ATL: FLORENCE - Post-Tropical - Discussion

[sponger]

Florence is strengthening a lot quicker than anticipated, I wouldn't be surprised if recon finds a 110kt+ storm. Florence is taking full advantage of its excellent structure, increasing SSTs, and low wind shear. The satellite presentation reminds me of a WPAC super typhoon. This *could* hit 140 knots.

https://i.imgur.com/IjdvUxr.jpg

If Florence were to attain Cat-5 status, it would represent the northernmost Cat-5 in the Atlantic basin since 1851. As climate change induces warmer SSTs globally, Florence could further confirm the northward shift in intense tropical cyclones over the past several decades. At this point, given the faster-than-expected short-term intensification, I think low-end Cat-5 status is increasingly probable. I think the indications are that the landfall will occur in NC between Oak Island and Morehead City.

1851 was the end of a 500 year ice age so your reasoning on warm SST's is quite flawed.

[galaxy401]

Ugh definitely a cat 4 now. Expect a special advisory shortly.

Edit: Yep, it just got published!

[northjaxpro]

Savannah was placed back just inside the cone of uncertainty by NHC for direct landfall on the very extrerme southern edge per 11 a.m. advisory for a subtle adjustment.

There is no such thing as a cone of uncertainty. The cone is the historical error within which 2/3 of storms will fall. That means that, for any given storm, there is a 1/3 chance of the storm falling outside of that cone. Just because you are outside of the cone does not mean that the NHC doesn't think you could see a direct hit. In every single forecast they say that a direct hit outside of the cone is very possible.

Some call it the cone of confusion

Cone of error. Cone of uncertainty etc.. Cone of confusion. lol.. Whatever you want to call it..

[PavelGaborik10]

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.

Recon just reported 945.0 mb extrapolated surface pressure in the eye, 131 knots in NE eyewall.

131 Knots at Flight level, I was talking surface.

[ronjon]

She better start gaining some latitude soon!

http://rammb.cira.colostate.edu/ramsdis/online/loop.asp?data_folder=tropical/tropical_ge_4km_visir2_floater_1&width=640&height=480&number_of_images_to_display=12

[xtyphooncyclonex]

If Florence does end up becoming a category five, the 2018 Atlantic hurricane season would be the third in a row to feature at least one category five hurricane.

[supercane4867]

If she EWRC's as she's leaving the best condition zone, she might not be able to re-intensify on final approach. Could be a bullet dodge...if you consider 120mph over 150mph a bullet dodge.

At any rate...she is very Harvey like right now; small, tight, powerful wind core. Localized. An EWRC (or worse, two) would probably double or triple the width of the major hurricane force winds.

I think she will complete one EWRC before the best condition, then maybe another EWRC before landfall. The secondary peak after the first EWRC maybe much stronger than she is today.

[cheezyWXguy]

If she EWRC's as she's leaving the best condition zone, she might not be able to re-intensify on final approach. Could be a bullet dodge...if you consider 120mph over 150mph a bullet dodge.

At any rate...she is very Harvey like right now; small, tight, powerful wind core. Localized. An EWRC (or worse, two) would probably double or triple the width of the major hurricane force winds.

A large cat 2/3 landfall would be much worse than a compact cat 3/4 landfall, the only exception being in the immediate right-front quadrant of the storm. A larger storm would not only maximize windfield size, but also surge potential and rainfall impacts.

[Shell Mound]

Florence is strengthening a lot quicker than anticipated, I wouldn't be surprised if recon finds a 110kt+ storm. Florence is taking full advantage of its excellent structure, increasing SSTs, and low wind shear. The satellite presentation reminds me of a WPAC super typhoon. This *could* hit 140 knots.

https://i.imgur.com/IjdvUxr.jpg

If Florence were to attain Cat-5 status, it would represent the northernmost Cat-5 in the Atlantic basin since 1851. As climate change induces warmer SSTs globally, Florence could further confirm the northward shift in intense tropical cyclones over the past several decades. At this point, given the faster-than-expected short-term intensification, I think low-end Cat-5 status is increasingly probable. I think the indications are that the landfall will occur in NC between Oak Island and Morehead City.

