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Extratropical Storm Ophelia - Technical Analysis Only - MOD NOTE post #1

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  • Registered Users Posts: 3,391 ✭✭✭amandstu


    Does anyone know what innovative techniques met eireann might have used for this uncharted territory?

    They couldn't rely on historical data. Did they just give it everything they had and cross fingers?



    Is there something similar coming perhaps next Fri/Sat? (oops I see the thread now)


  • Registered Users Posts: 11,205 ✭✭✭✭hmmm


    Would someone be able to explain why many people, particularly I think in the East, were reporting that the winds were stronger in the very late evening than during the day? At that stage the center of the storm appeared to be passing beyond Donegal.


  • Registered Users Posts: 8,219 ✭✭✭Gaoth Laidir


    hmmm wrote: »
    Would someone be able to explain why many people, particularly I think in the East, were reporting that the winds were stronger in the very late evening than during the day? At that stage the center of the storm appeared to be passing beyond Donegal.

    The mean speeds at Dublin Airport were actually stronger last night than they were during the afternoon, and with the SW direction it caused a lot of problems with aircraft around 11 pm. There was a tight gradient on the back end of the system that caused this wind.

    00_UKMet_Boden+00.gif


  • Registered Users Posts: 10,515 ✭✭✭✭MJohnston


    hmmm wrote: »
    Would someone be able to explain why many people, particularly I think in the East, were reporting that the winds were stronger in the very late evening than during the day? At that stage the center of the storm appeared to be passing beyond Donegal.

    Almost certainly the wind direction shift meant that the Wicklow/Dublin mountains were no longer providing a 'shield' against the wind.


  • Registered Users Posts: 23,822 ✭✭✭✭Larbre34


    amandstu wrote: »
    Does anyone know what innovative techniques met eireann might have used for this uncharted territory?

    They couldn't rely on historical data. Did they just give it everything they had and cross fingers?



    Is there something similar coming perhaps next Fri/Sat? (oops I see the thread now)

    Yeah they rang Miami. The US National Hurricane Centre gave them extensive support, by all accounts, around modelling and evolutions. I think the outcomes proved that co-operation was successful.

    Yesterday's exercise will add to the expertise of Met É considerably.

    Storm Brian is much more bread and butter stuff for them, but overall UK is more at risk.


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  • Registered Users Posts: 666 ✭✭✭Full Marx


    I've greatly enjoyed this thread, would anyone recommend an accessible book on meteorology for the uninitiated? I'd like to be more up to speed for the next storm thread haha


  • Registered Users Posts: 6,235 ✭✭✭Oneiric 3


    What were the rainfall metrics yesterday? I expected heavy rain in Galway but it seemed quite patchy and there is no flooding today.
    We had some torrential showers early to mid morning in this part of the county, followed by driving moderate rain during the height of the gale. Nothing exceptional accumulation wise though (around 10mm)

    New Moon



  • Registered Users Posts: 15,322 ✭✭✭✭Supercell


    I think the Wicklow mountains provided considerable protection to Dublin, or at least southern Dublin during the height of this. Reviewing my weather records for the last few five years or so, this storm would rank around third place on an annual basis on average windspeed or maximum gust, so far from anything exceptional here with little of any damage around this local area that i can see.
    Not writing off the seriousness of it, just an observation that Dublin got off very lightly all things considered. I do worry that should there be another storm of a similar nature with stronger easterly or westerly winds that Dubliners may be in for an unpleasant surprise and may well be totally unprepared for it.

    Have a weather station?, why not join the Ireland Weather Network - http://irelandweather.eu/



  • Registered Users Posts: 6,235 ✭✭✭Oneiric 3


    Regarding the 'Appege' model and its high accuracy in predicting the path of the low and the wind field over Ireland as others have mentioned, I read a couple of years ago that this very same model was the first to pick up on the path of the October 1987 storm in the UK back in the day. I also distinctly remember that this model was the first to show the potential for high winds over the west and north of Ireland during last Feb or March (I can't remember exact month) when all the other major models had the brunt of the storm hitting the south and east. I am sure too, that it has been very way off during other events but at the end of the day (GAA commentary mode :p ) it is a model that should not be dissed when it is showing wind potential.

