The Week Ahead - Discussion - Potentially Storm Thursday

Su Campu

I think the strongest winds will be for a time on Wednesday evening/night, just ahead of the surface warm front.

ninebeanrows

Will turn windy again in the east as the mature cyclone pushes south across the country this evening.

Showers will begin to pepper the coast with a few TS's and hail possible along with gusts to 50mph.

Wednesday a storm depression bombs south of Iceland and heads north of Ireland and into Scotland.

Strong gradient to the south of the storm will spread gales and storm force winds for the northwest and north coasts.

Exact track of low subject to uncertainty, exhibits characteristics of extreme storm system with intense gradient, so it is an extremely dangerous storm and must be monitored.

If pushed 100mph south would pose great risk to Irish mainland.

Storm early Thursday


Storm Thursday evening

ninebeanrows

Su Campu wrote: »

I think the strongest winds will be for a time on Wednesday evening/night, just ahead of the surface warm front.

Snap:D;)

mickger844posts

Surprised your saying Wednesday Su, the models are pointing more to Thursday/Friday. Why Wednesday evening/night??

leahyl

OOOH are things looking up again lads?:D

Deep Easterly

As Maq & Su have pointed out, could be windy later on in the week. Latest ECMWF has a tightening gradient developing of the NW coast on Thurday which could bring the risk of gales to northern areas especially:



In no way a definate, but could be one to keep an eye on.

leahyl

Deep Easterly wrote: »

As Maq & Su have pointed out, could be windy later on in the week. Latest ECMWF has a tightening gradient developing of the NW coast on Thurday which could bring the risk of gales to northern areas especially:


In no way a definate, but could be one to keep an eye on.

Cool....and here we go again:)

WolfeIRE

The models have been fairly consistent on this since Friday of last week.
They have had and continue to have the system tracking eastwards over Scotland. Strongest winds most likely to be seen in the northern two thirds of the country, with the SW escaping the worst of the winds. Gusts of 45-50 knots are likely with sustained winds of between 35-40 knots for a time. This is based on latest model output.

ninebeanrows

WolfeIRE wrote: »

The models have been fairly consistent on this since Friday of last week.
They have had and continue to have the system tracking eastwards over Scotland. Strongest winds most likely to be seen in the northern two thirds of the country, with the SW escaping the worst of the winds. Gusts of 45-50 knots are likely with sustained winds of between 35-40 knots for a time. This is based on latest model output.

UKMO has the low developing slower and later thus tracking a decent stretch further south, the UKMO chart is of concern and any further developments would warrant a warning. 0z models will be crucial in determining whether issuing an early weather advisory is necessary.

maquiladora

Posted this is another thread but....



Strongest winds highlighted there, so if the centre of the low was further south it could be quite stormy in places.

As it stands now though, based on the 12Z GFS.....



Gales / Strong Gales possible down along the northeast, east and southeast coastal areas.

Worth watching but these lows tend to drift further to the north by the time they come around!

Su Campu

mickger844posts wrote: »

Surprised your saying Wednesday Su, the models are pointing more to Thursday/Friday. Why Wednesday evening/night??

I was looking at the 00Z FAX charts and the tightest gradients were ahead of the system. I must admit I haven't looked at later runs.

weisses

That's a pretty low system ... 950mbar they won't get much lower then that are they ?? :eek:

maquiladora

weisses wrote: »

That's a pretty low system ... 950mbar they won't get much lower then that are they ?? :eek:

Becky/Last night's low was only about 9 hpa higher than that. The difference is not just that this has lower pressure but it has a better core structure and tighter isobars. It's not a flabby one. :P (On this model anyway)

Oh, and the storm of 1839 was 918.

http://en.wikipedia.org/wiki/Night_of_the_Big_Wind

Su Campu

maquiladora wrote: »

Becky/Last night's low was only about 9 hpa higher than that. The difference is not just that this has lower pressure but it has a better core structure and tighter isobars. It's not a flabby one. :P (On this model anyway)

Oh, and the storm of 1839 was 918.

http://en.wikipedia.org/wiki/Night_of_the_Big_Wind

I think Becky leveled off at around 956hPa in the end.

maquiladora

12Z GME looks a bit more nasty.

