in the freezer for new years on a nice easterly feed🤞

200motels · 19-12-2022 11:51AM

The latest GFS is like the pub run, I can't see this happening, if it did, well it would be brilliant from Xmas day onwards.

SleetAndSnow · 19-12-2022 12:01PM

GFS is very pub run ish this mornin with its 6z, but caution that the mean has the euro high slightly stronger then it did on the 0z so all to play for still.

UKMO and ECM seem to have moved towards the GFS a bit more this morning, UKMO broke down afterwards but ECM is showing some sort of cold now compared to last time. GEM doesn't seem to having any of it, yet. Crazy model watching, and Christmas is starting to near the non fi thread! @Rebelbrowser will be up the walls with the white Christmas thread given how all over the place the models are 😁

WolfeEire · 19-12-2022 12:08PM

GFS 06z ensembles look cold as does UKMO.

Gem op run was a very mild outlier. The mean is not very cold but it's a degree or two below the IMT. ECM the same. Would hope that the 12z runs will bring some form of closer agreement between the models. The setup is very complex and extremely hard to call. We are heading into sub 120 hours chart territory.

Gonzo · 19-12-2022 12:08PM

The 6z could probably be binned as nice to see a deep easterly far out into FI, we first have to get the potential for cold weather over Christmas sorted. At the moment the models generally are favouring a mild and Atlantic driven Christmas period and the GFS is a bit on it's own with the Christmas cold. The GEM and it's ensembles look close to a 50/50 split between a cool to mild Christmas vs a properly cold Christmas. I'm not sure the 12z models today are going to be enough to be certain about next weekend, we may need into tomorrow afternoons runs to see where we are at.

edit: The GFS 6z is completely on it's own with zero support.