ATL: FLORENCE - Post-Tropical - Discussion

[Exalt]

Everyone over at William & Mary are making evac. plans!

[plasticup]

Classic look of deep convection rolling around the eyewall...once that solidifies at a -60º to -80º ring, we could be looking at RI up to a strong 4, maybe a weak 5.

Good timing that recon is en route. Should be arriving in an hour or so. I think they'll find 125-130 knots by then.

[plasticup]

[PavelGaborik10]

"Florence well organized but why isn't the convection deeper such as say its counterpart near Africa? Environment.
Note the visible imagery how Florence's presentation is flat/smooth. Great organization but not great height into the atmosphere."

"They went to go find out some things. For steering, environment, et al.
One thing obvious is the environment is dry. It just is. Throughout the column. So a well organized Florence is strong & strengthening but so far it hasn't been explosive due to the abundance of drier air."

"Enviro aloft also preventing outflow from expanding. Too many features remain in the stream flow to allow expansion as yet. Until that changes slow & measured strengthening.
Also the ridge is being lifted by the Caribbean surge & the ridge is moving east. Keeps the N/E gate open."

"Based off GFS but just 48hrs out most models the same.
You get the breathing room finally and the storm can deepen. At same time those features shown evolve to allow the northern gate to be open to target more eastern NC barrier islands. Just can't dismiss this idea."

Not so sure I would considering jumping up from a category 1 Hurricane from when I went to sleep last night, to a 3 but the time I awake "slow and measured" strengthening, but that's just me.

[Blinhart]

Classic look of deep convection rolling around the eyewall...once that solidifies at a -60º to -80º ring, we could be looking at RI up to a strong 4, maybe a weak 5.

Dry air would have to try real hard to penetrate this thing...SHIPS has shear very low until about D3. Through 60 hours, the highest it gets is 10kts. 18kts at HR 72, increasing to a 25kt maximum at HR108. Now, that's nothing compared to what she was dealing with a few days ago (30-40kts in a much less conducive environment). So 12-18 hours of 15-20kt shear before landfall...might take off a tiny bit. Probably not that much.

SHIPS notes how much shear goes into intensity forecast...and it never has a negative effect for the 12z SHIPS.

12z SHIPS is also the most intensive SHIPS run I've seen so far, maxing out at 127kts (131 for LGEM) at HR+60, decreasing to 115kts (that's a cat 4) at landfall. SSTs are 29ºC or higher until landfall. OHC around 30 or higher (lowest of 27).

I don't see any reason this won't be a major hurricane at landfall. Last-minute preparations should be conducted now. We are 3.5 days out. It's go time if you are in the path of this thing.

Totally agree with this, and if her direction of 280 degree does increase anytime soon, they will have to start adjusting the cone to the left.

[chris_fit]

Proof that people are prepping!

[Ken711]

Classic look of deep convection rolling around the eyewall...once that solidifies at a -60º to -80º ring, we could be looking at RI up to a strong 4, maybe a weak 5.

Dry air would have to try real hard to penetrate this thing...SHIPS has shear very low until about D3. Through 60 hours, the highest it gets is 10kts. 18kts at HR 72, increasing to a 25kt maximum at HR108. Now, that's nothing compared to what she was dealing with a few days ago (30-40kts in a much less conducive environment). So 12-18 hours of 15-20kt shear before landfall...might take off a tiny bit. Probably not that much.

SHIPS notes how much shear goes into intensity forecast...and it never has a negative effect for the 12z SHIPS.

12z SHIPS is also the most intensive SHIPS run I've seen so far, maxing out at 127kts (131 for LGEM) at HR+60, decreasing to 115kts (that's a cat 4) at landfall. SSTs are 29ºC or higher until landfall. OHC around 30 or higher (lowest of 27).

I don't see any reason this won't be a major hurricane at landfall. Last-minute preparations should be conducted now. We are 3.5 days out. It's go time if you are in the path of this thing.

Totally agree with this, and if her direction of 280 degree does increase anytime soon, they will have to start adjusting the cone to the left.

Why would they need to adjust the cone to the left?

[supercane4867]

Just a reminder that Flo is still well away from the warmest water in her track

[BobHarlem]

@DareCountyEM

A mandatory evacuation order for all visitors & residents on #Hatteras Island will be in effect Monday, September 10 at 12 p.m. A mandatory evacuation for residents and visitors in other areas of Dare County goes into effect beginning Tuesday, September 11 at 7:00 a.m.

 https://twitter.com/DareCountyEM/status/1039156090355806208



 https://twitter.com/DareCountyEM/status/1039156535983845376

[PavelGaborik10]

Classic look of deep convection rolling around the eyewall...once that solidifies at a -60º to -80º ring, we could be looking at RI up to a strong 4, maybe a weak 5.