Deep Easterly

maquiladora wrote: »

Oh, and the storm of 1839 was 918.

http://en.wikipedia.org/wiki/Night_of_the_Big_Wind

Bring that on!

maquiladora

12Z NAE has the centre of the low a bit further SE than the GFS and UKMO at 48 hours.

nacho libre

if the latest ecmwf chart were to verify - then gusts of 60-70 mph possibly could occur in the extreme north and northwest of the country.

ninebeanrows

nacho libre wrote: »

if the latest ecmwf chart were to verify - then gusts of 60-70 mph possibly could occur in the extreme north and northwest of the country.

is the 12z out yet?

Can't see it myself and this thing is on the upgrade.

12z will ramp it up SIG compared to the 0z i would of guessed.

nacho libre

Weathercheck wrote: »

is the 12z out yet?

Can't see it myself and this thing is on the upgrade.

12z will ramp it up SIG compared to the 0z i would of guessed.

no it isn't. i was basing it on this chart posted earlier:

sorry for the confusion.

isle of man

so i could expect the same as last night for this then.

after seeing the mess this moring i think the winds in places were well over 80mph.
a 8mtx4mt shed with rsj in it . not bolted to the ground was flung 8ft up and over a hedge!!!!.
and 66mm of rain in 24 hours!!!!!!!!

maquiladora

12Z ECM is an upgrade alright...

ninebeanrows

ECM is very similar to the GFS

No need for alarm as the Low is just far enough north to leave the severe winds just to the north but still impacting the northwest and north coast.

Although the low would trek eastwards from there for a closer impact.

maquiladora

Yep, very similar at T72. ECM looks a bit more intense than the GFS but pointless to microcompare them at this stage.

Now if the track started to trend a bit further south...

maquiladora

isle of man wrote: »

after seeing the mess this moring i think the winds in places were well over 80mph.
a 8mtx4mt shed with rsj in it . not bolted to the ground was flung 8ft up and over a hedge!!!!.
and 66mm of rain in 24 hours!!!!!!!!

See, I told ya the Isle of Man would get some strong gusts!

ninebeanrows

Bucketing rain here, could last a while with the set up.

A clap of thunder too.

isle of man

maquiladora wrote: »

See, I told ya the Isle of Man would get some strong gusts!

yes you did, and thank you:D

Su Campu

Those beefy showers dropped 17mms in 12hrs at Shannon Airport and 13mms at Valentia today.

TheMilkyPirate

M.T. Cranium wrote: »

UPDATE _ Monday, 2:15 p.m.
________________________

Kerry and Cork are getting the lion's share of convective showers this afternoon with chance of hail, thunder and heavy downpours causing spot flooding. Otherwise, the expansive "eye" of the storm is over Connacht now and drifting southeast. When the easterly flow arrives late this evening and overnight, expect to find rain spreading back into eastern counties from the Irish Sea and quite a bite to the wind where it comes directly in (30-45 mph), otherwise a moderate increase to 20-30 mph for most parts.

Just a quick question didn't want to clog MTs thread. He says late this evening/tonight for the eastern county rain, I've to que for black ops at around midnight tonight (:D) would it be here by then would you think or will it be into the morning?

EDIT: 700th post! Only took me 4 years lol

delw

baraca wrote: »

Just a quick question didn't want to clog MTs thread. He says late this evening/tonight for the eastern county rain, I've to que for black ops at around midnight tonight (:D) would it be here by then would you think or will it be into the morning?

EDIT: 700th post! Only took me 4 years lol

started raining here already,bring an umbrella,im sure it be worth it


edit:congrats on 700th post

Deep Easterly

Tonight's ECM, if anything, has increased the forecast windspeeds for Thursday:



Full gales now in coastal areas ( strong gales in the NW and north) with possible gale gusts overland during heavy showers especially. Let's hope it will deepen even further in later runs.

Edit, just to add for those who may not be 'regulars' on boards.ie weather, please take charts this far out with a colossal pinch of salt. We are only speaking of possiblities here at the moment. We will know what the story is, for better or for worse, closer the time.

pauldry

Deep Easterly wrote: »

Tonight's ECM, if anything, has increased the forecast windspeeds for Thursday:



Full gales now in coastal areas ( strong gales in the NW and north) with possible gale gusts overland during heavy showers especially. Let's hope it will deepen even further in later runs.

