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

Louche Lad

NASlad wrote: »

How did the canaries/azores/madeira fare?

For the Azores, I think there wasn't much impact - it passed to the east. Some fallen trees, if Twitter's translation of tweets is correct. More stuff at:
http://m.dw.com/en/hurricane-ophelia-barrels-towards-ireland/a-40957188

Meteorite58

Looking Nasty to say the least

GFS Mean Wind Speeds




Gust

Meteorite58

If these charts are correct then it is looking very serious for a lot of the country.

APERGE 0Z


Mean





Gusts

Meteorite58

AROME Hi Res Model 0Z

Mean






Gusts

Meteorite58

WRF-NMM 0Z Hi Res just coming into view

Mean




Gust

Meteorite58

Mod Note : Reminder that there is a chat thread re preparations / disruptions, see below . Best keep this thread for more technical discussion.

Thanks for your cooperation.

http://www.boards.ie/vbulletin/showthread.php?t=2057797471

Louche Lad

Meteorite58 wrote: »

Mod Note : Reminder that there is a chat thread re preparations / disruptions, see below . Best keep this thread for more technical discussion.

Thanks for your cooperation.

http://www.boards.ie/vbulletin/showt...p?t=2057797471

I get "page not found"

Toxica

Meteorite58 wrote: »

Mod Note : Reminder that there is a chat thread re preparations / disruptions, see below . Best keep this thread for more technical discussion.

Thanks for your cooperation.

http://www.boards.ie/vbulletin/showt...p?t=2057797471

Page not found?

Toxica

Maybe this will work http://www.boards.ie/vbulletin/showthread.php?t=2057797471

Meteorite58

gordongekko

Louche Lad wrote: »

I get "page not found"

Toxica wrote: »

Page not found?

http://www.boards.ie/vbulletin/showthread.php?t=2057797471

DOCARCH

Just looking sat loop:

https://en.sat24.com/en/eu/infraPolair

Seems to be moving eastwards with very little northward movement at the moment.

Leads me to wonder could it miss Ireland altogether!

Two of the possible tracks on the chart above have it heading over France.

Meteorite58

munsterlegend

DOCARCH wrote: »

Just looking sat loop:

https://en.sat24.com/en/eu/infraPolair

Seems to be moving eastwards with very little northward movement at the moment.

Leads me to wonder could it miss Ireland altogether!

Two of the possible tracks on the chart above have it heading over France.

That would be something if it did somehow miss us.

vickers209

met have updated there forcast saying warning will be updated this morning see extra note at bottom of screen shot

DOCARCH

munsterlegend wrote: »

That would be something if it did somehow miss us.

Problem with hurricanes is they do their own thing!

Meteorite58

DOCARCH wrote: »

Just looking sat loop:

https://en.sat24.com/en/eu/infraPolair

Seems to be moving eastwards with very little northward movement at the moment.

Leads me to wonder could it miss Ireland altogether!

Two of the possible tracks on the chart above have it heading over France.

This is where the models say it is going to make its turn .

NHC

Ophelia is moving northeastward, or 055/24 kt ahead of a
mid-latitude trough moving over the northeastern Atlantic. The
hurricane should continue to accelerate northeastward tonight, then
turn north-northeastward with an additional increase in forward
speed by late Sunday and Sunday night. After the system occludes in
a couple of days, it should begin to slow down. The track guidance
is in good agreement, and the updated NHC track forecast is very
close to the previous advisory.

NHC

Hurricane Ophelia Discussion Number 24
NWS National Hurricane Center Miami FL AL172017
1100 PM AST Sat Oct 14 2017

Ophelia remains an impressive hurricane in infrared satellite
imagery. The hurricane continues to exhibit a large well-defined
eye within a ring of cold cloud tops. However, the overall cloud
pattern has started to elongate and there has been a slight erosion
of the area of cloud tops over the west and southwest portions of
the circulation as dry air and a frontal boundary encroaches on the
hurricane. Satellite intensity estimates from all agencies
continue to support an intensity of 100 kt. The aforementioned
changes in the cloud pattern and an expansion of the wind field as
noted by an earlier ASCAT overpass suggest that extratropical
transition has begun. The wind field is expect to significantly
expand over the next 12 to 24 hours, which is likely to lead to a
gradual decrease in the maximum winds. Ophelia is forecast to
complete extratropical transition within 24 hours, but it is
expected to remain a powerful post-tropical cyclone with
hurricane-force winds as it approaches Ireland on Monday. The
system is forecast to occlude and interact with land, which
should cause a faster rate of weakening in 48 to 72 hours, with
dissipation expected shortly thereafter.

DOCARCH

Was just putting it out there....

Still an outside chance that it may not come near us or head for the UK.

munsterlegend

DOCARCH wrote: »

Was just putting it out there....

Still an outside chance that it may not come near us or head for the UK.

It appears it's not doing anything too unexpected at the moment. Surely at this range the models couldn't be that far out but I understand it's a small chance.

