[25 Oct-5 Nov] mild, sometimes windy and wet, weather with potential for disruptive rainfalls

M.T. Cranium · 25-10-2022 6:49am #1

There are going to be a number of marginal warning situations in coming days when strong Atlantic fronts arrive, both for wind speeds and rainfall amounts. It's more a case of an accumulating total rainfall that concerns me at present, with each system adding a new total of 15-25 mm. The latest GFS guidance changes in one regard, it has been featuring high totals along the south coast over 10-14 day periods, but now shows these pushing into the bulk of central Ireland in about a week's time (meaning that signals have emerged for stronger lows next week from a southerly source region). This thread can track the various events which begin with some strong winds and briefly heavy rainfalls tonight and Wednesday (northwest coasts could see gusts around 110 km/hr). A more widespread and active frontal passage is set for Thursday night into Friday morning and could be quite strong for the east coast as a strong southerly gradient develops. After that, it's a case of monitoring the ever-changing details on a parade of further lows that seem to be lining up for as long as the upper level flow will tolerate them, at the moment there are no strong signals of this ending and one system in particular that may evolve into something different, but timed for early next week (into the first or second of November time frame).

The current GFS output shows central Ireland at 120 mm total rainfall within 8-9 days, but about half of that seems to be reserved for a system towards days 7-9 so this could change. It is a new signal compared to previous runs. As I mention in the forecast discussion, rather high sea surface temperatures over the Biscay region following the hot summer of 2022 could feed energy and moisture into any lows that form down that way and which then move north towards Ireland. But before this potential heavy rainfall we have about three active systems coming along in more of a southwesterly flow that will, if not producing flood potential directly, set the stage for any later heavy rain to become problematic. This is the peak rainfall portion of the year, and I think it was Nov 2009 when that potential was most realized across parts of Ireland and northwest Britain.

pauldry · 25-10-2022 10:46am

Yes indeed MT. November 2009 we had 279mm of rain in Sligo. Leitrim had over 300mm and Carrick was flooded for the whole month. Wev had 122mm in October and Markree is over 150mm so if your prediction is right we will pass 200mm. I think February a couple of years ago, 2020 we got 240mm up here. That was the wettest I remember in past few years. This Southerly source of rain is a disaster as it keeps feeding pulses of heavy rain and with all the leaves it promotes flooding.

Gonzo · 25-10-2022 11:04am

I don't think I have ever seen a GFS 10 day precipitation chart as wet as this mornings one for overall coverage of 100mm+ of rainfall.

Flooding and disruption is bound to happen over the next 10 to 14 day period. There is also the possibilities of more thunderstorm potential next week.

giveitholly · 25-10-2022 12:33pm

Recorded over 185mm of rainfall here in tipp in September and already up to 175mm for October

Gonzo · 25-10-2022 1:20pm

GFS 6z is even more over the top with rainfall, predicting up to 175mm of rainfall for some western areas over the next 10 days.

November is looking increasingly unsettled well into the month, could we be on track for a re-run of the November 2009 floods?

Wanderer78 · 25-10-2022 1:34pm

shite, and i wanted to go camping next week!

pauldry · 25-10-2022 2:24pm

Probably another 100mm in most places the next 2 weeks. Some dry spells in between the heavy rains too so it might feel OK at times.

Coastal stations of the West and South could get over 150mm more

By the by Gonzo where do I get those charts for Accum Precip?

Graces7 · 25-10-2022 2:38pm

https://www.boards.ie/discussion/comment/119791372#Comment_119791372

My house is kind of perched on a raised concrete base... Where that ends a moat develops between concrete path and gate. I learned why my first winter here and am deeply appreciative..

West Mayo offshore

Danno · 25-10-2022 3:16pm

Getting fed up of this rain now - Luckily the mid-month of September was dry. Think five or six weeks of this is enough for any soul to bare.

Graces7 · 25-10-2022 3:42pm

There is nothing optional unfortunately.

odyboody · 25-10-2022 3:51pm

https://www.boards.ie/discussion/comment/119790996#Comment_119790996

Hmm, Its what followed the floods I'd be waiting for.

pad199207 · 25-10-2022 4:00pm

https://www.boards.ie/discussion/comment/119791859#Comment_119791859

The frozen floods

Graces7 · 25-10-2022 5:38pm

That does it. Hibernation definitely calls...

Gonzo · 25-10-2022 5:39pm

https://www.boards.ie/discussion/comment/119791372#Comment_119791372

Visit the Meteociel website https://www.meteociel.fr/modeles/gfs/royaume-uni/precipitations/3h.htm

click GFS with the UK flag and then in the options click the Accu. precipitations thumbnail and that will show you the precipitation totals over 10 days for Ireland and the UK.

Cluedo Monopoly · 25-10-2022 11:27pm

The Shannon is rising.

Athlone station.