Edit, just to add for those who may not be 'regulars' on boards.ie weather, please take charts this far out with a colossal pinch of salt. We are only speaking of possiblities here at the moment. We will know what the story is, for better or for worse, closer the time.

Yes DE the flabby part of the Low will hit us instead of the lines

Oh dont you love my weather knowledge.

Anyways in all seriousness I think this low is going North and its effects on us will be "normal" wind and rain

On another subject I swallowed some high gloss paint today and got electricuted yesterday and I still live. Some immune system Sligo people have.:)

Lumi

pauldry wrote: »

I swallowed some high gloss paint today
got electricuted yesterday

Pauldry - you can't leave us hanging like that - details please!! :eek::D

maquiladora

Deep Easterly wrote: »

Tonight's ECM, if anything, has increased the forecast windspeeds for Thursday

Yep, it certainly has DE.

Here is a closer look.



Not often you see ECM ramping up a storm more than the GFS but that is the case herel Centre of the low is further south and those isobars look nicely stacked.

Definite strong gales on the coasts and gales inland in parts there methinks.

maquiladora

CMC 12Z is a cracker.

Gales/strong gales on the coasts and inland in the NW at T78 and then at T84...



Gales and even strong gales inland in the east/southeast and storm force winds on the east coast.

Have to remember though...its only a model.

Su Campu

The 18Z HiRLAM has it reaching a minimum pressure of 948hPa at midnight Wednesday, which is the lowest of the models.



The ECM has a bit of a wobble in the track of the centre between 12Z and midnight Wednesday, which brings it on a track slightly more towards us as it deepens further, but it looks like Wednesday afternoon gales will start occuring along Atlantic coasts, moving to the Irish Sea after midnight, followed by some stronger winds for Thursday, increasing through the day, becoming strong gale force to storm force along Atlantic coasts, strongest in the northwest, where the trailing occlusion could be near enough to enhance gustiness. Overall, all areas will get winds as strong, and in some cases, stronger, than yesterday, and for a longer duration.

A lot of variables yet that could change things. The low spawns from a deep cutoff low currently over the US east coast, and gets caught up in an as yet unformed jet that forms Tuesday night as a blast of low thicknesses shoots down from Baffin Bay. This jet will be around 50kts weaker than the one over the weekend, but its peak strength coincides with the surface low located in its left exit region, which causes that wobble and further strengthening during Wednesday. A slight change in the exact dynamics of the formation of this jet could cause enough of a change to the surface deepening to affect its rate of occlusion and hence its track. As occlusion occcurs, the low will tend to track to the left, away from us. But the models seem pretty consistent with this system, and there's no reason not to have full confidence in them, especially after they handled Becky so well.

And for any journalists reading - THIS WILL NOT BE A HURRICANE!!!

km79

what kind of rainfall can be expected from this? i cant remember the last dry day :eek:

maquiladora

Su Campu wrote: »

And for any journalists reading - THIS WILL NOT BE A HURRICANE!!!

Hopefully after the Becky/Tomas fiasco the media will ignore this.

ninebeanrows

18z for what it's worth pushed this abit further south as compared to its 12z.

Pushes a tight gradient south through southern Scotland, Northern Ireland.

parths of Northwestern England/ Wales, look set to be battered as indeed Northwestern Ireland in particular.

Central pressure progged at ~950mbar

Su Campu

km79 wrote: »

what kind of rainfall can be expected from this? i cant remember the last dry day :eek:

A band of moderate rain will race across the country Wednesday night, bringing around 20mm on average. It will clear to blustery showers for Thursday, heaviest in the northern half of the country. Possibly longer periods of rain in the far north from the back bent occlusion

maquiladora

18Z GFS is indeed an upgrade on the 12Z.

Gales/strong gales in many coastal area from the NW around to the SE if that came off, though inland winds would probably not be a lot higher than last night in most places.

Still needs to come further south a bit more though...

TheInquisitor

Harps

What direction will the wind be in west Donegal? Supposed to be getting a ferry on Friday so north or north west winds will put an end to that

ninebeanrows

maquiladora wrote: »

18Z GFS is indeed an upgrade on the 12Z.

