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

aisling86

The Americans are watching this & they are absolutely fascinated.....I don't think there is the downgrade some are suggesting.....some interesting Twitter links above.

Akrasia

leahyl wrote: »

A serious downgrade? Really? Who’s saying this?

There are a lot of people who want to be the 'i told you so' guy, so they wander into a discussion, make a predictive statement pretending that they know it will happen, and only return to gloat if it turned out to be right.

It's like someone going all in in poker with a pair of 2s. If they lose they say they were bluffing, if they get a lucky draw and win with a full house, they claim foresight and skill

Meteorite58

Not a given, just to be used as a guide subject to change.

Mean speeds



Gusts

wowzer

Akrasia wrote: »

There are a lot of people who want to be the 'i told you so' guy, so they wander into a discussion, make a predictive statement pretending that they know it will happen, and only return to gloat if it turned out to be right.

It's like someone going all in in poker with a pair of 2s. If they lose they say they were bluffing, if they get a lucky draw and win with a full house, they claim foresight and skill

And the winner of post of the thread is....

Meteorite58

fraxinus1

leahyl wrote: »

A serious downgrade? Really? Who’s saying this?

Haastentoad and Gaooith laidir saying it's not going to be asent bad as what people think and one of then mentions max gust of 85mph which is strong but we get that somewhere in Ireland every year.

M.T. Cranium

There is no downgrade ... just too early to go up to level 3, but several models have potential for damaging wind gusts especially in Kerry, west Cork, west Limerick, Clare, and parts of Galway. One or two models would suggest potential for 160 km/hr gusts in exposed parts of Kerry and southwest Cork. The Hirlam model is suggesting that as the low approaches 50N it will continue to have hurricane force winds in the southern quadrant feeding around to the southeast quadrant.

Also the storm looks very impressive on satellite this morning.

Will be absent until about 16z (sleep time for me) and back for the 12z model run discussions.

Anyone reading the thread in west Munster or near Galway Bay should note that we are holding at level 2 for operational reasons but you are in a level 3 alert situation as of now according to most guidance. This may change for the better in later model runs.

leahyl

fraxinus1 wrote: »

Haastentoad and Gaooith laidir saying it's not going to be asent bad as what people think and one of then mentions max gust of 85mph which is strong but we get that somewhere in Ireland every year.

Yeah maybe off the coast of Donegal....in Cork, not so much....

Gaoth Laidir

fraxinus1 wrote: »

Haastentoad and Gaooith laidir saying it's not going to be asent bad as what people think and one of then mentions max gust of 85mph which is strong but we get that somewhere in Ireland every year.

I never said there was a downgrade. I was just pointing out differences in windspeed classification. When you see a NHC wind, take around 11% off it to get the standard Beaufort value.

Akrasia

I'm in Clare. Today is gonna be all about sorting out my house and making sure my relatives and friends are prepared

redsteveireland

Based on current guidance I know I'll be putting the trampoline away for sure. Shed is well sheltered, will see how it stands up to its first storm.

I will be in work in Galway city around the peak of the winds so I will be watching cautiously throughout the weekend.

Reckless Abandonment

So calm here in South Dublin. Looking at all the trees in lovely colour . Won't look so good on Tuesday going by the models

Gaoth Laidir

A nice satellite image of Ophelia now, showing water vapour below 700 hPa.

George Sunsnow

Darren Brett there on BBC News 24 just now saying gusts of 80 MILES per hour possible in eastern Northern Ireland

If that’s what pans out up there,there’s only one word for further south :eek:

Well I am very, very grateful for this thread. I'm spending the weekend tidying up the outside of my parents house. They live roughly 8 miles east of Mullaghmore,

I am more concerned about power outages than damage around the house as my dad is wheelchair/bed bound and all his food has to be pureed. He has an air mattress which will deflate after a few hours of no power. Because of the early warnings on this thread, I tried a normal mattress on the bed and it fits and I also acquired a special mattress topper for it.

I'm gonna buy a couple more flasks today and have soup and tea made. My sisters house is next door and she has a stove. Will light that first thing and use it for warming mashed potato and custard.

Penneys have gold/metal frame lights that are battery operated and these cheap one metre LED strips. The light off them is much better than a candle. If you're shopping today, I'd recommend buying some. Don't forget to buy AA + AAA batteries!

Once again, thanks all for the posts. I'm in the better to be safe than sorry camp.

