Storm Isha - Sunday 21/Monday 22 January 2024

Meteorite58

Thought it timely to start a thread to keep a focus on the possibility of a storm for next Sunday as we move under T120 . On the latest model runs shown as a fast approaching and rapidly deepening potential Storm system being powered up by a very strong and fast Jet ,currently tracking off the NW and getting down as low as 953hPa . Some models showing it to be quite windy the day before also. Good agreement from the main models of a potentially strong to severe wind event on sunday at this stage but as was seen over the previous few days it had initially been shown to be off the scale severe but has moderated some bit and could moderate more.

In general moving into a very mobile Atlantic regime from later Fri/ early Sat up until the following Weds or so at least with lots of warnings possible for both wind and possibly heavy rain in the Western side of the country at times, more so in Atlantic coastal counties where a high sea state could add to the risk of coastal flooding.

Some models showing Monday to be quite windy also and again for late Tues or Weds with another signal for very strong winds so can keep an eye here to see if there are other strong wind events being picked up by the models up to next Weds.

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Mod Note: This thread could get busy towards the weekend if a Storm materializes so your cooperation is greatly appreciated to please stay on topic, use appropriate threads and please adhere to the forum charter. Off topic posts cant be moved so will need to be deleted. Everybody is entitled and welcome to post on the topic. This is a thread for weather enthusiasts to discuss ,speculate and give opinion on the upcoming windy weather and post observations and relevant data in a civil and friendly manner.

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Meteorite58

The strengthening powerful Jet coming our way over the weekend into the following week being attributed to the temperature contrast over the US.

https://twitter.com/i/status/1747302799908499641

https://twitter.com/i/status/1747269742803779821

greasepalm

What do you reckon on with the winds Baltic temps here in Ireland

Meteorite58

https://www.boards.ie/discussion/comment/121627097#Comment_121627097

Temp a bit up on Saturday to around 8C or so, milder near coasts and becoming much milder Sunday possibly getting up around 10C or so in places, will fluctuate as systems and fronts go through , could have a touch of frost more towards Northern counties but some big swings to mild at times into the following week, seeing up to 10 or 12C at times.

littlema

If it is named.....will it be Isha, despite Irene going through The Lowlands at the moment?

DOCARCH

https://www.boards.ie/discussion/comment/121627273#Comment_121627273

Isha has an ominous ring to it! Can't wait for Kathleen. 😊

adocholiday

A lot of modification on the 00z runs this morning. It's quite a complex setup with a series of low pressure systems sitting over Iceland and the North Atlantic and most models now show rapidly developing spin off lows from this that are going to pack the punch. We had a similar setup with one of the stronger storms earlier in the season but I can't remember which.

The GFS for example shows it here, with the low starting to take shape late Saturday evening and properly formed when the strongest winds hit the West Coast 10 hours later

Most models are showing some variation of this but all still showing strong winds. It does look to be losing intensity again though, now primarily showing it to be a West Coast event with the rest of the country still getting strong gusts for a few hours.

ECM with the least intense outcome overall with this very much being a 50:50 event with the northern half of the country hardly seeing a breeze. Lots of change to come with this one I think.

Supercell

Don't like the look of the fax chart at all, long way out but looking nasty.

squarecircles

06Z GFS maintains the intensity of a severe nationwide windstorm.

squarecircles

further disturbed stormy weather next week ...

adocholiday

Where and when the two spin off lows form and merge is going to make all the difference. The 06z is a big upgrade on the 00z in terms of windspeed and if you look at the formation of the low impacting us in the 06z you can see the secondary low to its NW is much better formed and deeper than in the 00z. That's actually a secondary low itself, coming out of the parent low to the West of Iceland (which has been trending westwards itself on the models) and will have a significant bearing on how the low impacting Ireland will form. It's a very complex system of lows and secondary lows and I would think any charts showing wind speeds at this point can't be relied on. The timing and positioning of a low spinning out of a low spinning which is spinning out of another low has to be incredibly difficult to model this far out. Lowception. The word low has now lost all meaning to me.

Condor24

GFS, to me, takes Sundays storm off to Northern Scotland, missing us by and large, as it does next week for the following storm. Both nasty but far enough away not to cause trouble. That said, more runs needed to verify, it could change.

squarecircles

https://www.boards.ie/discussion/comment/121628322#Comment_121628322

Not sure how you are seeing that, The latest gfs would be a direct hit for the country, with high Orange/red alert level wind gusts for the west coast.

Robwindstorm

https://www.boards.ie/discussion/comment/121628184#Comment_121628184

I got a bit dizzy reading that 😁.

I agree with you. These lows often elongate as well as numerous centers so difficult to read. These storms of recent years tend not to develop into one defined structure like the 80s and 90s so it will be interesting to see what happens as all the ingredients are there.

