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

LastLagoon

Most focus seems to be on the wind and how we haven’t seen anything like this before
How about the rain? How will it compare to some of the downpours that have cause havoc in previous years
And how bad would storm surge be? Just south facing coasts?

rossie1977

The nullschool site also shows strengthening winds to the west of the eyewall of 130 kph

star gazer

Ophelia's track stays a little East like last NHC advisory
Remember there's a rainfall warning also, particularly in the West.

Wunderground have another addition

The One Doctor

Lenny5 wrote: »

Could there be any unusual cloud formations, lightning, hail, or other weird events with this storm tmrow? Just wondering as its such an unusual event.

Estofex says there's a small tornado risk.

M.T. Cranium

batman2000 wrote: »

I'd say because Met Eireann said tonight it's expected at 6am.

I was referring to maps with the time stamps shown on them, those need to be converted. The onset might be 0600h but the strongest part of the windstorm will be around 1100h in the south coast lasting 2-4 hours. This is the confusion I wanted to avoid.

Sparks43

M.T. Cranium wrote: »

I was referring to maps with the time stamps shown on them, those need to be converted. The onset might be 0600h but the strongest part of the windstorm will be around 1100h in the south coast lasting 2-4 hours. This is the confusion I wanted to avoid.

Always enjoy readings your analysis and forecasts

A question though.

Some very strong winds seem to be hitting just off the coast of Dublin. Do storms accelerate over sea and slow down over land.

Also how bad can bad get for north east Dublin. We are up high and not too far off the coast.

Thanks in advance

gitzy16v

Is that nullschool earth site up to date?...I read somewhere else that its 3hrs behind.

Meteorite58

Mod Note

This thread is for technical analysis only please - there’s a general discussion thread available for everything else

Thanks

drunkmonkey

gitzy16v wrote: »

Is that nuschool earth site up to date?...I read somewhere else that its 3hrs behind.

It's well behind sat24, that has it gone past france now.
https://en.sat24.com/en

The high horse brigade

gitzy16v wrote: »

Is that nullschool earth site up to date?...I read somewhere else that its 3hrs behind.

Click where it says earth, it should tell you the time it's based on

Meteorite58

ICON 18Z ( looks to giver higher wind speeds then the other models, we will see when the others come out later )

Might get the center close to here near Tralee mid afternoon.

Mean




Gusts

mel.b

Is it just me or does it look like from the sat24 image that it is (has?) shifting slightly more west?

Bonzo Delaney

mel.b wrote: »

Is it just me or does it look like from the sat24 image that it is (has?) shifting slightly more west?

Bet me to it

Super-Rush

Definitely a shift to the west.

civdef

Just a query regarding yr.no, what models would they be using for forecasts of Ireland- generally find them good, but their wind speeds for tomorrow seem to be out of kilter?

mickger844posts

mel.b wrote: »

Is it just me or does it look like from the sat24 image that it is (has?) shifting slightly more west?

Certainly looks that way but the Jet Stream will probably push her back onto the forecast track. She is moving fast though. Think it will arrive a few hours earlier than forecasts.

www.waterfordweather.com

FrancieBrady

mel.b wrote: »

Is it just me or does it look like from the sat24 image that it is (has?) shifting slightly more west?

RTE say it won't make a lot of difference if it shifts a bit

Meteorite58

The 18Z GFS just rolling out, looks wicked.

Mean



Gusts

Donegal Storm

Latest gfs out, track seems to be a touch further west with around 75kt gusts briefly on the south coast and in general about 50-60kts possible anywhere, again I'd say nothing exceptional but still strong enough to down trees across large parts of the country.

18Z GFS seems to push it a bit west again.




Wind gusts not as strong as what other models are showing?

lucernarian

[Deleted User] wrote: »

Wind gusts not as strong as what other models are showing?

Indeed, not a particularly bad storm for the time of year if that came off? Would be lighter than the current red alert suggests, and let's hope so. But GFS hasn't been great this season and I'm not inclined to trust in its downgrade, especially when nowcasting with satellite imagery shows greater gust potential than that.

M.T. Cranium

Centre approx 46.5N 11.8W moving almost due north now, lightning reported on the developing front extending to the southeast of the centre. Looks fully hybrid or extratropical now, as you prefer.

GFS 18z has centre near Valentia at 1300h and over Connemara 1600h. Slight shift back to west compared to earlier run and NHC track.

lucernarian

M.T. Cranium wrote: »

Centre approx 46.5N 11.8W moving almost due north now, lightning reported on the developing front extending to the southeast of the centre. Looks fully hybrid or extratropical now, as you prefer.

GFS 18z has centre near Valentia at 1300h and over Connemara 1600h. Slight shift back to west compared to earlier run and NHC track.

And also weaker forecast max gusts too it seems?

bloopy

M.T. Cranium wrote: »

Centre approx 46.5N 11.8W moving almost due north now, lightning reported on the developing front extending to the southeast of the centre. Looks fully hybrid or extratropical now, as you prefer.

GFS 18z has centre near Valentia at 1300h and over Connemara 1600h. Slight shift back to west compared to earlier run and NHC track.

Does this change the forecast much or is it essentially the same as what we've been told all day?

Gaoth Laidir

Latest wind analysis, showing max 1-minute winds down to 66 knots and a greatly shrinking 65-knot area.



18Z early track forecast still as you were. The black line is the official NHC track.

Meteorite58

Almost there, gulp!

gozunda

gitzy16v wrote: »

Is that nullschool earth site up to date?...I read somewhere else that its 3hrs behind.

From the link shown just - 1 hour. The reports of the eye disintegrating were prior to that ...

M.T. Cranium

Maybe more of an adjustment to max wind gusts than a general decrease from that 18z GFS, but in no case would I infer any major downgrade ... on that track meanwhile Galway city and all of Clare are exposed to stronger winds than on the slightly inland track of NHC.

Much of the outcome depends on strength of occluded front that is now evident in formative stages, this will accelerate faster than the low centre.

Now thinking onset of strongest winds about 10:00 south coast, persisting 3-4 hours, and about 14:00 Clare-Galway lasting 2-3 hours. Keep in mind meteociel times are CET and one hour ahead of IST. (1400 on their map = 1300 IST = 12z).

detones

Honestly one of the most inappropriate comments I've ever seen on boards.

Mod Note: Post removed. Use report button .

Meteorite58

Size of the predicted wind field close to now.