Realtime waterlevel

M.T. Cranium · 25-10-2022 11:47pm

The 12z and 18z GFS output is a little less dramatic for total rainfall potential, but this could go in cycles for a few days. The reason for the downgrade (if 70-90 mm can be called that) is no particularly strong low to follow around 1-2 Nov from a southerly direction. It could return to the picture though.

One wave of rainfall has pretty much come and gone in the past six hours, with some downpours in various locations. A stronger south wind will develop overnight and it could get briefly rather blustery on the Mayo coast around 0300-0600h. That will relent gradually during the morning and the next wind maximum looks like being mostly for the southeast coastal areas around midnight to 0300h Friday early morning, with a sharply defined front heading for Britain, could produce a broken squall line feature for south central and eastern counties during the night (Thursday night into Friday morning).

Nothing too dramatic shown for following days but the 12z GFS prolonged the mild signal and had some fairly energetic looking systems as far out as 8-10 November.

Graces7 · 26-10-2022 5:47am

Just normal autumn weather! We had such a lovely spell....

Graces7 · 26-10-2022 6:54am

And it has morphed into a loud, violent morning. Everything that can be moved outside has been ...relocated.

And it gets worser and worser and some of the guttering is loose now. Shaking and rattling...

Hard heavy rain.

Welcome autumn!

West Mayo offshore

DOCARCH · 26-10-2022 7:09am

A heap of rain overnight in Greystones. 37.4mm since yesterday afternoon.

Oscar Bravo · 26-10-2022 7:21am

A gust of 61 knots(113km/h) at Mace Head on the 7am met reports. Stormy along the Galway/Mayo coast

Graces7 · 26-10-2022 7:31am

https://www.boards.ie/discussion/comment/119794047#Comment_119794047

Indeed it is. Stormy.. Tempestuous. Sudden bellows of gale sound... ... Hoping the power holds ..It is the gusts that tend to do the damage

West Mayo offshore

M.T. Cranium · 26-10-2022 8:17am

So after its pause the GFS model has returned to a very stormy outlook 1-2 Nov, which would return the total rainfall to the more extreme values as well as providing risk of locally very strong winds. Track is from SSW to NNE through the midlands. European model has the development a bit later (more like 2-3 Nov) and approaching from southwest. GEM has not detected anything intense but shows the larger scale pattern (this would not be the first time GEM took its time catching up).

Usually if you have cross-model convergence on a solution by day five in these situations, you've got an actual storm and not a model fantasy session, the timing fits my research model also. Already two or three jogs in the road to the actual outcome but to give some idea how gradually models have been responding to this stormy signal, there were charts a week ago showing cold northeast flow and sleet potential in early November. The strength and duration of this mild spell were poorly handled in the longer range charts available mid-month. So the trend is towards more development, of course that could over-correct at some point.

Graces7 · 26-10-2022 9:03am

It is always hard to assess the first storms.- from a layperson;s viewpoint - after a period of such deep calm as we have just enjoyed.

Initial assessment from a simple resident. is of considerable ferocity. A day to take great care. ie stay inside when living so near the ocean. Just a field away at the back here.

A steady strong wind is less potent and damaging than this fiercely gusting gale. I learned in my first winter here to respect utterly this phenomenon. I opened the door as a gust hit and was literally flung bodily across the concrete path almost to the stone wall.

Now the door is safe;y anchored so it cannot swing out like that.

Please take great care out there.

cheezums · 26-10-2022 1:56pm

Early morning Friday looking pretty wild.

Graces7 · 26-10-2022 2:01pm

easing a little for now. Bright sun! What St Patrick ( The Lorican) referred to as " The whirling wind's tempestuous shocks" have eased somewhat. For now...

JanuarySnowstor · 27-10-2022 4:51pm

Disruptive rainfall due tonight with possible lightning through midland areas.

Surprised not a orange warning for rain

Oscar Bravo · 27-10-2022 5:44pm

Status Orange - Rain and thunderstorm warning for Leinster, Cavan, Monaghan, Tipperary, Waterford

Met Éireann Weather Warning

Heavy rainfall with embedded thunderstorms likely to cause flooding.

Valid: 23:00 Thursday 27/10/2022 to 07:00 Friday 28/10/2022

Issued: 09:44 Thursday 27/10/2022

Updated: 17:15 Thursday 27/10/2022

pad199207 · 27-10-2022 5:46pm

Not surprised. The air is thick with moisture out there. Very humid.

Oscar Bravo · 27-10-2022 5:47pm

Heavy rain corresponding to warning

JanuarySnowstor · 27-10-2022 5:54pm

https://www.boards.ie/discussion/comment/119801159#Comment_119801159

Cork missing eventhough an onshore southeast gale coupled with high tide means only one thing for the morning imo

JanuarySnowstor · 27-10-2022 7:36pm

The extreme stuff showing up on the radar to the South of Ireland. It should show its hand over the South first after midnight. Looks extreme to me and likely to cause a lot of surface flooding as it moves North.

I differ to Met Eireann in that the orange alert should be for Munster and Connacht, not further East!

Let's see what happens!

dsmythy · 27-10-2022 8:03pm

Dublin uses shield.