Gaoth Laidir

Latest track guidance. The new NHC's new model the HMON has been pretty abysmal so far this year.

prunudo

George Sunsnow wrote: »

Darren Brett there on BBC News 24 just now saying gusts of 80 MILES per hour possible in eastern Northern Ireland

If that’s what pans out up there,there’s only one word for further south :eek:

Yeah, not much talk about the East coast but some of the models look like having very strong winds along Irish sea coastal counties.

George Sunsnow

jvan wrote: »

Yeah, not much talk about the East coast but some of the models look like having very strong winds along Irish sea coastal counties.

Aye there’s potential for a lot of flight disruption
I don’t see much activity at Dublin Airport with speeds like that even in gusts

leahyl

Thank god im coming home on Tuesday night - this will have passed by then

Meteorite58

Looks incredible seeing a hurricane so far North, well defined symmetrical eye.

guanciale

Hi folks and thank you for all of the info and advice. Informative and not hysterical.
I live in SW Kerry and have begun preparations. I would not be preparing at all only for this site. I think Met Eireann, the Govt and insurance companies could do a lot more to inform people. You have filled that void.

What is the advice for people with very large windows. US sites say do not tape up ut instead fit storm shutters. Is it the case here that we simply have to suck it up, hope for best and prep for worse. Or is there anything practical that can e done.
I have begun removing external potential missles.

Coax

Strawberry Milkshake wrote: »

Penneys have gold/metal frame lights that are battery operated and these cheap one metre LED strips. The light off them is much better than a candle. If you're shopping today, I'd recommend buying some. Don't forget to buy AA + AAA batteries!

Once again, thanks all for the posts. I'm in the better to be safe than sorry camp.

When buying torches, led lights etc, bear in mind than an AA battery has approx double the capacity of an AAA battery.

So if you have a choice of a light with a similar light output, go for one that uses AA batteries.

This means that for a given light you'll have longer operating from a set of AA batteries than from a set of AAA batteries.

Gaoth Laidir

Meteorite58 wrote: »

Looks incredible seeing a hurricane so far North, well defined symmetrical eye.

It's not that far north, it's still only at the latitude of Bermuda. Granted for the eastern Atlantic we see a lot less than that side.

Meteorite58

Kerry could get some wallop.

Gusts

pad199207

Meteorite58 wrote: »

Looks incredible seeing a hurricane so far North, well defined symmetrical eye.

Now that is one for the archives!

Gaoth Laidir

guanciale wrote: »

Hi folks and thank you for all of the info and advice. Informative and not hysterical.
I live in SW Kerry and have begun preparations. I would not be preparing at all only for this site. I think Met Eireann, the Govt and insurance companies could do a lot more to inform people. You have filled that void.

What is the advice for people with very large windows. US sites say do not tape up ut instead fit storm shutters. Is it the case here that we simply have to suck it up, hope for best and prep for worse. Or is there anything practical that can e done.
I have begun removing external potential missles.

The guys we see in the US boarding up windows and using storm shutters are doing so in preparation for proper hurricanes of Cat 2,3,4, etc. We may not get even Cat 1.

I think people are getting a bit carried away with this system. It will be windy, but the damage potential of what we may get is several times lower than say a Cat 3.

Clonmel1000

guanciale wrote: »

Hi folks and thank you for all of the info and advice. Informative and not hysterical.
I live in SW Kerry and have begun preparations. I would not be preparing at all only for this site. I think Met Eireann, the Govt and insurance companies could do a lot more to inform people. You have filled that void.

What is the advice for people with very large windows. US sites say do not tape up ut instead fit storm shutters. Is it the case here that we simply have to suck it up, hope for best and prep for worse. Or is there anything practical that can e done.
I have begun removing external potential missles.

I think M.E are playing a blinder on this so far and I’m happy for the government to be guided by the experts on this. This thread has been in the main excellent and enjoyable but you can see elements of hysteria from time to time.

star gazer

Hurricane Ophelia Discussion Number 21
NWS National Hurricane Center Miami FL AL172017
500 AM AST Sat Oct 14 2017

Ophelia's 20-nmi-diameter eye has continued to become more distinct
and cloud-free, with the eye temperature now reaching 15 deg C.
Satellite intensity estimates range from T4.5/77 kt from TAFB to
T5.0/90 kt from SAB and T5.5/102 kt from UW-CIMSS ADT. For now, the
initial intensity will remain at 85 kt, which is an average of the
available intensity estimates.