WolfeEire

THE ECMWF panel for Sunday evening would suggest that somewhere from Clew Bay to Donegal Bay could be where the centre of this exceptionally fast moving system passes as it directs toward the western isles of Scotland. The strongest winds obviously being to the south of this line. In storm forecasting timelines, we are still a good distance out from the event so things will change.

Robwindstorm

Jeez Wolf, I got a bit dizzy looking at them as well.

These things don't seem to be able to be forecast just a few days out like back in the 'olden days'. I think as you alluded to before with the GFS, it can forecast weather types well in advance but maybe on the extreme side of what will actually happen. A hurricane force storm may turn out to be a very windy day or Gonzo's snow turn to a bit of frost. Interesting to see what happens with this event .

Cork2021

my take is it’ll be a miss. Any significant weather lately has gone pear shaped! I like a good storm but this will be a damp squib! The last two weeks of chasing snow has broken me 😂😂

weisses

Tuesday's system looks more potent

ascophyllum

Latest Arpege showing average wind speeds of 120+ off Galway on Sunday. That's average wind speeds. Gusts to 160.

Gfs and Ecm have it tracking much further south and less potent. GEM, Icon and WRF showing it affecting all western and maybe inland counties high level orange.

There's a load of energy coming across but it will probably be Sat morning before the models can show exactly where it will end up.

WolfeEire

The Arpege shows an incredibly dangerous storm. We won't be any the wiser until Saturday I would say.

Edit: Touche @ascophyllum

Cork2021

Country wide red alert with that

nacho libre

https://www.boards.ie/discussion/comment/121630301#Comment_121630301

The Arpege over did a previous storm if I am not mistaken. I think it's doing the same again, which, while I do like a storm, is just as well.

So I really doubt that will come off. I would be more concerned if either the UKMO or ECM were showing that.

nacho libre

.A big storm on the UKMO. Still plenty of time for this to downgrade,though.

Meteorite58

I agree ARPEGE most likely overdoing it at this stage as it is inclined to this far out, will come in to its own around Fri, very useful model all the same nearer the off.

ECM had given it a fair downgrade on the 0Z but back up again, widespread v windy up to about 90 to 100km/h overland, fairly long duration strong wind over Ireland for about 10 hrs or so.

GFS a bit different with two systems coming at us with speed, v windy in general gusting 90 to 100km overland , higher in some parts.

UKMO, well, its on the steroids again and is up there with ARPEGE with 160km gusts overland but a bag of salt with this for now.

ICON different shape , goes through a lot quicker but similar winds to the ECM and GFS if you take off about 10km/h that it normally adds on more than the others.

GEM and ACCESS-G showing some type of very strong windy weather but looks different to the others in timing and duration.

I think the ECM and GFS are a good bet to follow as a guide at this stage.

greasepalm

Just noticed the Headline date is a Mis Print as not 2023 ? should be 2024 with so few posts in it.?

Meteorite58

https://www.boards.ie/discussion/comment/121631112#Comment_121631112

Fixed , thanks for that, I'm really on the ball!😀

Meteorite58

..

https://twitter.com/i/status/1747710385149641197

Dazler97

Met Office already have yellow warning for Sunday about this storm

GFS doesn't seem too bothered about Sunday for now. Tuesday seems to be more significant if the 18Z plays out.

adocholiday

Still some big variations in the models. Quick summary of the 00z runs.

ECM: blustery for most from Saturday into Monday. Sunday not a particularly significant event with most parts of the country staying in or below yellow level gusts.

GFS: two different spells of high winds impacting us close together. First one shows winds picking up from 8am in the SW and W and as the storm moves up the coast winds will pick up across the country. Mainly yellow warnings or none for most other than coastal W and SW. Later that evening a much stronger system moves up and brings strong gusts to the southern half of the country. Orange level for some places south of a line from Galway to Dublin.

ICON: Similar to GFS but wider, stronger wind field for the first band and weaker for the second. Tends to overcook the max gusts so probably similar warning levels as GFS.

UKMO: A prolonged event but less intense. Landfall in the SW around 9am and windy across the country right through until the early hours Monday. Again nothing extreme, yellow overland and maybe orange for some coastal areas.

ARPEGE: Strong winds out to sea all day Sunday but nothing major overland, yellow warnings for coastal areas. However later Sunday night a band of very strong winds crosses the country showing widespread orange and red level gusts overland. Probably unlikely to verify.

All in all it's tempering on every run but still some changes ahead. I'd predict it's likely to be widespread yellow warnings with western counties possibly going orange for a time. I don't think we'll see red from this one personally based on the model trends for now.

GFS hinting at something now Sunday night going into Monday.

The Low for Tuesday seems to have pushed North a bit on this run.