Must admit I hadn't appreciated quite how quickly some of these depressions
move in the mid-Atlantic. So the NHC projection is showing Ophelia still
well south of the Azores at 1200Z Saturday and then off Ireland by the same
time Monday. Probably got too used in recent weeks to watching hurricanes
meandering (not really the right word to use for a hurricane) around at a
few knots for days on end.

Mildly interesting to get a name-check in the NHC commentary: 'Residents in
Ireland and the United Kingdom should monitor the progress of Ophelia for
the next several days.' Presumably that doesn't happen too often?

I also note the terminology in the NHC discussion: 'Ophelia is expected to
transition to a hurricane-force post-tropical cyclone by Monday when it
moves near Ireland and the UK.'

On 12/10/2017 21:00, JohnD wrote:
Mildly interesting to get a name-check in the NHC commentary: 'Residents
in Ireland and the United Kingdom should monitor the progress of Ophelia
for the next several days.' Presumably that doesn't happen too often?

I also note the terminology in the NHC discussion: 'Ophelia is expected
to transition to a hurricane-force post-tropical cyclone by Monday when
it moves near Ireland and the UK.'






That NHC discussion made me find out about "baroclinic low", this page
is compact and just about understandable to the techncal but otherwise
layman meterorologically speaking
http://www.met.rdg.ac.uk/~storms/concep/baro_inst/

I hope someone, more knowledgable than me, has told the people of the
south Eire coast (and as an outlier , in the Bristol Channel, as NHC has
upped their winds assesment and all numerical models must be outside
their comfort zones of the tweaks over the years), about the following,
if it has foundation. Would someone check my calculations on the -18
hour data and landfall of the centre of the storm.?
From Fig 5 correlation plot of the following
http://journals.ametsoc.org/doi/pdf/...2013EI000527.1

(BTW I like the use of newspaper archives to fill in the data holes)
Assuming enough hurricane character remaining, bathymetry and general
theory applies to this side of Atlanyic etc.
I make the surge , on making landfall, 2.6 metres.
I somehow doubt a port like Castletown could absorb such a surge if
occuring at their high tide of 14:30 GMT , on Monday

I've not seen any figure put to the storm surge at any landfall in the
media yet

I've just run the GFS 06Z run isotachs thru my English Channel surge widget.
The timing nd strength of the baroclinic wind enhancemet has seriously
worsened.
For the noon high tide at Southampton , of mid spring/neap tides regime,
I get a surge of 2m , which places it the highest for over 100 years,
perhaps 1824, 1804 and 1703 were higher.
I hope someone more knowledgable than me hasa handle on all this, the
consequences for the Bristol channel and English Channel , not just
Eire, in terms of storm surges.

Anyone else suspect a problem with Meteociel.fr ?
I suspect an error in the timing of the www public presentation pages
for GFS 0Z runs, something to do with converting some American time zone
of GFS generation, GMT and Central European times.
The 06,12,18hr outputs , stepped back the relevant 6 hours tend to agree
but the 0hr one does not , whenever I do these series of processings of
met to tide conversions.

I've emailed the 3 oceanographers, concerning Ophelia surges, I'm in
contact with other stuff, historic surge events. They soon put me
straight if I'm on the wrong track, suspiciously nothing in reply so
far. I suspect they are all outside of their comfort zones, one
comfortable with Australasian Typhoon surges, one polar sea/met
interactions, the other coastal matters.

I don't remember hearing the word phenominal in the shipping forecast
before, force 12 yes.
"Northwest Fitzroy, Sole
Cyclonic 5 to 7, increasing storm 10 to hurricane force 12. Moderate or
rough, becoming very high, occasionally phenomenal later. Rain or
showers. Moderate or good, becoming poor or very poor
Lundy, Fastnet, Irish Sea
South backing southeast for a time 5 to 7, increasing severe gale 9 to
violent storm 11 later, occasionally hurricane force 12 in Fastnet.
Moderate, becoming high or very high later, occasionally phenomenal in
Fastnet. Rain later. Moderate or good, becoming poor later"