Damaging winds Thursday 13:00 onward

snowjon

tylercollins wrote: »

Anyone know as to why no warnings have been issued for Northern Ireland? Are they expecting something else to happen maybe?

http://www.metoffice.gov.uk/weather/uk/ni/ni_forecast_warnings.html

Beats me! I'm sure they know what they are doing though - it looks like we will escape unscathed

maquiladora

snowjon wrote: »

Beats me! I'm sure they know what they are doing though - it looks like we will escape unscathed

Probably just waiting a bit longer to see how it pans out.

ninebeanrows

snowjon wrote: »

Beats me! I'm sure they know what they are doing though - it looks like we will escape unscathed

Mad really. Reckon they will issue flash warnings instead.

Maybe they think the Northern Irish are well used to widespread 60-70mph gusts?

irish1967

M4 Buoy gust on the climb
http://www.marine.ie/CMSWeb/mi/FusionCharts/DatabuoyChartFiles/Gust_M4.html

snowjon

Weathercheck wrote: »

Mad really. Reckon they will issue flash warnings instead.

Maybe they think the Northern Irish are well used to widespread 60-70mph gusts?

Seriously though, there must be a valid reason - the strongest winds must be moving further south than the models project?

irish1967

Cant see NI escaping enough of whats coming to stop at least an advisory.. strange alright

maquiladora

12Z UKMO has the centre of the low slighty further south than GFS, but pressure slightly higher. Six of one...

carlmwan

So? strong winds unlikely?

maquiladora

NMM model hi-res gust charts :

TheMilkyPirate

Me at 6pm tomorrow.

maquiladora

Malin, Shannon, Rockall, Fastnet 'increasing violent storm force 11 later'
Irish Sea 'increasing storm force 10 later'

maquiladora

Centre of the low going north between 4pm-5pm :

http://meteocentre.com/analyse/map.php?date=2010111017&lang=en&map=AtlN

M.T. Cranium

I think it's going to hit full force, no downgrades, and there should be a weather warning out for Northern Ireland. Would be quite confident of peak gusts at Aldergrove near 65 kts and possibly 70. Some more exposed places could see 80 in NI. As to the wind speeds in Donegal and Connacht, I just don't want to see any further signs of intensification because we're probably at the thresh-hold of significant damage now, unless the models are just totally off on this storm, it has all the signs of peaking at 10W and 1500h which would suggest wind gusts to at least 85 kts at Belmullet and possibly 90 kt at Malin Head. The higher these go, the more widespread the damaging 70-kt gusts elsewhere would become.

At this point I would be assuming the higher end of predicted forecast wind speeds and assessing what could come loose or fall over, get the cars into safe places where they won't get hit by debris or trees, and then if you get through unscathed, it's a good preparation for an even worse windstorm in the future. Almost all the big ones have a westerly component, this one should peak with winds at about 250 deg to 270 deg which is WSW to W.

I'm going back to look at more data but the one point I wanted to make about intensity is not to be too concerned about filling or rising central pressures after 15z, this would be normal for a storm of this intensity, it can't sustain the mid-940s over land but the storm is a process rather than a point event, and there is a lag time between minimum central pressure and strongest winds. The main point is that the track being slightly south of due east, the strongest winds in the 20W sector need to be around 56 N to come across the northern half of Ireland at about 54 N later on. It already appears that the models are verifying, the 12z maps are almost identical to their 24h model targets. When I return in a while, I am going to have an exact location for the centre and an intensity estimate based on any available data.

Su Campu

Here are the timings of tomorrow's strongest winds from today's 1700 TAFs, valid up to 1800 Thursday. Note winds will be strong from this evening onwards. I've also put in what I reckon will be the effect on air traffic, going on runway orientations and crosswind components. Just my opinion - DO NOT TAKE IT AS FACT, CHECK WITH YOUR AIRLINE!!!

Dublin
From 2pm - SW 27 gust 45 kts. Moderate rain showers.
Not enough to affect flights.

Shannon
From 10am - W 28 gust 45 kts. Moderate rain showers.
Not enough to affect flights.

Cork
From 2pm - W 26 gust 43 kts. Moderate rain showers.
Flight disruption possible due to crosswinds.

Connaught
From 9am - WSW 30 gust 48 kts. Moderate rain showers.
Not enough to affect flights.

Belfast Aldergrove
From 3pm - W 32 gust 45 kts.
Not enough to affect flights.

snowjon

M.T. Cranium wrote: »

I think it's going to hit full force, no downgrades, and there should be a weather warning out for Northern Ireland. Would be quite confident of peak gusts at Aldergrove near 65 kts and possibly 70. Some more exposed places could see 80 in NI. As to the wind speeds in Donegal and Connacht, I just don't want to see any further signs of intensification because we're probably at the thresh-hold of significant damage now, unless the models are just totally off on this storm, it has all the signs of peaking at 10W and 1500h which would suggest wind gusts to at least 85 kts at Belmullet and possibly 90 kt at Malin Head. The higher these go, the more widespread the damaging 70-kt gusts elsewhere would become.

At this point I would be assuming the higher end of predicted forecast wind speeds and assessing what could come loose or fall over, get the cars into safe places where they won't get hit by debris or trees, and then if you get through unscathed, it's a good preparation for an even worse windstorm in the future. Almost all the big ones have a westerly component, this one should peak with winds at about 250 deg to 270 deg which is WSW to W.

