490
WTNT34 KNHC 262042
TCPAT4

BULLETIN
Hurricane Helene Advisory Number 14
NWS National Hurricane Center Miami FL AL092024
500 PM EDT Thu Sep 26 2024

...HELENE IS A VERY DANGEROUS AND LARGE MAJOR HURRICANE...

...DAMAGING HURRICANE WINDS AND CATASTROPHIC STORM SURGE
EXPECTED TO BEGIN IN THE FLORIDA BIG BEND THIS EVENING...

SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION ----------------------------------------------
LOCATION...27.9N 84.6W
ABOUT 130 MI...205 KM W OF TAMPA FLORIDA
ABOUT 175 MI...280 KM S OF TALLAHASSEE FLORIDA
MAXIMUM SUSTAINED WINDS...125 MPH...205 KM/H
PRESENT MOVEMENT...NNE OR 25 DEGREES AT 23 MPH...37 KM/H
MINIMUM CENTRAL PRESSURE...951 MB...28.09 INCHES

WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
* Mexico Beach eastward and southward to Flamingo
* Tampa Bay
* Charlotte Harbor

A Hurricane Warning is in effect for...
* Anclote River to Mexico Beach

A Hurricane Watch is in effect for...
* Englewood to Anclote River, including Tampa Bay

A Tropical Storm Warning is in effect for...
* Florida Keys, including the Dry Tortugas
* Flamingo to Anclote River, including Tampa Bay
* West of Mexico Beach to the Okaloosa/Walton County Line
* Flamingo northward to Little River Inlet
* Lake Okeechobee

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline. For
a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov. This is a life-threatening situation. Persons
located within these areas should take all necessary actions to
protect life and property from rising water and the potential for
other dangerous conditions. Promptly follow evacuation and other
instructions from local officials.

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. Preparations to protect life
and property should be rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.

DISCUSSION AND OUTLOOK
----------------------
At 500 PM EDT (2100 UTC), the eye of Hurricane Helene was located
near latitude 27.9 North, longitude 84.6 West. Helene is moving
toward the north-northeast near 23 mph (37 km/h). A continued fast
motion to the north-northeast is expected through landfall in the
Florida Big Bend this evening. After landfall, Helene is expected to
turn northwestward and slow down over the Tennessee Valley on
Friday and Saturday.

Maximum sustained winds have increased to near 125 mph (205 km/h)
with higher gusts. Helene is a category 3 hurricane on the
Saffir-Simpson Hurricane Wind Scale. Additional strengthening is
expected, and Helene will likely be an extremely dangerous category
4 hurricane at landfall. Weakening is expected after Helene moves
inland, but the fast forward speed will allow strong, damaging
winds, especially in gusts, to penetrate well inland across the
southeastern United States, including over the higher terrain of the
southern Appalachians.

Hurricane-force winds extend outward up to 60 miles (95 km) from the
center and tropical-storm-force winds extend outward up to 310 miles
(500 km). A weather station at Venice Municipal Airport recently
reported a sustained wind of 46 mph (74 km/h) with a gust of 69 mph
(111 km/h). Another observation near Venice Beach reported a
sustained wind of 51 mph (82 km/h) with a gust to 66 mph (106 km/h).

The estimated minimum central pressure based on data from the Air
Force Hurricane Hunters is 951 mb (28.09 inches).

HAZARDS AFFECTING LAND
----------------------
Key Messages for Helene can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC
and on the web at hurricanes.gov/text/MIATCDAT4.shtml

STORM SURGE: The combination of a life-threatening storm surge and
the tide will cause normally dry areas near the coast to be flooded
by rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide...

Carrabelle, FL to Suwannee River, FL...15-20 ft
Apalachicola, FL to Carrabelle, FL...10-15 ft
Suwannee River, FL to Chassahowitzka, FL...10-15 ft
Chassahowitzka, FL to Anclote River, FL...8-12 ft
Indian Pass, FL to Apalachicola, FL...6-10 ft
Anclote River, FL to Middle of Longboat Key, FL...5-8 ft
Tampa Bay...5-8 ft
Middle of Longboat Key, FL to Englewood, FL...4-7 ft
East of Mexico Beach, FL to Indian Pass, FL...3-5 ft
Englewood, FL to Flamingo, FL...3-5 ft
Charlotte Harbor...3-5 ft

The deepest water will occur along the immediate coast near and to
the east of the landfall location, where the surge will be
accompanied by large and dangerous waves. Surge-related flooding
depends on the relative timing of the surge and the tidal cycle,
and can vary greatly over short distances. For information
specific to your area, please see products issued by your local
National Weather Service forecast office.

For a complete depiction of areas at risk of storm surge inundation,
please see the National Weather Service Peak Storm Surge Graphic,
available at hurricanes.gov/graphics_at4.shtml?peakSurge.

WIND: Hurricane conditions are expected within the hurricane warning
area this evening. Tropical storm conditions are occurring in the
southern and central Florida, and these conditions are expected to
spread northward across the tropical storm warning areas in the
Southeastern U.S. through early Friday. Strong, damaging winds,
especially in gusts, will likely penetrate as far inland as the
higher terrain of the southern Appalachians.

RAINFALL: Over portions of the Southeastern U.S. into the Southern Appalachians, Helene is expected to produce total rain accumulations
of 6 to 12 inches, with isolated totals around 20 inches. This
rainfall will likely result in catastrophic and potentially
life-threatening flash and urban flooding, along with significant
river flooding. Numerous significant landslides are expected in
steep terrain across the southern Appalachians.

For a complete depiction of forecast rainfall associated with
Hurricane Helene, please see the National Weather Service Storm
Total Rainfall Graphic, available at
hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk
graphic at hurricanes.gov/graphics_at4.shtml?ero.

For a list of rainfall observations (and wind reports) associated
this storm, see the companion storm summary at WBCSCCNS4 with the
WMO header ACUS44 KWBC or at the following link: http://www.wpc.ncep.noaa.gov/discussions/nfdscc4.html .

TORNADOES: The risk for several tornadoes continues through
tonight over much of Florida, southeast Georgia, central and
southern South Carolina, and southern North Carolina. The tornado
risk will continue Friday across the Carolinas and southern
Virginia.

SURF: Swells generated by Helene will affect much of Florida and
the coasts of Georgia and the Carolinas during the next couple of
days. These swells are likely to cause life-threatening surf and
rip current conditions. Please consult products from your local
weather office.

NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.

$$
Forecaster Cangialosi

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