Not sure how the downriver shield is though.

pauldry · 27-10-2022 8:12pm

No I agree with Met. After midnight we might see an hourly report of over 20mm somewhere

pad199207 · 27-10-2022 8:13pm

Looks Soggy

CirrusBusiness · 27-10-2022 8:31pm

Going to be bad flooding with this. The ground is already like a bog.

Robwindstorm · 27-10-2022 11:04pm

The east was bound to get flooding with this current set up of depressions coming up from Biscay giving easterly winds as well. As I said on a different thread a while back, the east has not seen major flooding in a decade and the law of averages usually balances itself out. After the hot summer of 1995 (like this year), there was an exceptionally mild October, albeit dry, but early November brought spectacular thunderstorms and flooding. And as someone posted earlier, what happened after the floods, frozen floods. On side note, I'd say Gonzo is like a kid on Christmas Eve waiting on a thunderstorm tonight.

adocholiday · 27-10-2022 11:15pm

Met Eireann not forecasting anything too crazy for South Wicklow on their hourly forecast. Yellow rather than orange based on the numbers, with a short lived duration. Wonder how it will compare to reality.

pad199207 · 28-10-2022 12:28am

Status Yellow - Wind warning for Dublin, Louth, Wexford, Wicklow

Met Éireann Weather Warning
Very windy early this morning. South to southeast winds, veering southwest, will reach mean speeds of 40 to 55 km/h with gusts of up to 100km/h possible.
Valid: 04:00 Friday 28/10/2022 to 07:00 Friday 28/10/2022
Issued: 00:24 Friday 28/10/2022

M.T. Cranium · 28-10-2022 6:26am

Mullingar reported 40 mm of rain overnight, Ballyhaise still adding to about 37 mm. More like 10-20 mm in the Dublin region where the squall line has recently passed. Winds turned westerly and gusted to 83 km/hr. The next event is Saturday morning's likely heavy rainfall moving north through much of the country, although there could be isolated thunderstorms later today after the brief clearing comes and goes.

DOCARCH · 28-10-2022 7:59am

On Met E radio forecast mention of almost 50mm recorded in Clonmel.

Got off a bit lighter this time in Greystones with only 6.8mm since midnight.

cml387 · 28-10-2022 8:30am

https://www.boards.ie/discussion/comment/119802955#Comment_119802955

The River Suir is now heading for it's median flood level according to the OPW, of course since the flood relief scheme there is no longer any town flooding

Rock Lesnar · 28-10-2022 8:31am

Thankfully only 7.2mm in my area of county meath, expected a lot more then that

Chris_5339762 · 28-10-2022 12:00pm

17mm since midnight in Cork, but my system underresponds in windy conditions as the rain sensor is also up the pole.

pauldry · 28-10-2022 1:19pm

Only 14mm in Sligo

146mm for the month.

Quite a bit more in Markree.

Over 170mm for October there.

Dazler97 · 28-10-2022 3:25pm

I'm surprised Cork isn't under water like it used to

pauldry · 28-10-2022 5:17pm

Up to 155mm in Sligo now

Two very heavy downpours today

Places are bound to be at or near 200mm by November 1st

giveitholly · 28-10-2022 5:53pm

https://www.boards.ie/discussion/comment/119805238#Comment_119805238

Gone past 220mm here in tipp already

Darwin · 28-10-2022 6:33pm

According to my local water level monitoring station, last night's rainfall put my local river (Whitehorse) half a metre over the median flood level. It's within 0.44m of the highest flood on record (1963). I've never seen the river this high, bit worrying to think there is a lot more rain to come next week.

M.T. Cranium · 28-10-2022 7:44pm

Is that in Cork? Can't find a White Horse river, just a pub in Ballincollig. But wherever it is, GFS has fairly moderate rainfall amounts through next four days, it would be around days 5-7 that heavier rain returns to west Munster. Over the period from now to 12z Sunday, 10-15 mm amounts are shown in the south and west, less elsewhere. That gradually doubles over days 3-4 to 2nd Nov. Then a further 30-50 mm depicted for west Munster 3rd-6th. Eventually 130 mm for parts of west Munster by 7th (47 mm shown close to Dublin). In the week to follow that, heavier rain is more evident across the north which catches up to west Munster in terms of total rainfalls, both reach 150 mm by 13th Nov. (Dublin shown at 84 mm by then, about 70% above normal for that many days).

Darwin · 28-10-2022 8:53pm

No in Leinster MT, the White Horse river is a tributary of the river Nore (I'm based in Laois)

Danno · 28-10-2022 10:48pm

https://www.boards.ie/discussion/comment/119805581#Comment_119805581

Mountrath territory!

[25 Oct-5 Nov] mild, sometimes windy and wet, weather with potential for disruptive rainfalls

Comments

Status Orange - Rain and thunderstorm warning for Leinster, Cavan, Monaghan, Tipperary, Waterford

Status Yellow - Wind warning for Dublin, Louth, Wexford, Wicklow