000
WTNT34 KNHC 262353
TCPAT4
BULLETIN
Hurricane Helene Intermediate Advisory Number 14A
NWS National Hurricane Center Miami FLORIDA AL092024
8:00 P.M. Eastern Daylight Time Thu Sep 26 2024
EXTREMELY DANGEROUS HURRICANE HELENE NEARING THE NORTHEAST GULF COAST
CATASTROPHIC STORM SURGE AND LIFE-THREATENING WINDS EXPECTED IN THE FLORIDA BIG BEND AREA
SUMMARY OF 8:00 P.M. Eastern Daylight Time 00:00 Coordinated Universal Time INFORMATION
LOCATION 28.7N 84.3W
ABOUT 80 MI 125 KM WSW OF CEDAR KEY FLORIDA
ABOUT 115 MI 190 KM S OF TALLAHASSEE FLORIDA
MAXIMUM SUSTAINED WINDS 130 MPH 215 KM/H
PRESENT MOVEMENT NNE OR 25 DEGREES AT 23 MPH 37 KM/H
MINIMUM CENTRAL PRESSURE 942 Millibar, 27.82 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.
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.
DISCUSSION AND OUTLOOK
At 8 :00 P.M. Eastern Daylight Time (0000 Coordinated Universal Time), the eye of Hurricane Helene was located near latitude 28.7 North, longitude 84.3 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 in a few hours. After landfall, Helene is
expected to turn northwestward and slow down over the Tennessee
Valley on Friday and Saturday.
Maximum sustained winds are near 130 mph (215 km/h) with higher
gusts. Helene is a category 4 hurricane on the Saffir-Simpson
Hurricane Wind Scale. Some additional strengthening is possible
before the center reaches the coast in a few hours. 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). Albert Whitted airport in St. Petersburg, Florida
reported a sustained wind of 53 mph (85 km/h) with a gust to 76 mph
(122 km/h).
The minimum central pressure estimated from Hurricane Hunter
aircraft observations is 942 Millibar, (27.82 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, FLORIDA to Suwannee River, FLORIDA 15-20 feet
Apalachicola, FLORIDA to Carrabelle, FLORIDA 10-15 feet
Suwannee River, FLORIDA to Chassahowitzka, FLORIDA 10-15 feet
Chassahowitzka, FLORIDA to Anclote River, FLORIDA 8-12 feet
Indian Pass, FLORIDA to Apalachicola, FLORIDA 6-10 feet
Anclote River, FLORIDA to Middle of Longboat Key, FLORIDA 5-8 feet
Tampa Bay 5-8 feet
Middle of Longboat Key, FLORIDA to Englewood, FLORIDA 4-7 feet
East of Mexico Beach, FLORIDA to Indian Pass, FLORIDA 3-5 feet
Englewood, FLORIDA to Flamingo, FLORIDA 3-5 feet
Charlotte Harbor 3-5 feet
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 beginning within the hurricane
warning area. When the eye comes ashore, people are reminded to not
venture out into the relative calm, as hazardous winds will increase
very quickly when the eye passes. Tropical storm conditions are
occurring in southern and central Florida, and these conditions will
be spreading 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:
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 complete advisory at 11 :00 P.M. Eastern Daylight Time.
$$
Forecaster Pasch
Originally Posted at:
NATIONAL HURRICANE CENTER and CENTRAL PACIFIC HURRICANE CENTER
At The NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