    New Moon



  • Moderators, Home & Garden Moderators, Science, Health & Environment Moderators Posts: 17,721 Mod ✭✭✭✭DOCARCH


    Supercell wrote: »
    I think the Wicklow mountains provided considerable protection to Dublin, or at least southern Dublin during the height of this. Reviewing my weather records for the last few five years or so, this storm would rank around third place on an annual basis on average windspeed or maximum gust, so far from anything exceptional here with little of any damage around this local area that i can see.

    On the other hand....I am not a million miles from you.

    Yesterday, at 1430 (in Dublin 16), I recorded the highest wind speed I have ever recorded since getting my weather station in October 2011.

    So, for some, the mountains may have provided shelter, but not all places!

    When the wind passes over the mountains it causes the wind to oscillate vertically so you get pockets of strong winds.

    Yesterday somebody put up a link to a Dublin Fire Brigade (DFB) map of incidents DFB attended too yesterday and the majority were mid-south side Dublin....may be explained by the above?


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  • Registered Users Posts: 15,322 ✭✭✭✭Supercell


    DOCARCH wrote: »
    On the other hand....I am not a million miles from you.

    Yesterday, at 1430 (in Dublin 16), I recorded the highest wind speed I have ever recorded since getting my weather station in October 2011.

    So, for some, the mountains may have provided shelter, but not all places!

    When the wind passes over the mountains it causes the wind to oscillate vertically so you get pockets of strong winds.

    Yesterday somebody put up a link to a Dublin Fire Brigade (DFB) map of incidents DFB attended too yesterday and the majority were mid-south side Dublin....may be explained by the above?

    Thats quite interesting Doc, I wonder if proximity to Dalkey/Killiney hills here also provides some additional shelter?
    I noticed on the electrical outages map yesterday that Terenure and Dundrum had several power outages which concurs with your own experiences.

    Have a weather station?, why not join the Ireland Weather Network - http://irelandweather.eu/



  • Moderators, Motoring & Transport Moderators Posts: 6,521 Mod ✭✭✭✭Irish Steve


    Supercell wrote: »
    I think the Wicklow mountains provided considerable protection to Dublin, or at least southern Dublin during the height of this. Reviewing my weather records for the last few five years or so, this storm would rank around third place on an annual basis on average windspeed or maximum gust, so far from anything exceptional here with little of any damage around this local area that i can see.
    Not writing off the seriousness of it, just an observation that Dublin got off very lightly all things considered. I do worry that should there be another storm of a similar nature with stronger easterly or westerly winds that Dubliners may be in for an unpleasant surprise and may well be totally unprepared for it.

    The Wicklow mountains were providing shadow out as far as Ashbourne if our experience here is anything to go by, the gusts in the evening when the winds veered to more Westerly was that they were more intense and violent than they had been during the afternoon. It's very noticeable that there are very few power outages in the area directly North of the mountains, and I'm pretty convinced that the shadow of the mountains has a lot to do with that.

    I was online and looking at the various sites on Saturday evening when the nationwide Red alert was declared, and at that time, the track being predicted was slightly different, and the Dublin area was being shown as getting extreme South Easterly winds earlier in the day, with more emphasis on the East component, which would have meant little protection would have been given by the mountains. In the event, there was a lot less East component in the wind, which helped to significantly mitigate the strength felt in the Dublin area, and for sure reduced the damage that occurred. As to the exact why, I'll leave that analysis to the weather experts, I am guessing it was down to the track that the storm took, and the way that the adjacent higher pressure areas influenced things. The track it took also meant that East Clare didn't get hammered to the degree that was being forecast, the proximity of the eye to the coast meant that the winds in that area were less, again, a good thing, my son is on top of a hill with precious little between him and Newfoundland, so they were very happy that the original forecast did not quite happen, what did go through was more than enough for him, he'd been warned what was coming, so anything that could move had already been moved.