Gales/strong gales in many coastal area from the NW around to the SE if that came off, though inland winds would probably not be a lot higher than last night in most places.

Still needs to come further south a bit more though...

Yes for anything really severe we need another 100mile push south on the GFS and another 50-70 miles on the UKMO.

Deep Easterly

This system is entering hi res territory on the 18z runs. Here is what the 18z HIRLAM is showing (subject to much change in later runs) for 0000utc Thursday:

Cloud forecast:



Front crossing Ireland with a classic swirling low to the northwest.


Wind forecast:



Tighening gradient south of the Atlanitc depression with gale to strong gales surging forth!

nacho libre

maquiladora wrote: »

18Z GFS is indeed an upgrade on the 12Z.

Gales/strong gales in many coastal area from the NW around to the SE if that came off, though inland winds would probably not be a lot higher than last night in most places.

Still needs to come further south a bit more though...

but in reality, as alluded to earlier, it's more likely to track further north than what the models are currently showing. in any case it's a timely reminder just how difficult it is to get a proper storm to effect most of the country these days. so, as was mentioned earlier, anyone new to the forum, who lives inland, don't get your hopes that you'll see windier weather than last night you likely won't. i could be wrong, though:)

M.T. Cranium

This one appears to have loads of potential for developing strong winds on Thursday, and I don't see the usual tell-tale signs of a northward drift in track, if anything, would be watching for the opposite drift here, but the 18z GFS and 12z GEM (CMC) both show the core of strong winds right over northwest Ireland about 12-15z Thursday. Would say there is potential from these charts for sustained 55 kt winds with gusts to 80 kt at places like Belmullet and Malin Head, that would probably imply 40 gusting 60 over most of inland Connacht and Donegal unless well sheltered, and direction of these strongest winds would be 240 deg (WSW).

The potential further south drops off a bit, however it would probably generate 45-50 kt gusts even in the southwest and along the south coast, and 50-55 kt gusts in Dublin.

Rainfall potential (from about 2100h Wed to 1200h Thurs mostly) appears to be 20-30 mms with the heaviest falls across central Ireland.

Temperatures during the strong winds would peak around 11-12 C then fall off to about 7-8 C by late afternoon Thursday, so not much potential for snow on hills, but probably some hail showers mixed in especially in the colder WNW flow that wraps around late Thursday.

Just another random comment, the whole 18z GFS run past Friday looks very chilly, I would estimate the mean "IMT" or "CET" values near 3.5 C from all that blue lurking nearby -- and the entire sector from eastern Canadian arctic to central Russian arctic looks very cold throughout. This tends to argue for potential snowfall events down the road.

maquiladora

nacho libre wrote: »

but in reality, as alluded to earlier, it's more likely to track further north than what the models are currently showing. in any case it's a timely reminder just how difficult it is to get a proper storm to effect most of the country these days. so, as was mentioned earlier, anyone new to the forum, who lives inland, don't get your hopes that you'll see windier weather than last night you likely won't. i could be wrong, though:)

Oh I know. Ive seen enough of these curve away to the north as we get closer to crunch time! But the trend at the moment has been a southward drift on the models, and the the models performed very well on the rather unusual track of Becky at an even earlier stage than this storm.

Deep Easterly

maquiladora wrote: »

and the the models performed very well on the rather unusual track of Becky at an even earlier stage than this storm.

Very true Maq, but that unfortunely does not necessarily mean that they will perform as good this time, but I am hoping (as we all are I guess) that they are onto something!

nacho libre

maquiladora wrote: »

Oh I know. Ive seen enough of these curve away to the north as we get closer to crunch time! But the trend at the moment has been a southward drift on the models, and the the models performed very well on the rather unusual track of Becky at an even earlier stage than this storm.

well they have that's true and hopefully they won't do about turn. i tend to be pessimistic in my outlook anyway, as i don't like to get my hopes up only to be left disappointed. my attitude is probably quite annoying if you're an optimist

maquiladora

18Z GFS ensembles for Dublin :



Even though the 18Z was an upgrade the mean had lower pressure at the peak of the storm and only 2 or 3 ensemble members had higher pressure than the operational run.

Wouldnt be surprised if it tracked a bit further south on the 0Z going by that!

So far so good lads.