Good timing that recon is en route. Should be arriving in an hour or so. I think they'll find 125-130 knots by then.

Seems a tad excessive. I think we'll see somewhere around 105-115(max)KNOTS.

[Blinhart]

Classic look of deep convection rolling around the eyewall...once that solidifies at a -60º to -80º ring, we could be looking at RI up to a strong 4, maybe a weak 5.

Dry air would have to try real hard to penetrate this thing...SHIPS has shear very low until about D3. Through 60 hours, the highest it gets is 10kts. 18kts at HR 72, increasing to a 25kt maximum at HR108. Now, that's nothing compared to what she was dealing with a few days ago (30-40kts in a much less conducive environment). So 12-18 hours of 15-20kt shear before landfall...might take off a tiny bit. Probably not that much.

SHIPS notes how much shear goes into intensity forecast...and it never has a negative effect for the 12z SHIPS.

12z SHIPS is also the most intensive SHIPS run I've seen so far, maxing out at 127kts (131 for LGEM) at HR+60, decreasing to 115kts (that's a cat 4) at landfall. SSTs are 29ºC or higher until landfall. OHC around 30 or higher (lowest of 27).

I don't see any reason this won't be a major hurricane at landfall. Last-minute preparations should be conducted now. We are 3.5 days out. It's go time if you are in the path of this thing.

Totally agree with this, and if her direction of 280 degree does increase anytime soon, they will have to start adjusting the cone to the left.

Why would they need to adjust the cone to the left?

Because she is staying further South than forecasted, so she will be coming in further South which would cause the cone to move Left.

[Cyclenall]

Not so sure I would considering jumping up from a category 1 Hurricane from when I went to sleep last night, to a 3 but the time I awake "slow and measured" strengthening, but that's just me.

I agree with that assessment, but I would use the word steady-fast strengthening instead. The deepening doesn't seem all that explosive to me after following the Epac this and other seasons. I still think it reaches that peak intensity of 130-140 knots regardless.

[cycloneye]

 https://twitter.com/TropicalTidbits/status/1039157380234338305

[Blinhart]

Classic look of deep convection rolling around the eyewall...once that solidifies at a -60º to -80º ring, we could be looking at RI up to a strong 4, maybe a weak 5.

Good timing that recon is en route. Should be arriving in an hour or so. I think they'll find 125-130 knots by then.

Seems a tad excessive. I think we'll see somewhere around 105-115(max)KNOTS.

I was thinking between 120-125 Knots right around 145 MPH due to Stellite Presentation.

[Ken711]

Totally agree with this, and if her direction of 280 degree does increase anytime soon, they will have to start adjusting the cone to the left.

Why would they need to adjust the cone to the left?

Because she is staying further South than forecasted, so she will be coming in further South which would cause the cone to move Left.

But if it's a more intense hurricane wouldn't that track faster and neglect any interim South movements?

[Vdogg]

P-3 plane has left Bermuda for reconnaissance of the storm. Great timing, as the satellite presentation has improved so much and this is likely a Cat 3/4 storm. And some location fixes will help is establish whether she is making the WNW turn as expected.

NHC stated in their last advisory that it has already turned WNW

[jdjaguar]

Stronger ridging obviously in place. The afternoon Euro run will tell a lot. My brothers wife is pregnant with 2 kids home alone in Wilmington. Told her to leave tonight to stay with family as tomorrow the coastal zoo begins. Parents in Wilmington are staying put which is a good idea if not in a flood zone. Evacuation is going to be far over done and I expect parking lot conditions by Tues afternoon.

They reverse the eastbound lane on I-40 during evacuations at least

Quite true. NC and SC are pros at this while Florida pretends that its impossible and does not help. However, I would not expect any Contra flow help until Wed at the earliest.

Florida is a peninsula. A logistical nightmare, and essentially impossible to evacuate an IRMA event.

[jlauderdal]

Why would they need to adjust the cone to the left?

Because she is staying further South than forecasted, so she will be coming in further South which would cause the cone to move Left.

But if it's a more intense hurricane wouldn't that track faster and neglect any interim South movements?

not necessarily, hurricane Andrew went due west....the whole pole ward movement thing for strong canes is over hyped, seen many majors head west or wsw

[Blinhart]

Why would they need to adjust the cone to the left?

Because she is staying further South than forecasted, so she will be coming in further South which would cause the cone to move Left.

But if it's a more intense hurricane wouldn't that track faster and neglect any interim South movements?

Not necessarily, it all depends on the Ridge to the North.

[edu2703]

 https://twitter.com/SFNCwx/status/1039157590381551616