Potential Storms Thursday and This Weekend -19 & 21/22 November

pauldry

Very sad to hear about the accident. Sympathies with their families.

As for the storm lets not get too alarmist. It may be a storm but broken branches and power cuts of a couple of hours will be all that will bring hopefully and anyways nearly always these storms become much smaller babies closer to the event. The GFS is just a cycle of WCS.

Deep Easterly

Daily rainfall total up to midnight finished at 26.4mm, with 22mm of that falling in the last 5.5 hours. Rain much lighter now. Temp is down to 5.1c which is quite cool for a rainy night!

Storm 10, did you get to record your rainfall totals today? I would say you could have got close to twice as much as I did this evening.

maquiladora

Totally agree, this is only a model run and there is no need to be alarmed right now, but it is an extraordinary run and we should at least be aware that something like this is even possible in a few days time, not in FI.

Ill be staying up to see the 0Z run come in and hopefully it will be a downgrade.

garytuohy

crazy circular rapid burst lightning over howth at the moment??????

maquiladora

The 0Z run is out and worryingly there is no downgrade yet, in fact it looks more intense than before...

M.T. Cranium

It is a sobering set of maps on the GFS run, that's for certain ... but if the other major models are right, the weekend will just be windy, nothing too extreme.

If the GFS is right or close to being right, then a dangerous and damaging storm will develop on Saturday. The gradient indicated in many parts of Ireland exceeds 60 mph sustained and would produce gusts of 80-120 mph, I would think, depending on how exposed any location is to a strong SW wind.

Those are such extreme values for the country as a whole, sure a place like Malin Head might see winds of this strength once or twice a winter, but exposing the whole country to such winds would be potentially a very severe event.

Nobody should panic at any point, of course, but at this stage, I should stress that the storm is only a 50-50 sort of risk at worst; the GFS has been known to over-deepen lows even at this time range, but what's worrying is that the locational difference from the other models (further east) explains the pressure difference (larger energy budget from the warmer Biscay waters).

We're all going to be waiting to see if the models converge on one solution and who was closer to being right at this early stage -- and if by Thursday morning this intensity of storm is still on the maps then it would all change to a very urgent time of preparation -- because these winds could do serious damage and would expose a lot of predictably exposed people and their property to harm. This is where some preparation could take place regardless, as people could easily do an inventory -- look around their locations and property, assess what would happen if trees or small buildings suffered serious damage and fell in a predictable direction (towards the northeast), then what else would get damaged, and how much of that could be prevented (for example, by choosing carefully where to park a car).

Then if the storm does hit, people won't be scurrying around in foul weather trying to secure things at the last minute. Don't want to sound preachy, I'm sure people in some parts of Ireland are more used to strong winds than most people on earth, but I foresee the risk of this storm affecting larger areas including large towns and cities where people aren't as used to dealing with strong winds (and where there are more trees -- it's a truism that extreme storms do a lot of tree damage because they hit areas that support more trees, and trees that have matured without seeing a similar wind event).

All things to consider, and then if this storm fizzles out, people would be ready for some future storm of a similar type (they might not have long to wait either).

And don't overlook the fact that some south coast locations could be seeing rather severe gusts at times on Thursday morning. (possibly SSW g to 70 or 75 mph).

Anyway, if this flops, don't blame us weather "weenies" -- we don't produce these computer model charts, we just try to tell people what they would imply about the weather. I've seen enough deep storms to be quite sure that this one, shown as a 948 mb low at mid-day on Saturday, would be capable of producing extreme gusts and long periods of very strong sustained winds too. A very similar looking low that really happened about 30 years ago in eastern Canada had winds strong enough to blow over large hydro-electric transmission towers. Winds can reach cat-2 hurricane intensity in deep lows of this shape and size.

Betcha now that I've said all this, the 06z GFS will have a weak little low far away from Ireland ... so maybe I should say some more. :cool:

Redsunset

Missing all the fun due to work,just finished and heard on radio on way home that part of tuam road closed.corrib has burst its banks.Cars are submerged underwater too

maquiladora

M.T. have you seen the UKMO chart? http://www.wzkarten.de/pics/brack2a.gif
What do you make of it?

force eleven

Met Eireann still hedge their bets,yeaterday the weekend was very windy, now they say gales on Saturday. But stopping short of the word 'stormy'. They'll wait and watch to see of the other model forecasts agree with GFS, as it is out on its own at the moment with this weekends events.

As MT says it is 50-50 at present.

maquiladora

Met Eireann are right not to jump the gun on this, and if it does come to pass, well the forecast for "gales" will be accurate anyway.

Anyway, the 06Z will be rolling out soon. Will be interesting to see if the GFS keeps the intense storm or downgrades/shifts it.

alibabba

As a noob here, thanks for the updates, they really are appreciated.

Drove into work this morning, galway, by god i never saw such deep flooding on the roads ever.
I didnt think the car would make it thru some of them.

Is that the end of it or are we looking at more for the weekend ???????