I'm going back to look at more data but the one point I wanted to make about intensity is not to be too concerned about filling or rising central pressures after 15z, this would be normal for a storm of this intensity, it can't sustain the mid-940s over land but the storm is a process rather than a point event, and there is a lag time between minimum central pressure and strongest winds. The main point is that the track being slightly south of due east, the strongest winds in the 20W sector need to be around 56 N to come across the northern half of Ireland at about 54 N later on. It already appears that the models are verifying, the 12z maps are almost identical to their 24h model targets. When I return in a while, I am going to have an exact location for the centre and an intensity estimate based on any available data.

Thanks for this MT - very interesting reading! Why do you think the UKMO are holding back any advisories or warnings for Northern Ireland? The forecast just goes as far as gale force winds:

Bright or sunny intervals and showers these possibly merging into a more prolonged spell of rain in the afternoon. Strong to gale force southwesterly winds picking up. Maximum temperature 10 °C.
http://www.metoffice.gov.uk/weather/uk/ni/ni_forecast_weather.html

maquiladora

M.T. Cranium wrote: »

When I return in a while, I am going to have an exact location for the centre and an intensity estimate based on any available data.

Thanks for the update MT. Have you seen this site before? It's updated hourly.

http://meteocentre.com/analyse/map.php?date=2010111017&lang=en&map=AtlN

irish1967

For a few days it looked like things were going to get risky with regard to wind speeds at around 2-3pm here on the northwest coast.

Am i reading it wrong or we looking at an earlier time now for things to get a risky with regard to debris and/or cross winds while driving. (Within 1 mile of the west facing Donegal coast)

darkman2

You are very exposed up in Donegal - in fact right along the Western seaboard. Id say there will be a few news stories by tomorrow night. Although relatively short lived this is a real event unlike the hyped up nonsense at the weekend. What that has done is put the media in an awkward posistion - so people now probrably don't have enough information of what may happen like power outages, downed trees etc. That and this is on a work day so even more likelyhood for disruption. Now when people could use the information in the media they are not getting it.


But hopefully we are not talking about severe disruption nationwide. The good news is that it should not last much beyond Early Friday morning as a wind event. And there should not be too much rain after the initial fronts pass through - but there will be some squally showers though.

Winger_PL

It would seem the centre has moved straight north in the last hour and did so by quite a distance, are we looking at a major downgrade here?

snaps

wind is getting up here now, starting to whistle down the chimney, also the rain has arrived

Su Campu

I wouldn't put too much stock into the meteocentre analyses for hours outside of 1200, 1500, 1800, 2100, etc, as there are limited marine observations at those hours. We'll probably see the centre come back south in the 1800 analysis, when there will be much more observations.

ninebeanrows

Winger_PL wrote: »

It would seem the centre has moved straight north in the last hour and did so by quite a distance, are we looking at a major downgrade here?

No, it is meaningless to look at 30 minute and hourly movements of a circulation like this in 3 hour loops. And are you looking at Satellite imagery or pressure plots.

The exact centre of the low would be very hard to pinpoint at this point as it is undergoing strong/rapid cyclogenesis.

M.T. Cranium

My estimate is about the same as the map link above, 18z position about 58N 23W and central pressure around 960 mbs. Since 12z the motion of the developing centre has been ENE but you do see some wobbles and I wouldn't read much into them, the main factor at play here is a deepening upper level low that models have consistently placed near northern Scotland at 18z Thursday, the surface low is a reflection of that and is not "in control" of its own path in this situation.

The storm has moved about 4-5 deg longitude since 12z from about 56N 28W at which time central pressure was estimated at 972 mbs.

For timing of strongest winds, would suggest that they will be rising rapidly any time after 1100h and peaking around 1500h in Connacht and Donegal, and this will likely be a fairly sustained 9-12 hour blow, lasting to almost midnight before letting up. Further east, add up to three hours on the timing depending on how far east.

Anyone with thoughts of observing, weather will be squally (this is part of the reason behind concern for widespread damaging gusts) and you might want to consider comfort and safety given that it won't just be a clear day with a strong wind, it could be pelting down hail at times, and briefly sunny at other times.

What are they expecting in Galway in terms of any storm surge? The wind direction is going to be ideal for piling water into Galway Bay.

DarkJager

Any ideas what impact this will have on Munster (specifically the Limerick/Cork area?) The forecasts seem to be suggesting it will be worst in Connaught and Ulster?

Min

Listening to John Eagleton there it sounded like it will not be anything exceptional. He didn't even mention any storm.

carlmwan

Min wrote: »

Listening to John Eagleton there it sounded like it will not be anything exceptional. He didn't even mention any storm.

ah why do they always downgrade at last min

Su Campu

Yes, he did seem to me not to dwell on tomorrow too much, though he did say severe gusts in the west and north, and very windy elsewhere. No mention of damage, plus with the tame enough TAFs I posted earlier, maybe they do see a downgrade. (The Belfast TAF is issued by the UK Met, so they're of the same thinking too.

Redsunset

carlmwan wrote: »

ah why do they always downgrade at last min

There's no downgrade,it's still evolving.And im out in it all day tomorrow,have a long drive home from Cahir Co Tipp at 6pm

Pangea

Met eireann seems to have pressed delete on the wind speeds for tomorrows forecast on the website , its still in the warning section though.

ninebeanrows

As some wise poster said earlier, the worst storms come with little media coverage, hype or detail.

They arrive unexpected to the masses.



This at the moment looks like a fair blow of a storm, around a 1 every winter event.

It has the potential to turn into a 1/5 winter event if developments were to speed up tonight.

But at the moment a 1/ every winter storm.