Hurricane Ophelia

[cheese]

8 hours ago, Daniel* said:

You’re being childish you’re doing the right thing if you want your account to cease to exist. Get a grip the UK will never be able to get a hurricane which makes landfall yes never, we can certainly have hurricane force winds, but not a hurricane with an eyewall and tropical convection bands - our northerly latitude simply does not allow it. 

I wouldn't say it's impossible - if Hurricane Debbie maintained tropical characteristics just off the coast of Ireland in 1961 then surely it's possible for such a system to landfall in the UK? Tropical Storm Grace also maintained tropical characteristics as north as Brest in France before transitioning.

In fact, the most remarkable example would be Hurricane Fath in 1966 which was a fully-fledged catergory 1 hurricane between Scotland and the Faroe Islands. That's north of 60 degrees.

A lot of things are impossible, but I'm not sure a hurricane or a tropical storm landfalling in the UK or Ireland is impossible.

 

Edited October 14, 2017 by cheese

[Snowman.]

Dvorak now at 5.5 / 102kts

Which makes her a Cat 3.

http://tropic.ssec.wisc.edu/real-time/adt/odt17L.html

[cowdog]

Ok I wasn't exactly that worried about this storm as Ireland gets this level of wind occasionally - thats until now.

Dvorak has increased over night and is now at 5.5 - thats deep in Category 3 territory. This storm isn't behaving as predicted, as was expected to start weakening now - not getting to the strongest its been!

[JBMWeatherForever]

NHC still forecast Ophelia to start to weaken from about 24 hours time when a cold front reaches its circulation. They forecast it to become extratropical  but still with hurricane force winds in about 48 hours time. This is of course not certain. 

Edited October 14, 2017 by JBMWeatherForever

[SnowBear]

43 minutes ago, cheese said:

I wouldn't say it's impossible - if Hurricane Debbie maintained tropical characteristics just off the coast of Ireland in 1961 then surely it's possible for such a system to landfall in the UK? Tropical Storm Grace also maintained tropical characteristics as north as Brest in France before transitioning.

In fact, the most remarkable example would be Hurricane Fath in 1966 which was a fully-fledged catergory 1 hurricane between Scotland and the Faroe Islands. That's north of 60 degrees.

A lot of things are impossible, but I'm not sure a hurricane or a tropical storm landfalling in the UK or Ireland is impossible.

 

There is a lot of uncertainty with H.Debbie '61, no one really knows when she transitioned. H.Faith '66 was an very fast moving hurricane, forward speed of 50mph+, weakening/transitioning all the while, the energy source by the time it reached the Faroes would have long been cut off as sea surface temperatures would have been too low. That forward momentum though did mean it could barrel its way further north before fully transitioning into an extra-tropical.

I would say Spain, Portugal and maybe an outside chance France could get tropical cyclones in the proper form. The most recent being the hybrid H.Vince '05. This storm did develop in the NE Atlantic over slightly cooler waters than usually required for tropical initiation (24°c) , in my view it was more akin to a rare Mediterranean tropical system which form differently to hurricanes and do not require sst of 26°c.

 

[MattStoke]

Why do we see more fully tropical systems on the other side of the Atlantic at the same latitude?

[SnowBear]

4 minutes ago, MattStoke said:

Why do we see more fully tropical systems on the other side of the Atlantic at the same latitude?

This link explains fairly well and more..

http://www.hurricanescience.org/science/science/hurricanemovement/

[radiohead]

 

000
WTNT42 KNHC 140858
TCDAT2

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

[Man With Beard]

55 minutes ago, SN0WM4N said:

Dvorak now at 5.5 / 102kts

Which makes her a Cat 3.

http://tropic.ssec.wisc.edu/real-time/adt/odt17L.html

Well that is a turn-up (I'm not experienced in these products so I'm presuming it's reliable). Does that mean its forecast intensity as an ex-tropical storm would need upgrading too?

[Man With Beard]

Latest GFS 06Z just a touch further east and that brings the Irish Sea into play more. 70-80mph clipping Cornwall/Pembrokeshire/Anglesea but just a matter of miles away from the 90mph zone. Touch and go in these areas. No change in the prognosis for Ireland.

[NO LONGER POSTING]

She really is not behaving, warmer than average ssts are keeping her grumpy for longer 

[Paul]

Not the typical low you'd expect to be hanging around to our southwest!

[Mokidugway]

2 minutes ago, Paul said:

Not the typical low you'd expect to be hanging around to our southwest!

Like been photobombed by a hurricane 

[Polar Maritime]

This mornings Net-Wx MR take on Ophelia.

[Summer Sun]

Slight eastward shift from the 06Z

[Mokidugway]

6 minutes ago, Polar Maritime said:

This mornings Net-Wx MR take on Ophelia.

Smack bang into me ,great  

[Ross Andrew Hemphill]

More of the UK at risk now it's looking like, although just a normal autumnal gale near me (maybe 70mph but not impressive), hopefully something more... 

[tornado tams]

What of the Bristol channel ? and the potential of a storm surge.

[karlos1983]

7 minutes ago, Ross Andrew Hemphill said:

More of the UK at risk now it's looking like, although just a normal autumnal gale near me (maybe 70mph but not impressive), hopefully something more... 

A lot of trees still in full leaf though and saturated ground in the NW, so could bring a fair few trees down, travel distruption pretty likely given the time of day as well. 

[SnowBear]

10 minutes ago, tornado tams said:

What of the Bristol channel ? and the potential of a storm surge.

Been thinking on this myself, one of the biggest tidal ranges in the world. It's possible it won't cause much in the Bristol channel itself as the winds at the moment will be parallel/offshore (eastern side of the storm), but could be interesting in the Irish sea and eastern coast of Ireland. This could change with any eastward movement of Ophelia's track. Most models a showing a fairly tight track forecast so unlikely.

Been watching surf forecasts as time allows, most surf beaches in Cornwall, Devon and South Wales forecasting dangerous waves mid Monday. 10m+ in Southern Ireland.

Just as a side, 10-13m waves are not unusual off the coast of Ireland, some of the biggest waves in the world can happen here, though this tends to be more off the west/north west coast during winter storms with the driving winds from Canada. The record is somewhere near 20m/60'. What is dangerous is it being more inshore.

[Guest]

29 minutes ago, karlos1983 said:

A lot of trees still in full leaf though and saturated ground in the NW, so could bring a fair few trees down, travel distruption pretty likely given the time of day as well. 

I've really only seen the city planted trees out of leaf now, would certainly be interesting in the countryside and roads adorned with woods. Might also give The Dark Hedges a thrashing

[Lynxus]

Neighbours fences have been in disrepair for many years but wont do much about it.

 

Maybe this will remove them entirely.

 

[The PIT]

Interesting report by noaa. The hurricane is keeping it's strength for now and atmospheric conditions combined with warmer than average sea temps look like helping it to be a very powerful extropical low. Hopefully we are not sleep walking into a emergency situation.

 

[SnowBear]

Just as an addition to my last post, Monday night is the time to watch any surge for the Bristol Channel, winds by then have backed to SW, but equally easing at the same time.

[toggerob]

In response to the *slightly* strengthening of Ophelia, NHC have also extended the cone further northwards taking it as a extratropical-storm all the way through northern Scotland and past the Shetland Isles.