The initial motion estimate is 060/21 kt. Ophelia is embedded within
deep-layer southwesterly flow on the east side of a broad
mid-latitude trough. The global and regional models remain in
excellent agreement on the trough amplifying over the next 3-4 days,
which will cause the hurricane to accelerate toward the northeast at
forward speeds near 30 kt by 48 hours. The tight clustering of the
NHC model guidance, which shows very little cross-track or
along-track spread, increases the confidence in the official track.
As a result, no significant changes were made to the previous
advisory, and the new forecast track remains near the middle of the
guidance envelope, close to the HCCA and TVCX consensus models.

Ophelia is expected to remain in relatively low vertical wind shear
environment for the next 12 hours or so, which should help the
hurricane retain much of its current intensity during that time,
even though SSTs are only going to be 24-25C. However, upper-level
temperatures that are still about 2 deg C cooler than normal, which
will help to create sufficient instability to continue to drive the
development of inner-core convection. By 36 hours or so, the shear
is forecast to increase to 30-40 kt and the troposphere is expected
to become stable as sea-surface temperatures decrease to less than
20 deg C. However, even those SST values are about 2 deg C warmer
than normal for this time of the year. Those above-average ocean
temperatures are forecast to combine with strong baroclinic energy
associated with a potent, negatively tilted, upper-level trough,
causing Ophelia to transition into a powerful extratropical low
pressure system. By 48 hours, the post-tropical cyclone is forecast
to maintain sustained hurricane-force winds as it approaches
Ireland, with stronger winds expected over higher terrain.

Given that Ophelia is forecast to become extratropical, the wind
field should expand, resulting in impacts over portions of the
British Isles regardless of its exact location or strength. By 96
hours, Ophelia should have weakened due to the interaction with
land, causing the surface circulation to become ill-defined, and
dissipation is expected shortly thereafter.

Although the center of Ophelia is not forecast to reach Ireland or
the UK for another 48-60 hours, wind and rain effects will arrive
well in advance of the cyclone center. Individuals in those
locations should consult products from their local meteorological
service for more information on local impacts.

Tropical-storm-force winds are possible throughout the Azores
beginning tonight, primarily due to an approaching cold front.
However, any track deviation to the west could bring stronger winds
associated with Ophelia's circulation to those islands. Interests
in the Azores should refer to products issued by the Azores Weather
Forecast and Watch Center.

KEY MESSAGES:

1. Ophelia is expected to become a hurricane-force post-tropical
cyclone by Monday before it moves near Ireland and the United
Kingdom. Direct impacts from wind and heavy rain in portions of
these areas are likely, along with dangerous marine conditions. For
more details on the magnitude, timing, and location of impacts from
post-tropical Ophelia, residents in Ireland should refer to products
issued by Met Eireann, and residents in the United Kingdom should
refer to products issued by the Met Office.


FORECAST POSITIONS AND MAX WINDS

INIT 14/0900Z 33.9N 28.6W 85 KT 100 MPH
12H 14/1800Z 35.3N 25.4W 80 KT 90 MPH
24H 15/0600Z 38.3N 20.4W 80 KT 90 MPH
36H 15/1800Z 43.0N 16.0W 75 KT 85 MPH...POST-TROP/EXTRATROP
48H 16/0600Z 48.4N 12.5W 75 KT 85 MPH...POST-TROP/EXTRATROP
72H 17/0600Z 57.4N 6.3W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 18/0600Z 63.1N .5W 40 KT 45 MPH...POST-TROP/EXTRATROP
120H 19/0600Z...DISSIPATED

$$
Forecaster Stewart

NHC discussion 21

Discodog

Gaoth Laidir wrote: »

The guys we see in the US boarding up windows and using storm shutters are doing so in preparation for proper hurricanes of Cat 2,3,4, etc. We may not get even Cat 1.

I think people are getting a bit carried away with this system. It will be windy, but the damage potential of what we may get is several times lower than say a Cat 3.

Plus our buildings are low & block construction. The real damage will be from trees & blowing debris. People should try to park their car in a sheltered spot & make sure that there is nothing to blow around like wheelie bins.

Oneiric 3

Peak mean & gust speeds (knots) from the latest UK Met run for major coastal towns. Note that this is still low res territory so should be treated as nothing more than conservative guidance at this stage:

Mean/Gust
Belfast: 21/46
Derry: 23/46
Sligo: 26/47
Galway: 29/51
Limerick: 26/51
Cork: 30/57
Waterford: 31/56
Dublin: 25/46

Shall update this list on next run.