DOCARCH

I suppose in the back of my head I am thinking of Irma....was supposed to head up the east coast of Florida and ended up the west coast of Florida at the last minute.

Ophelia is a Cat 3 'major' hurricane at the moment. I don't think it was forecast/expected to be that strong?

That, in my opinion, may effect the forecast track? The longer it remains a 'major' hurricane, the more the chance there is of it going wherever it pleases or resisting interaction with the jet stream.

As far as I am aware Ophelia was forecast to be weaker at this stage and the weaker hurricane was to be 'dragged' to Ireland by interaction with the jet stream.

Note: The above is not based on any science or forecast model! Just my own theory/hunch!

munsterlegend

DOCARCH wrote: »

I suppose in the back of my head I am thinking of Irma....was supposed to head up the east coast of Florida and ended up the west coast of Florida at the last minute.

Ophelia is a Cat 3 'major' hurricane at the moment. I don't think it was forecast expected to be that strong?

That, in my opinion, may effect the forecast track? The longer it remains a 'major' hurricane, the more the chance there is of it going wherever it pleases.

As far as I am aware Ophelia was forecast to be weaker at this stage and the weaker hurricane was to be 'dragged' to Ireland by interaction with the jet stream.

Note: The above is not based on any science or forecast model! Just my own theory/hunch!

Models are only predictive. As you said weather will do its own thing. It could certainly track further east alright.

irish1967

A screen shot I never thought I’d take on my phones weather App

DOCARCH

Maybe I'm just doing/making a Michael Fish of it....:p

Earlier on today, apparently, a woman posted on Boards and said she heard there was a hurricane on the way... well, if you're online, don't worry, there isn't!"

Meteorite58

ECMWF 0Z 850 hPa in Kts

Indicative of what gusts might be like

Meteorite58

GFS 0Z

Mean Wind speeds Kts





850 hPa Wind speeds Kts

M.T. Cranium

Those "models" heading for France are just momentum type models taking the recent motion and extending it forward, can safely be ignored.

The uncertainty at this point has narrowed to about 50 miles and places like Galway (city) towards Sligo town are in a zone of remaining uncertainty, will they be on the windy side of the track or the somewhat less windy west side; seems more certain that northwest Mayo will escape the strongest winds although not a guarantee yet.

This also means a degree of uncertainty as to how strong the winds might become along the east coast, but that uncertainty is basically the difference between level 2 and level 3 conditions at some point.

Most settled at this point seems to be the onset of very strong winds in most parts of Munster around late morning lasting into the afternoon, and in central regions by mid-afternoon lasting into early evening.

Extreme conditions could develop in some parts of Munster but I think we will have to play that quite short-range and just warn of that potential across the general area from Kerry to Waterford and some distance inland especially where topography allows strong southwest winds to penetrate well inland.

munsterlegend

I have a good weather app called weather pro. Just went to its worst warning red for my location in Cork when it was orange yesterday. Warning of considerable damage. Darwin was fairly bad here and this looks considerably worse again.

JCX BXC

Met Eireann update:

Tomorrow Monday, stormy conditions are expected to develop, in association with Ex-Hurricane Ophelia. Rain will be widespread, with the heaviest falls likely to occur in Atlantic coastal counties, where there is a risk of thunder. At present, it looks as though gusty east to southeast winds will strengthen to storm force in the southwest by early afternoon, with strong gales developing along southern, eastern and some western coasts during the afternoon and evening. The winds will veer southwesterly as the low pressure system tracks northwards over western parts of the country. Flooding is threatened due to potentially heavy falls of rain and very high seas. Top temperatures of 15 to 19 degrees.

Additional Note: At present, the strongest and most damaging winds are now forecasted to affect Munster and south Leinster, particularly the southwest, south and Irish Sea coasts with the heaviest rainfall accumulations in Connacht, west Ulster and west Munster. There are likely to be changes to the warnings which will be updated later this morning, pending the latest up to date guidance. This is an evolving situation and your patience is appreciated.

GeneHunt

DOCARCH wrote: »

I suppose in the back of my head I am thinking of Irma....was supposed to head up the east coast of Florida and ended up the west coast of Florida at the last minute.

Good point, I streamed some of the news from Florida before Imra hit (Irma was near Cuba at this stage) the news channels really played down the one track predicted by "The Europeans" of Irma tracking up the western side of Florida, all the other predicted tracks were up the east side of Florida. Sure what would the Europeans know!!!

Hope Ophelia mores off it's predicted track too, as this storms' predicted track (centre hitting Galway) is one of the worst scenarios. The South East is looking like it will get hammered.

Hope there's not too much idiots out on Monday trying to get "a good selfies".

venusdoom

Following this post for the last few days. Thank you so much for all the contributions. Prepared here in Donegal, but we may escape the worst. I don't know if this is related to what's to come, but we have a heavy purple sky right now. We are up early every morning and never seen such hue in the clouds.