FI Charts ( T120+ onwards) Autumn 2023 **READ MOD NOTE IN FIRST

Gonzo

September now less than 120 hours away so time to open the FI Autumn 2023 thread.

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Mod Note:

This thread is for posting/discussing/analyzing FI CHARTS ONLY i.e. Charts in the unreliable time frame, generally +T120 onward for Autumn 2023.

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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A new month, a new season and from the looks of things a new pattern change may well be on the way as we head from a very wet summer to perhaps signs of something dryer for the early part of Autumn.

First hint of a dryer pattern by 2nd September. Funny thing is it was 2nd September last year where we began a very wet autumnal pattern after the hot dry summer of 2022.

High pressure well and truly centered over us by the 5th.

IF this verifies this will be first genuine area of high pressure to influence our weather since mid June.

Deeper into FI the high shifts towards Scandinavia and we pull in a warm easterly from the continent. While this would make eastern areas cooler than the rest of the country the cooling effect from the sea breezes would be nowhere near as sharp as they were in May and first week of June.

We finish up with an area of low pressure from the Bay of Biscay trying to break down the warm and settled weather as we head towards mid September.

Temperatures on this GFS run getting close to mid 20s at times with low 20s quite widespread across the country especially if there are decent spells of sunshine.

Not a lot of rainfall over the first 10 days of September, very small amounts compared to what we've experienced all through July and various stages of August.

At the moment the models are looking good for things settling down with a warmer than average first half to September looking likely.

Meteorite58

So far HP looks dominant if a bit fragile the further out we get, currently looks like holding out any weather of note. Rainfall totals look small after tomorrow night/ early Thurs and at that not amounting to much in general. Models holding the warming trend from the weekend, currently looks to taper off later in the week. If we get the winds with that easterly component then possibly getting the best temperatures in the Western half of the country, into the low 20's perhaps.

squarecircles

Wow,that didnt last long,did it,back to pissing it down again by the end of next week and off we run into more gloom and misery.

https://www.boards.ie/discussion/comment/121049540#Comment_121049540

Hopefully it'll change back as quickly!

Gonzo

Models still look on track to deliver a lovely spell of warm and hopefully sunny weather through the opening 7 to 10 days of September, after that possibly turning cooler and more unsettled. Temperatures lifting up and taking off with mid 20s possible in many inland midland and western areas, low 20s closer to the coast and eastern areas. This shows up lovely on the GFS 12z ensembles.

Very little rainfall between now and the 10th of September, after that we may turn more unsettled but that is deep out in FI.

GEM is very similar, maybe a touch warmer than the GFS.

Later next week the high pressure may begin moving from anchored over us towards moving to Scandinavia, this may allow very warm south-easterly winds to flow our direction off a very warm continent.

A breakdown around 10th of September with low pressure from the Bay of Biscay possibly breaking down things.

Higher pressure then tries to re-establish itself particularly across southern areas.

By the end of this run we start getting much cooler and more unsettled but we're mid way through September by this point and i'll be heading to the Malaga region 2 days after this.

At the moment we are looking at a 5 to 10 day warm spell which will bring a lovely start to the autumn. The length of this warm spell is a bit uncertain, it may only last 5 to 7 days but could go beyond that. After such a poor summer we are very lucky to be getting this warm spell right at the start of September when summer style temperatures are still very much possible.

Medium range 10 day FI looks great... Like the June dry spell I feel this past week will be a distant memory. Ah well, great to get it.

Meteorite58

The charts certainly looking very unsettled , LP after LP, some very wet conditions if the models current output verifies, temperature gradients steeper as we move into Autumn, some blustery days and could see some very high rainfall accumulations. Temperatures up and down, probably some wild swings as LP move through. The jet looks to take a Southerly dive, mobile Atlantic.

gaa goes

It would appear that Ireland could experience Hurricane conditions the week after next. From Monday 25th September there are indications of stormy weather heading our way from the Atlantic. It will be very interesting how this storm will play out over the next 10 days or so.

Hooter23

It still looks like a Hurricane on the charts just to south west of ireland in 10 days time....moving at very fast speed in our direction too dangerous

Gonzo

Charts are looking very grim I have to say. We are heading into potentially a very prolonged unsettled period. These hurricanes may make their way towards us, several of them but they will be ex hurricanes by the time we get them, no doubt there will be plenty of wind and rain over the coming few weeks. While I am going away on Monday for 10 days I expect the current unsettled pattern to be still in place over Ireland by the time I get back.

Dazler97

This is hurricane lees track ,next week could be a stormy week ahead ,I posted this in the other thread accidentally apologise guys

PukkaStukka

I'm watching this one with concern. I'm travelling to the UK next weekend via ferry for an outdoor event on Sunday.

adocholiday

Just eh... Leaving this here

.Donegal.

