ATL: FLORENCE - Post-Tropical - Discussion

[mcheer23]

Cat 4 wow

[Ken711]

What was Andrew at landfall and across FL?

[GCANE]

Still cruisin down Hwy 25N, westbound.

[CrazyC83]

What was Andrew at landfall and across FL?

5 at landfall. Only weakened to 4 as it departed as it moved across the Everglades for the most part.

[Hurricane Andrew]

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?

Yes, Florence can expand! Eyewall Replacement Cycles (EWRCs) often expand the Winfield. As for Irma...uh...let me dig up an advisory.

This was from the 2AM advisory on the 10th, the day of landfall:

Code: Select all

Hurricane-force winds extend outward up to 70 miles (110 km) from
the center, and tropical-storm-force winds extend outward up to 205
miles (335 km).

This is from Florence's 11AM advisory:

Code: Select all

Hurricane-force winds extend outward up to 30 miles (45 km) from the
center and tropical-storm-force winds extend outward up to 140 miles
(220 km).

Much smaller at this time.

[MississippiWx]

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

Florence isn’t even over the warmest SSTs yet. Upper levels only get more favorable. I see a Cat 5 in the making.

[GCANE]

 https://twitter.com/StuOstro/status/1039182116469268480

[sponger]

What was Andrew at landfall and across FL?

165 mph and a minimum central pressure of 922 millibars

[Ubuntwo]

What was Andrew at landfall and across FL?

Andrew made landfall at 165MPH, after it passed over Florida it weakened to 130MPH.

[AtlanticWind]

A shift east on 12z GFS near outer banks or just offshore

[Cumulonimbus_Ca]

Android phones can measure barometric pressure where they are - I've made an app that can use all this data collected together from different phones to make 'virtual weather stations'. I'm interested in measuring Florence when it landfalls - anyone who is safely near the storm would be able to record incredible pressure drops as it approaches! Here is the link if you're curious: https://play.google.com/store/apps/deta ... er.android And since the sensor data could be valuable, the code for the sensor part of the app is open source: https://github.com/JacobSheehy/AllClearSensorLibrary So you can include it in any Android app to collect and analyze the barometric pressure data. Cheers!

[MGC]

12Z GFS recurves just east of Hatteras. Yes, impressive hurricane. Intensity should fluctuate due to EWRC. Some major hurricanes have a bunch of them some only a few. Hope the GFS is correct....MGC

[northjaxpro]

Correct me if I am in error, but is Hugo still the strongest North Atlantic tropical cyclone to make U.S. landfall north of 30 degrees Latitude?

It measured 918 mb at one time on its approach to the SC coast in 1989. Remember it like yesterday tracking him.

[meriland29]

Question....wouldn't this much intensity this quickly leave her vulnerable to a sooner-than-expected EWRC? Wouldn't that displace her future strength if it happened over these waters?

[GCANE]

Product: NOAA Vortex Message (URNT12 KWBC)
Transmitted: 10th day of the month at 16:04Z


A. Time of Center Fix: 10th day of the month at 15:35:18Z
B. Center Fix Coordinates: 24.99N 60.14W

D. Minimum Sea Level Pressure: 947mb (27.97 inHg)
E. Dropsonde Surface Wind at Center: From 50° at 9kts (From the NE at 10mph)
F. Eye Character: Closed
G. Eye Shape & Diameter: Circular with a diameter of 12 nautical miles (14 statute miles)
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 113kts (130.0mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 6 nautical miles to the SW (235°) of center fix at 15:33:37Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 119kts (136.9mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 12 nautical miles (14 statute miles) to the NE (54°) of center fix at 15:38:13Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 14°C (57°F) at a pressure alt. of 2,391m (7,844ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 20°C (68°F) at a pressure alt. of 2,785m (9,137ft)

Remarks Section:

Maximum Flight Level Wind: 132kts (~ 151.9mph) which was observed 12 nautical miles (14 statute miles) to the NE (54°) from the flight level center at 15:38:15Z

[cycloneye]

Who wants to continue the posting of the data of this important mission?

I really can't continue. Someone come.

[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?

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:

Thanks.

[Exalt]

Would I need to or should I evacuate if I live in Williamsburg? If so by when? I would think the Hampton Roads area would begin evacuations sometime tomorrow, but I do not exactly know.

The sooner the better. The coverage will pick up soon and people will really start hauling. You don't want to get stuck in that mass of traffic. I would leave today.

Yeah I have a plan, I just wasn’t sure if it was warranted for the Chesapeake area or not but I could easily see us getting hurricane force winds or at least a lot of flooding from the stalling that may occur.

[CrazyC83]

Correct me if I am in error, but is Hugo still the strongest North Atlantic tropical cyclone to make U.S. landfall north of 30 degrees Latitude?

It measured 918 mb at one time on its approach to the SC coast in 1989. Remember it like yesterday tracking him.

Camille made landfall at 30.3N with 900 mb, but that was in the Gulf. Hugo is the strongest on the east coast (934 mb / 120 kt).

[psyclone]

Individual models may be flopping around but notice what isn't...the NHC track. it's shown remarkable consistency since it began depicting landfall.