Hurricane Florence

[knocker]

Advisory 27: Florence Should Remain a Powerful Hurricane For Several More Days.

https://www.nhc.noaa.gov/cyclones/

And current sat

https://www.tropicaltidbits.com/sat/satlooper.php?region=06L&product=wv-mid

Edited September 6, 2018 by knocker

[Iceberg]

Shear is finally eating away at her, dvorak comes all the way down to a cat 2 now. However shear isn’t due to last long and the eye is staying intact. 

Ec 00z again has landfall probably as a high end large cat 4 with 945mb pressure. Potential landfall is only 7 days away. But obviously 2 days of chopping and changing yet. 

[summer blizzard]

NHC discussion now forecasting 'significant strengthening' by day, cat 4 at a minimum.

Gfs stalls just off the coast, euro and gem hit. Ukmo holds hard on the westerly track to the point that it is headed for the Bahamas. Reminds me a bit of Francis 04.

[Iceberg]

METO and Mogreps 00z. It does indeed. Florida style. 

Waiting for ec ens. 

[summer blizzard]

5 minutes ago, Iceberg said:

METO and Mogreps 00z. It does indeed. Florida style. 

Waiting for ec ens. 

What is Mogreps based from?

[Iceberg]

mogreps is essentially the meto ens suite so will nearly always follow the meto ops

[MattTarrant]

NHC (Advisory 29) Key points:

. Increase in vertical shear (25 - 30kt estimates) has caused degradation of Florence's structure (Intensity set at 90kt/ Category 2)

. Deep convection no longer symmetric (low level circulation visible)

. Nuances of environmental shear forecasting causing complications in intensity predictions 

. Continued weakening over the next 24hrs likely as strong vertical shear continues (Category 2 > Category 1)

. Movement has slowed (9kt), with a NW movement

. Development of mid - level ridge will steer Florence (Post 24 - 36hrs) increasingly westwards 

. Florence expected to regain major hurricane status by day 4/5 (Re - Strengthening post 36hrs)

. Movement post day 4 uncertain with major model suites diverging on ridge strength (ECMWF & UKMET vs GFS & HWRF)

 

 

 

 

[Lauren]

Florence is going to be a nailbiter for sure. Bermuda looking to be in an unfortunate position. 

[Iceberg]

Gfs ops 12z has joined the other models on a us mainland hit. This time around New York/Long Island. 

It then does a 360 loop, back down , gains some strength and goes pass again. 

Not the final solution imho. 

I am personally going for a North Carolina hit, out of gut and nothing else. 

 

Re Bermuda it should pass just to the south. With a bit of luck the small size should mean that Bermuda escapes any real affects. 

[summer blizzard]

UKMO capitulates to Euro and GEM.

 

[Iceberg]

Ec 12z maintains some consistency. 

940-950mb and landfall in North Carolina. Then a travel up the coast. 

[MattTarrant]

1 hour ago, Iceberg said:

Gfs ops 12z has joined the other models on a us mainland hit. This time around New York/Long Island. 

It then does a 360 loop, back down , gains some strength and goes pass again. 

Not the final solution imho. 

I am personally going for a North Carolina hit, out of gut and nothing else. 

 

Re Bermuda it should pass just to the south. With a bit of luck the small size should mean that Bermuda escapes any real affects. 

The Latest ECM confirms this development (at least within the operationals) that landfall is increasingly likely, indeed a major hurricane as well

Edit: Beat me to it 

Edited September 6, 2018 by MattTarrant

[summer blizzard]

Euro heads wnw and hits the outer banks before doing a loop the loop.

 

[Iceberg]

Ec ens. 

In the last few frames she has recovered the smallest of amounts. Dvorak don’t really indicate a hurricane even at the moment but only another 12-24 hrs of punishing shear. 

Upwelljng of cooler waters under 28c ssts is also a problem imho as convection is limited regardless of shear. 

[MattTarrant]

 

[Iceberg]

Latest nhc update just released. 

Keeps as a cat 1 hurricane, just !

“

Vertical shear has taken its toll on Florence today as evidenced by
a continued degradation of the overall cloud pattern.  The
circulation appears tilted, with the low-level center partially
exposed to the southwest of the deep convection.  Subjective and
objective Dvorak Current Intensity (CI) numbers have fallen, and a
blend of the various estimates supports an initial intensity of 70
kt.

The intensity forecast is relatively straightforward in the
short-term as shear is expected to remain strong, which should
continue Florence's weakening trend, potentially taking the system
below hurricane strength.  By 24 hours, vertical shear is forecast
to decrease, and the SSTs gradually warm along the forecast track.
Assuming the overall circulation remains intact, Florence shouldn't
have any problems restrengthening beginning in a day or so. In
fact, guidance suggests that Florence could once again become a
major hurricane in 4 or 5 days. “

[Lauren]

This is looking to hit the East Coast more and more with every run....

[summer blizzard]

GFS18Z is a proper recurve/Outer Banks at best. 

[knocker]

 

Edited September 7, 2018 by knocker

[Iceberg]

Now back to tropical storm status. ADT dvorak has her at a low end ts. Personally I don’t think thats fair. Dvorak can struggle in these situations a bit. 

Gfs still goes for a close shave but it’s beej pretty dire. The nhc path has mean trying to Tread between gfs and ec but every single run has been shifting westward as gfs continues to lag. Florence is now due to be well south and west of Bermuda for example now. 

Shear has been relentless.

Just imho, but I think shear has lessened in the last hr or so. Precip  is just starting to appear, to the sw and outflow is no longer being quite as strangled. 

Today might show an steady improvement. 

Also today and tomorrow should show how far due west or even just south of west Florence will travel. 

[Iceberg]

Ec dribbling out and shows a further move south and west. 

[Lauren]

I understand storms move at different speeds but on average how long would 93L take to reach the Caribbean from now if it took a fairly straight track?

[karyo]

Proper landfall according to the ECM and it looks like the UKMO would show something similar judging by the 144 hour chart. Does anybody here know what the UKMO 168 hours show?

[Iceberg]

Gfs 06 came round to the meto and ec with a Friday/Saturday landfall and then inland a little. 

Currently shear is def. moving from sw quad to se quad. Personally I think she’s looking a bit better. Ready to pick up in Ernest tomorrow. 

[Iceberg]

Florence continues to improve. Dvorak chart below shows this clearly and the corner has been turned. Say loops confirm better outflow and a slight ssw movement. 

Gfs can no longer avoid this movement and 12z continues the model turn around with a firm NC hit. Although not nailed on, the models are certainly forming up on this enough for the NC coastline to start to take some precautions.