    For me, even if some places didn't get the severity that was possible, it was a good call, and I am very sure that making it wasn't easy, but I am sure that it did save lives. As for some of the people complaining, if the loss of significantly less than half a percentage point of their annual turnover is going to cause them such severe problems, there are questions to be asked about how that business is operating and being financed.

    Shore, if it was easy, everybody would be doin it.😁



  • Moderators, Home & Garden Moderators, Science, Health & Environment Moderators Posts: 17,721 Mod ✭✭✭✭DOCARCH


    Supercell wrote: »
    Thats quite interesting Doc, I wonder if proximity to Dalkey/Killiney hills here also provides some additional shelter?
    I noticed on the electrical outages map yesterday that Terenure and Dundrum had several power outages which concurs with your own experiences.

    Wind at the time was (roughly) SE. For me, wind from that general direction comes over Three Rock and can gain quite a bit of speed/can be quite gusty....as it was yesterday. Some really big gusts between about 2 and 3pm.


  • Registered Users Posts: 13,510 ✭✭✭✭joujoujou
    Unregistered Users


    Finally got an internet connection up again.

    Some of my station's data from yesterday:

    - highest wind gust - 88.2 km/h @ 16:22
    - highest wind speed - 75.7 km/h @ 16:18
    - lowest pressure (130 m ASL) - 949.9 hPa @ 15:46.

    I wonder what (and where) was yesterday's lowest pressure recorded.

    Anyone knows?


  • Registered Users Posts: 8,219 ✭✭✭Gaoth Laidir


    joujoujou wrote: »
    Finally got an internet connection up again.

    Some of my station's data from yesterday:

    - highest wind gust - 88.2 km/h @ 16:22
    - highest wind speed - 75.7 km/h @ 16:18
    - lowest pressure (130 m ASL) - 949.9 hPa @ 15:46.

    I wonder what (and where) was yesterday's lowest pressure recorded.

    Anyone knows?

    Valentia, 962 3 hPa at 11Z. That was an hourly report so it may have been less in between hours.


  • Registered Users Posts: 18,996 ✭✭✭✭gozunda


    Lost power (and internet connection) at approx 13.30 yesterday at height of storm - power back approx 55 mins ago.

    Before losing power recorded gust of 76.4 km/h although reckon the wind odometer was partially sheltered and did not pick up full strength of the wind

    Pressure dropped to a low of 963 hpa at that point and was still dropping

    Wind & gusts dropped in strength around 16.00 but then increased again in strenght between 19.00 - 21.00

    Lots of trees down on local roads / power and phone lines damaged.

    East Limerick Cork Border


  • Registered Users Posts: 373 ✭✭waterways


    The gusts weren't that strong as expected, luckily I have to add, but they caused a lot of damage. Why? Any explanations available? Was it the wind direction or the turbulence?


  • Registered Users Posts: 9,922 ✭✭✭spookwoman


    waterways wrote: »
    The gusts weren't that strong as expected, luckily I have to add, but they caused a lot of damage. Why? Any explanations available? Was it the wind direction or the turbulence?
    Frequency and how long they lasted, then add weakpoints and surface fatigue wear and something has got to give


  • Banned (with Prison Access) Posts: 3,288 ✭✭✭mickmackey1


    Valentia, 962 3 hPa at 11Z. That was an hourly report so it may have been less in between hours.
    Saw a Met Eireann tweet referring to 959 at Valentia.


  • Registered Users Posts: 373 ✭✭waterways


    max gusts kmh yesterday


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  • Registered Users Posts: 6,235 ✭✭✭Oneiric 3


    For what it is worth, my station recorded a pressure range of a whopping 38.5 hPa in just under a 15 hour period yesterday. Max reading for yesterday was 1011.4 hPa at 1.04am, while min reading, recorded at 3.58pm, was 972.9 hPa.

