Atlantic Hurricane Feed

Hurricane Helene Public Advisory

Published Date and Time: 2024-09-25 13:52:02



790 
WTNT34 KNHC 251751
TCPAT4

BULLETIN
Hurricane Helene Intermediate Advisory Number 9A
NWS National Hurricane Center Miami FL       AL092024
100 PM CDT Wed Sep 25 2024

...HELENE MOVING INTO THE SOUTHEASTERN GULF OF MEXICO...
...PREPARATIONS TO PROTECT LIFE AND PROPERTY FROM STORM SURGE AND 
DAMAGING WINDS ALONG THE FLORIDA BIG BEND COAST SHOULD BE RUSHED TO 
COMPLETION TODAY...


SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...22.0N 86.4W
ABOUT 110 MI...175 KM NNE OF COZUMEL MEXICO
ABOUT 480 MI...775 KM SSW OF TAMPA FLORIDA
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...NNW OR 345 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...980 MB...28.94 INCHES


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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
* Indian Pass southward to Flamingo
* Tampa Bay
* Charlotte Harbor

A Hurricane Warning is in effect for...
* Anclote River to Mexico Beach
* Cabo Catoche to Tulum, Mexico including Cozumel

A Storm Surge Watch is in effect for...
* West of Indian Pass to Mexico Beach

A Hurricane Watch is in effect for...
* Cuban province of Pinar del Rio
* 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 South Santee River
* Lake Okeechobee
* Rio Lagartos to Cabo Catoche, Mexico
* Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth

A Tropical Storm Watch is in effect for...
* North of South Santee River to Little River Inlet

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. 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 warning is typically issued
36 hours before the anticipated first occurrence of
tropical-storm-force winds, conditions that make outside
preparations difficult or dangerous.  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 within the next 36 hours.

A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
For a depiction of areas at risk, please see the National Weather
Service Storm Surge Watch/Warning Graphic, available at
hurricanes.gov.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.  A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Additional watches or warnings may be required later today or 
tonight.

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 100 PM CDT (1800 UTC), the center of Hurricane Helene was located
near latitude 22.0 North, longitude 86.4 West.  Helene is moving
toward the north-northwest near 10 mph (17 km/h).  A turn toward the
north and north-northeast with an increase in forward speed is
expected later today through Thursday, bringing the center of Helene
across the eastern Gulf of Mexico and to the Florida Big Bend coast
by Thursday evening.  After landfall, Helene is expected to slow
down and turn toward the northwest over the southeastern United
States Friday and Saturday.

Data from an Air Force Reserve Hurricane Hunter aircraft indicate 
that maximum sustained winds remain near 80 mph (130 km/h) with 
higher gusts.  Strengthening is forecast, and Helene is expected to 
be a major hurricane when it reaches the Florida Big Bend coast 
Thursday evening.  Weakening is expected after landfall, but 
Helene's 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 25 miles (35 km) from
the center and tropical-storm-force winds extend outward up to 275
miles (445 km).  A commercial fishing vessel located near Isla 
Mujeres, Mexico, recently reported a wind of 63 mph (102 km/h).

Dropsonde data indicate that the minimum central pressure has been 
relatively steady during the past few hours and is estimated to be
980 mb (28.94 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 Chassahowitzka, FL...12-18 ft
Apalachicola, FL to Carrabelle, FL...8-12 ft
Chassahowitzka, FL to Anclote River, FL...8-12 ft
Indian Pass, FL to Apalachicola, FL...6-9 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
Englewood, FL to Flamingo, FL...3-5 ft
Charlotte Harbor...3-5 ft

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.

Storm surge could raise water levels by as much as 2 to 4 feet above
normal tide levels in areas of onshore winds along the southern
coast of Pinar del Rio, Cuba, including the Isle of Youth.

Storm surge could raise water levels by as much as 3 to 5 feet above
ground level in areas of onshore winds within the warning area along
the north coast of the Yucatan Peninsula.

WIND: Hurricane conditions are expected within the U.S. hurricane
warning area late Thursday, with tropical storm conditions
beginning Thursday morning.  Tropical storm conditions are
expected in southern Florida later today and will spread northward
across the rest of Florida, Georgia, and South Carolina through
Thursday.  Tropical storm conditions are possible within the
tropical storm watch area in South Carolina beginning on Thursday.

Hurricane conditions, especially in gusts, are expected in the
hurricane warning area in Mexico during the next several hours.
Tropical storm conditions are occurring in the warning area in Cuba,
and hurricane conditions are possible for the western portion of
Cuba today.

RAINFALL: Helene is expected to produce total rain accumulations of
4 to 8 inches over western Cuba, the Cayman Islands, and the
northeast Yucatan Peninsula, with isolated totals around 12 inches.
This rainfall brings a risk of considerable flooding.  A 24-hour 
rainfall total of 8.60 inches (218.4 mm) was recently reported in 
Embalse Herradura, Pinar del Rio, Cuba, by the Meteorological 
Service of Cuba.

Over the Southeastern U.S. into the Southern Appalachians, Helene
is expected to produce total rain accumulations of 5 to 10 inches
with isolated totals around 15 inches. This rainfall will likely
result in areas of considerable flash and urban flooding, with areas
of significant river flooding. Landslides are possible in areas of
steep terrain in the southern Appalachians.

For a complete depiction of forecast rainfall associated with
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.

TORNADOES: A tornado or two may occur tonight over parts of the
Florida Peninsula and southern Alabama. The risk of tornadoes will
increase on Thursday, expanding northward across Florida into parts
of Georgia and South Carolina.

SURF: Swells generated by Helene will affect the southern coast of
Cuba and the Yucatan Peninsula of Mexico during the next couple of
days.  Swells will spread northward toward the west coast of Florida
and the northeastern Gulf Coast later today and Thursday. 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 400 PM CDT.

$$
Forecaster Berg




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