I read a report a few pages back of armegeddon weather for ireland ?????

maquiladora

Looking at the 06Z run...the storm doesn't stay alive as long on this run...the track looks very similar to the last 2 but a small downgrade overall.

pauldry

Just a tad worried now after seeing UKMO Model. Surely theyr right. But the centre of these secondary lows have minds of their own and it is still Worst case. 14.6mm of rain in Sligo so far since 1930 17/11. Light rain at present.

pauldry

06Z on www.wetterzentrale.de shows a slight downgrade:)

maquiladora

Met Éireann weather warning for Thursday ( too early for any warnings for Saturday yet) :

Weather Warning

Issued at 18 November 2009 - 10:03

Heavy Rain Warning

Further very wet and windy weather expected Wednesday night and through Thursday with widespread rain and strong southerly winds.
Rainfall totals of 20 to 40mm in many areas, with falls of 50 or 60mm likely in parts of the southwest and west with some severe flooding likely.
Southerly winds gusting 80 to 110km/h in some exposed places .
Clearer weather will spread eastwards on thursday night.

mike65

Looks scary enough to me (live images)

alibabba

dont think i'll get to work without the boat tomorrow morning

mad DIY

alibabba wrote: »

dont think i'll get to work without the boat tomorrow morning

N17 flooding pics - Let's all keep going until someone gets stuck... I don't recommend !

That could be me tomorrow if the rain is as bad as predicted, I have an appointment with some country boreens prone to flooding

maquiladora

Met Éireann giving fair warning on tonight/tomorrow's rain event :

Further rain in all areas tomorrow - probably wet for much or all of the day, heavy falls in many areas. Flooding possible almost anywhere, but with Munster and Connacht particularly at risk.

In the UK, the MO has issued Red "High risk of extreme weather" warnings for the NW of England for Thursday, talking about rainfall of "up to 250mm" for parts "accompanied by severe gale force winds".

And this is just for Thursday....

squonk

When is the next GFS out? I'm starting to get excited about Saturday although after the events of the past 24 hours ont he roads it's a frihtening thought also.

forkassed

mike65 wrote: »

Looks scary enough to me (live images)

Do those wind feather things show sustained winds?

As in 85kt off the waterford/wexford coast

85kt being equal to 100mph?

maquiladora

squonk wrote: »

When is the next GFS out? I'm starting to get excited about Saturday although after the events of the past 24 hours ont he roads it's a frihtening thought also.

Will start rolling out at 3:30. It'll be interesting to see if there is another downgrade for the weekend storm. Have to expect plenty of chopping and changing with these type of events though, hard to predict even hours before they arrive.

maquiladora

forkassed wrote: »

Do those wind feather things show sustained winds?

As in 85kt off the waterford/wexford coast

85kt being equal to 100mph?

The barbs show sustained winds, yes. Gusts would be higher.

The first chart is the windspeed at 10 meters up, the second chart is the windspeed at about 1,500 meters up in the atmosphere, not on the surface.

greysides

maquiladora wrote: »

The barbs show sustained winds, yes. Gusts would be higher.

Is there any way to predict the speed of gusts from the 10m wind speeds?

Deep Easterly

Great pics Alibabba. Not the first time I've seen that particular spot submerged and I doubt the last time either.

Dosen't look like the rain is too far off once again here in Chooom. The sky darkening with racing scud clouds from the SW. Warming up though nicely with temp at 12.8c currently.

maquiladora

greysides wrote: »

Is there any way to predict the speed of gusts from the 10m wind speeds?

I think M.T. or someone here more knowledgeable than me might be the best person to answer that, but I think gusts can be about 1/3 higher than the sustained wind.

Sierra Oscar

UK Met Office have some "Take Action" alerts out.

North West England:


Rain will become very heavy and persistent early on Thursday and continue until Friday morning. Rainfall accumulations of 50-100mm are expected quite widely, with up to 250mm possible locally over high ground. With this amount of rain falling onto saturated ground there is a high risk of localised flooding.

The rain will be accompanied by severe gale force winds.

The public are advised to take extra care and refer to the latest Environment Agency, Floodline, and Flood Warnings in force.

The public are advised to take extra care and refer to the Highways Agency for further advice regarding traffic disruption on motorways and trunk roads.

Issued at: 1235 Wed 18 Nov

http://www.metoffice.gov.uk/weather/uk/nw/nw_forecast_warnings.html

Nothing for Sat yet though.

jd

When I left home today I noticed that that the lake in northwood (fed by santry river) is barely 9 or 10 inches below its banks on the swords road side. If it floods over its banks swords road won't be much fun tomorrow...

mad DIY

Meteoalarm gone red for Wales, up to 120mm rainfall predicted. If they get that much, is there a possibility we can get that much ?

force eleven

mad DIY wrote: »

Meteoalarm gone red for Wales, up to 120mm rainfall predicted. If they get that much, is there a possibility we can get that much ?

Wouldn't take much more rain to cause severe flooding in places where it is prone to happen...next batch of rain now fringing into Connacht and not far from Kerry and Clare. The problem will be that it doesn't want to clear away eastwards as would normally happen. The fronts are going to 'oscillate' westwards and eastwards slowly, and when you are under that situation, you will get a hell of a total amount of rain. If you are prone to flooding, I would already have the sandbags in place....

And then we have Saturday....I would wait until the other computer models have this storm much nearer the northwest coast before getting overly concerned. We will have a pretty good idea what to expect by this time tomorrow with a better degree of certainty than right now.