1851 was the end of a 500 year ice age so your reasoning on warm SST's is quite flawed.

I meant that SSTs are currently warming relative to what they were in the early twentieth century. I apologise for taking things off topic.

[NDG]

Actual pressure 947mb measured by dropsonde.

[CrazyC83]

I'd expect a special advisory soon with a 115 kt intensity. Could they bump the peak up to cat 5?

[tatertawt24]

This may have already been posted, but this is a great collection of different Florence data, all compiled in one neat place:

http://rammb.cira.colostate.edu/products/tc_realtime/storm.asp?storm_identifier=AL062018

[TexWx]

Just curious, are there any links to live news feeds, etc?

Or is there a thread for that?

Thanks in advance.

[Shell Mound]

I'd expect a special advisory soon with a 115 kt intensity. Could they bump the peak up to cat 5?

https://www.nhc.noaa.gov/text/refresh/MIATCUAT1+shtml/101556.shtml

368
WTNT61 KNHC 101556
TCUAT1

Hurricane Florence Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL062018
1200 PM AST Mon Sep 10 2018

...FLORENCE BECOMES A CATEGORY FOUR HURRICANE...

Data from a NOAA Hurricane Hunter aircraft indicate that Florence
has continued to rapidly stregthen and has maximum sustained winds
near 130 mph (195 km/h). The latest minimum central pressure based
on data from the aircraft is 946 mb (27.93 inches).


SUMMARY OF 1200 PM AST...1600 UTC...INFORMATION
---------------------------------------------------
LOCATION...25.0N 60.2W
ABOUT 575 MI...925 KM SSE OF BERMUDA
ABOUT 1230 MI...1985 KM ESE OF CAPE FEAR NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...130 MPH...195 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...946 MB...27.93 INCHES

$$
Forecaster Blake

[plasticup]

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

Recon just reported 945.0 mb extrapolated surface pressure in the eye, 131 knots in NE eyewall.

131 Knots at Flight level, I was talking surface.

True, true. I was misreading the data file.

[Ken711]

If she EWRC's as she's leaving the best condition zone, she might not be able to re-intensify on final approach. Could be a bullet dodge...if you consider 120mph over 150mph a bullet dodge.

At any rate...she is very Harvey like right now; small, tight, powerful wind core. Localized. An EWRC (or worse, two) would probably double or triple the width of the major hurricane force winds.

When you say small wind field, how does it compare to Irma? And couldn't Florence expand further?

[sponger]

Center dropsonde 947mb/9kt confirms the extrapolated pressure estimates.

Wow!

[cycloneye]

Hurricane Florence Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL062018
1200 PM AST Mon Sep 10 2018

...FLORENCE BECOMES A CATEGORY FOUR HURRICANE...

Data from a NOAA Hurricane Hunter aircraft indicate that Florence
has continued to rapidly stregthen and has maximum sustained winds
near 130 mph (195 km/h). The latest minimum central pressure based
on data from the aircraft is 946 mb (27.93 inches).


SUMMARY OF 1200 PM AST...1600 UTC...INFORMATION
---------------------------------------------------
LOCATION...25.0N 60.2W
ABOUT 575 MI...925 KM SSE OF BERMUDA
ABOUT 1230 MI...1985 KM ESE OF CAPE FEAR NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...130 MPH...195 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...946 MB...27.93 INCHES

$$
Forecaster Blake

[GCANE]

 https://twitter.com/TropicalTidbits/status/1039181055801081857

[plasticup]

If she EWRC's as she's leaving the best condition zone, she might not be able to re-intensify on final approach. Could be a bullet dodge...if you consider 120mph over 150mph a bullet dodge.

At any rate...she is very Harvey like right now; small, tight, powerful wind core. Localized. An EWRC (or worse, two) would probably double or triple the width of the major hurricane force winds.

When you say small wind field, how does it compare to Irma? And couldn't Florence expand further?

Much smaller than Irma was at her peak over the Leeward Islands, and much much smaller than when she arrived in Florida. Florence will certainly expand between here and landfall, although exactly how much is hard to predict.

Irma wind history:


Florence wind history: