BULLETIN
Tropical Storm Sally Intermediate Advisory Number 22A
NWS National Hurricane Center Miami FL AL192020
100 PM CDT Wed Sep 16 2020
…CATASTROPHIC AND LIFE-THREATENING FLOODING OCCURRING OVER
PORTIONS OF THE FLORIDA PANHANDLE AND SOUTHERN ALABAMA…
SUMMARY OF 100 PM CDT…1800 UTC…INFORMATION
———————————————-
LOCATION…30.9N 87.1W
ABOUT 30 MI…45 KM NNE OF PENSACOLA FLORIDA
MAXIMUM SUSTAINED WINDS…70 MPH…110 KM/H
PRESENT MOVEMENT…NNE OR 30 DEGREES AT 5 MPH…7 KM/H
MINIMUM CENTRAL PRESSURE…982 MB…29.00 INCHES
WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY:
The Hurricane Warning from the Mississippi/Alabama border to the
Okaloosa/Walton County line has been changed to a Tropical Storm
Warning.
The Storm Surge Warning from Dauphin Island, Alabama, to the
Alabama/Florida border has been discontinued.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for…
* Alabama/Florida border to the Walton/Bay County Line Florida
A Tropical Storm Warning is in effect for…
* Mississippi/Alabama border eastward to Indian Pass Florida
A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline 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.
A Tropical Storm Warning means that tropical storm conditions are
occurring within the warning area.
For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.
DISCUSSION AND OUTLOOK
———————-
At 100 PM CDT (1800 UTC), the center of Tropical Storm Sally was
located by NWS Doppler radar and surface observations near latitude
30.9 North, longitude 87.1 West. Sally is moving toward the north-
northeast near 5 mph (7 km/h), and a north-northeastward to
northeastward motion at a slightly faster forward speed is expected
this afternoon and tonight. A faster northeastward motion is
forecast Thursday and Thursday night. On the forecast track, the
center of Sally will move across the extreme western Florida
panhandle and southeastern Alabama through early Thursday, move
over central Georgia on Thursday, and move over South Carolina
Thursday night.
Maximum sustained winds have decreased to near 70 mph (110 km/h)
with higher gusts. Additional weakening is expected as the center
moves farther inland this afternoon and tonight, and Sally is
forecast to become a tropical depression by Thursday morning.
Tropical-storm-force winds extend outward up to 125 miles (205 km)
from the center. A sustained wind of 49 mph (80 km/h) and a gust
of 76 mph (122 km/h) was recently reported at an unofficial
observing site at Tate High School, near Pensacola, Florida. A
sustained wind of 47 mph (76 km/h) and a gust to 60 mph (96 km/h)
was recently observed at the Okaloosa Fishing Pier, near Okaloosa
Island, Florida.
The estimated minimum central pressure is 982 mb (29.00 inches).
HAZARDS AFFECTING LAND
———————-
Key messages for Sally can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC,
and on the web at www.hurricanes.gov/text/MIATCDAT4.shtml
RAINFALL: Through this afternoon, Sally will produce additional
rainfall totals of 8 to 12 inches with localized higher amounts
possible along and just inland of the central Gulf Coast from west
of Tallahassee, Florida to Mobile Bay, Alabama. Storm totals of 10
to 20 inches to isolated amounts of 35 inches are expected. Historic
and catastrophic flooding, including widespread moderate to major
river flooding, is unfolding.
Sally will track across the Southeast through Friday, producing the
following rainfall totals:
Central Alabama to central Georgia: 4 to 8 inches, with isolated
amounts of 12 inches. Significant flash and urban flooding is
likely, as well as widespread minor to moderate flooding on some
rivers.
Western South Carolina into western and central North Carolina: 4 to
6 inches, with isolated amounts of 9 inches. Widespread flash and
urban flooding is possible, as well as minor to moderate river
flooding.
Southeast Virginia: 2 to 5 inches, with isolated amounts of 7
inches. Scattered flash and urban flooding is possible, as well as
scattered minor river flooding.
STORM SURGE: The combination of a dangerous 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…
AL/FL Border to Okaloosa/Walton County Line, FL including Pensacola
Bay and Choctawhatchee Bay…3-5 ft
Okaloosa/Walton County Line, FL to Walton/Bay County Line, FL…2-4
ft
Walton/Bay County Line, FL to Chassahowitzka, FL including Saint
Andrew Bay…1-3 ft
The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
damaging 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.
WIND: Tropical storm conditions will continue in portions of the
warning areas through tonight.
TORNADOES: A few tornadoes may occur today and tonight across
portions of the Florida Panhandle, southeast Alabama, and southwest
Georgia.
SURF: Swells from Sally will continue to affect the Gulf Coast
from the Florida Big Bend westward to southeastern Louisiana during
the next day or so. These swells are likely to cause life-
threatening surf and rip current conditions. Please consult
products from your local weather office.