    New Moon



  • Moderators, Science, Health & Environment Moderators Posts: 11,828 Mod ✭✭✭✭Meteorite58


    Nice one Met Eireann

    XR1z3WQ.jpg?1


  • Moderators, Society & Culture Moderators Posts: 6,769 Mod ✭✭✭✭nuac


    Congrats to MET Eireann on their assessments and reports. Well done


  • Registered Users Posts: 6,544 ✭✭✭Samaris


    Full Marx wrote: »
    I've greatly enjoyed this thread, would anyone recommend an accessible book on meteorology for the uninitiated? I'd like to be more up to speed for the next storm thread haha

    In my also pretty uninitiated way, I'd recommend Essentials of Meteorology by C Ahrens. It's a standard first year college textbook, so it's pretty accessible and explains all the definitions, etc.


  • Moderators, Science, Health & Environment Moderators Posts: 11,828 Mod ✭✭✭✭Meteorite58


    Here near Tralee out by the coast missed the strongest winds and rains. Got a top gust of 85.3 km/h E and was gusting well into the 70's between 10.30 and 12.30 during which I got the strongest gust. Highest 10 min avg was 46.7 km/h at 12.00 ( Anemometer at 7.3m ) .

    Winds from 00.00 to 3.00 NE
    3.00 to 06.00 ENE
    6.00 to 7.30 ESE
    7.30 to 13.30 SE
    13.30 to 18.30 mix of WSW and SW
    18.30 to 0.00 W

    Rain : 8.2mm
    High Temp 16.6C at 8.00 / low 9.8 at 00.00



    Lowest Bar reading 965.8 hPa at 12.30 / 13.00


    No damage done locally to my knowledge apart from branches. Power flickered on and off during the strongest winds .

    Thanks to everyone for their contribution I learnt a lot.





    Pic taken near the eye center at 13.30 approx looking approx SW

    3VChXp4.jpg?1

    NASSA Sat Pic close to that time I reckon.


    PjE637L.jpg?1


    Ijh15Dd.jpg?1


  • Registered Users Posts: 722 ✭✭✭Carol25


    Well done to everyone here and at Met Éireann. Great job done in keeping everyone up to date on their storm predictions, the latest model readings and then it's track and behaviour as it passed over us. Great job all around ðŸ‘ðŸ»ðŸ™‚


  • Registered Users Posts: 8,219 ✭✭✭Gaoth Laidir


    Provisional Ophelia gusts.

    37054594394_06cd4f5391.jpg


  • Registered Users Posts: 18,112 ✭✭✭✭JCX BXC


    In terms of red warning creiteria (guidelines), it seems just the very south of Ireland reached that status. However it was most certainly the right decision to declare red for all counties. While the guidelines are there, the experts (Met Eireann) should definitely continue to issue them where they feel they are warranted.

    Darwin in 2014 was not declared red until far too late and stupid dangerous things occured like primary schools sending children home in the height of the storm. (Seriously!) Had this not been declared red, I'd imagine the death toll would be much higher than 3.