Explosive cyclogenesis AKA a “weather bomb” day 9 to day 10 ECM. As always too far out to give it much thought at this point. IMO I think the potential is high for a named storm or 2 over the next 2 weeks.

.Donegal.

https://www.boards.ie/discussion/comment/121115297#Comment_121115297

I think that’s the highest modelled gust I’ve seen for us. Usually the modelled mental gusts are over a mountain range but never that high or extensive.

https://www.boards.ie/discussion/comment/121115297#Comment_121115297

Mostly offshore is the only good thing!!

sryanbruen

Yep autumn has gotten the foothold of any attempts at trying to get in more ridging as the zonal flow naturally strengthens this time of year and gets increasingly difficult to see high pressure.

A few weeks ago, I said MJO activity that was forecast would favour a build up in pressure towards mid-September. The heatwave was not that. The heatwave was purely the result of ex-hurricane Franklin amplifying pressure northward and the strong nature of the high pressure aloft allowed heat to build rather than it being advected northward from the south. It was more indicative of a summer spell than a September one. September is usually reliant on warm air advection so this is another aspect of the heatwave that was exceptional in my opinion.

The MJO activity, much like what happened in July, did not come off as forecast and has completely collapsed. This meant that without aid from hurricanes (which will come completely unforeseen on modelling output due to their tricky nature of forecasting), there is little chance of seeing high pressure return for a significant period of time. Sure the odd transient ridge in between fronts can never be ruled out but no more than a day or two with the Atlantic well back in dominance.

Others have mentioned this already but it definitely seems like this year we seem to keep alternating wet and dry after a few weeks, the wet Dec/Jan spell to the exceptionally dry late Jan and Feb to the wettest March on record followed by a rather unsettled April too to a mixed May but very dry second half up to mid-June then a changeover to unsettled with the wettest July on record continuing into much of August to the September heatwave to now this prolonged looking autumn unleashed spell. Nothing consistent about this year at all.

Carol25

Perhaps that storm will stay out in the Atlantic thus giving us less destructive conditions?

pauldry

Now it's further NW with a warm pull of air to end September that would bring over 20c for the final week.

Elmer Blooker

https://www.boards.ie/discussion/comment/121119519#Comment_121119519

Yes, reminding me of the beginning of Oct 1985 when the temperature got into the low 20s ….. after an appalling summer of course.

sryanbruen

The remains of Margot now looks like it could aid high pressure building by day 10 on the latest main two model runs. Did say these could pop up at short notice in model output given the nature of hurricanes. Doesn't look particularly warm at this point though this could change easily to something warmer or indeed back to unsettled.

I'm fed up of this muck already so hopefully we start seeing these signs become a trend.

Gonzo

High pressure over Ireland from the 29th would do me nicely! Last thing I want after 10 days in Spain is to return to weather like we've experienced over the past 2 days, cold, damp and wet.

nacho libre

It looks increasingly likely September will end on a settled note.

Elmer Blooker

fingers X , and may this continue well in October, all cold winters follow anticyclonic Octobers hence the old weather lore … ‘for every fog in October a snowfall in winter’

sounds ridiculous I know but so does the St Swithin legend which even some meteorologists admit has an element of truth to it.

gandalfio

So what date does this potential settled spell start on? Abd for how long is it predicted to last?

pauldry

Around 26th to 28th September will last into start of October if we are lucky but it will be getting dark by 7 then so no 27c days just 21c.

Meteorite58

The Atlantic becoming very active and turbulent, fast jet close to or over us, remnants of Hurricanes and tropical features in the mix, taking on a look of being very unsettled with some very wet days next week, remains to be seen if storms come close to us, will be watching for fast forming wave depressions being spun off the jet. Air temperatures up and down depending on frontal activity and position of warm sectors, some mid teens showing up at times, nights do look to be getting cooler getting down to single figures.

sryanbruen

Huge model wobble the past 48 hours alright, any attempts of ridging from the south gone just like that. Ah well that's the life of these hurricanes and tropical cyclones wreaking havoc with the NWP output. Sometimes they can hold in the Atlantic and allow ridging northward on their eastern side, we strike gold with a lovely spell of weather. Or they can add oomph to the jet stream and cause zonality. Autumn astronomically starting on Saturday morning so I guess it's only appropriate.

pauldry

The UK weather said a low pressure developing quicker off the coast of the Eastern US has delayed our High until later next week.

almostthere12

https://www.boards.ie/discussion/comment/121138610#Comment_121138610

It would be good to get a decent weekend out of it if it comes towards the end of the week.

Dazler97

https://www.boards.ie/discussion/comment/121138610#Comment_121138610

And if that's named believe it or not it will be ophelia , current models suggest it may make it a low end tropical storm but it will be a rain maker for the eastern seaboard of America, I'm keeping an eye on Tuesday for us as we could have our first named storm which would be Agnes (mrs brown lol ) that's nice