  • Registered Users Posts: 1,785 ✭✭✭piuswal


    Weather Data for Yesterday 16-Oct-2017
    Station Rain Max Min Sun Gust Wind Soil Global Gmin
    Athenry 4.7 16.7 9.6 50 17.0 12.1 277 8.7
    Ballyhaise 8.4 16.4 9.6 50 13.8 12.1 241 9.4
    Belmullet 22.4 14.0 8.8 0.1 47 18.1 11.9 151 8.3
    Casement 1.6 17.8 10.2 2.4 63 23.7 13.3 8.9
    Claremorris 12.3 15.9 8.9 44 17.9 12.0 235 8.0
    Cork Airport 7.6 16.4 8.7 0.2 70 25.6 12.7 7.6
    Dublin Airport 0.7 17.2 11.4 1.0 56 21.7 13.3 470 9.6
    Finner Camp 14.5 16.0 8.9 54 17.6 n/a 219 8.6
    Dunsany 2.1 17.5 11.2 57 18.7 13.2 446 10.5
    Gurteen 6.3 17.5 9.9 0.4 55 19.5 13.1 269 8.7
    Johnstown Castle 1.4 17.2 11.1 1.7 62 21.5 13.7 371 9.7
    Knock Airport 14.7 14.0 7.9 0.4 50 19.9 11.5 7.9
    Mace Head 22.1 14.9 9.6 51 27.4 n/a 257 9.2
    Malin Head 9.4 16.5 9.1 0.9 57 28.3 11.8 261 8.3
    Markree Castle 11.7 16.9 9.1 n/a n/a 12.1 309 8.8
    Moore Park 8.1 17.6 10.6 62 16.9 13.7 464 9.5
    Mt Dillon 7.0 16.3 9.5 50 16.4 12.9 237 9.2
    Mullingar 8.0 16.5 10.1 49 15.2 13.2 314 8.8
    Newport Furnace 25.6 14.9 9.5 43 16.0 11.7 215 8.6
    Oak Park 3.4 17.9 10.7 60 20.1 13.3 323 8.4
    Phoenix Park 0.9 18.1 11.4 n/a n/a 14.3 646 9.0
    Roches Point 8.8 17.0 10.4 84 32.4 12.9 234 8.5
    Shannon Airport 3.9 18.0 10.4 0.0 66 24.4 13.1 8.9
    Sherkin Island
    Valentia 19.0 19.4 10.4 0.8 53 22.2 13.8 427 8.8


    http://www.met.ie/latest/yesterday.asp


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  • Registered Users Posts: 10,515 ✭✭✭✭MJohnston


    piuswal wrote: »
    Weather Data for Yesterday 16-Oct-2017
    Station Rain Max Min Sun Gust Wind Soil Global Gmin
    Athenry 4.7 16.7 9.6 50 17.0 12.1 277 8.7
    Ballyhaise 8.4 16.4 9.6 50 13.8 12.1 241 9.4
    Belmullet 22.4 14.0 8.8 0.1 47 18.1 11.9 151 8.3
    Casement 1.6 17.8 10.2 2.4 63 23.7 13.3 8.9
    Claremorris 12.3 15.9 8.9 44 17.9 12.0 235 8.0
    Cork Airport 7.6 16.4 8.7 0.2 70 25.6 12.7 7.6
    Dublin Airport 0.7 17.2 11.4 1.0 56 21.7 13.3 470 9.6
    Finner Camp 14.5 16.0 8.9 54 17.6 n/a 219 8.6
    Dunsany 2.1 17.5 11.2 57 18.7 13.2 446 10.5
    Gurteen 6.3 17.5 9.9 0.4 55 19.5 13.1 269 8.7
    Johnstown Castle 1.4 17.2 11.1 1.7 62 21.5 13.7 371 9.7
    Knock Airport 14.7 14.0 7.9 0.4 50 19.9 11.5 7.9
    Mace Head 22.1 14.9 9.6 51 27.4 n/a 257 9.2
    Malin Head 9.4 16.5 9.1 0.9 57 28.3 11.8 261 8.3
    Markree Castle 11.7 16.9 9.1 n/a n/a 12.1 309 8.8
    Moore Park 8.1 17.6 10.6 62 16.9 13.7 464 9.5
    Mt Dillon 7.0 16.3 9.5 50 16.4 12.9 237 9.2
    Mullingar 8.0 16.5 10.1 49 15.2 13.2 314 8.8
    Newport Furnace 25.6 14.9 9.5 43 16.0 11.7 215 8.6
    Oak Park 3.4 17.9 10.7 60 20.1 13.3 323 8.4
    Phoenix Park 0.9 18.1 11.4 n/a n/a 14.3 646 9.0
    Roches Point 8.8 17.0 10.4 84 32.4 12.9 234 8.5
    Shannon Airport 3.9 18.0 10.4 0.0 66 24.4 13.1 8.9
    Sherkin Island
    Valentia 19.0 19.4 10.4 0.8 53 22.2 13.8 427 8.8


    http://www.met.ie/latest/yesterday.asp

    "Wind is the mean wind speed in knots" - not a particularly useful statistic that one, there was a lot of the day that was extremely calm before the storm arrived, and it calmed down quite a bit in certain areas after it passed.


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