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BULLETIN
Hurricane Sally Special Advisory Number  20
NWS National Hurricane Center Miami FL       AL192020
130 AM CDT Wed Sep 16 2020
 
...SALLY CONTINUES TO STRENGTHEN AS HURRICANE CONDITIONS SPREAD 
ONSHORE THE GULF COAST FROM PENSACOLA BEACH FLORIDA WESTWARD TO 
DAUPHIN ISLAND ALABAMA...
...HISTORIC LIFE-THREATENING FLOODING LIKELY ALONG PORTIONS
OF THE NORTHERN GULF COAST...
 
 
SUMMARY OF 130 AM CDT...0630 UTC...INFORMATION
----------------------------------------------
LOCATION...29.9N 87.8W
ABOUT 60 MI...95 KM SSE OF MOBILE ALABAMA
ABOUT 55 MI...90 KM SW OF PENSACOLA FLORIDA
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...NNE OR 30 DEGREES AT 2 MPH...4 KM/H
MINIMUM CENTRAL PRESSURE...968 MB...28.59 INCHES
 
 
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
 
A Storm Surge Warning has been discontinued from the Mouth of the
Mississippi River to the Mouth of the Pearl River.
 
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
 
A Storm Surge Warning is in effect for...
* Mississippi/Alabama border to the Walton/Bay County Line Florida
* Mobile Bay
 
A Hurricane Warning is in effect for...
* East of Bay St. Louis Mississippi to the Okaloosa/Walton County
line Florida
 
A Tropical Storm Warning is in effect for...
* East of the Okaloosa/Walton County line Florida to Indian Pass
Florida
* Bay St. Louis Mississippi westward to Grand Isle Louisiana
 
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.  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 36 hours.
 
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 130 AM CDT (0630 UTC), the center of Hurricane Sally was located
an Air Force Reserve Hurricane Hunter aircraft and NOAA Doppler
weather radars near latitude 29.9 North, longitude 87.8 West. Sally
is moving toward the north-northeast near 2 mph (4 km/h).  A
north-northeastward to northeastward motion at a slightly faster
forward speed is expected later today and tonight, followed by a
faster northeastward motion on Thursday.  On the forecast track, the
center of Sally will approach the northern Gulf Coast this morning, 
and make landfall in the hurricane warning area later today.  
Sally is then expected to move inland across southeastern Alabama 
tonight.
 
Recent data from An Air Force Reserve reconnaissance aircraft and 
the Mobile Alabama Doppler weather radar indicate that Maximum 
sustained winds have increased to near 105 mph (165 km/h) with 
higher gusts.  Some further strengthening is possible before Sally 
makes landfall. Rapid weakening is expected after landfall occurs.
 
Hurricane-force winds extend outward up to 40 miles (65 km) from the 
center and tropical-storm-force winds extend outward up to 125 miles 
(205 km). A sustained wind of 81 mph (130 km/h) with a gust to 110 
mph (178 km/h) was recently reported in Sally's northern eyewall by 
NOAA buoy 42012, located about 50 miles southeast of Mobile, 
Alabama. A sustained wind of 72 mph (117 km/h) and a gust to 90 mph 
(144 km/h) were recently measured by the NOAA C-MAN observing 
station on Dauphin Island, Alabama.
 
The minimum central pressure recently reported by the Hurricane 
Hunters was 968 mb (28.58 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:  Sally is forecast to produce 10 to 20 inches of rainfall
with isolated amounts of 30 inches along and just inland of the
central Gulf Coast from the Florida Panhandle west of the
Apalachicola River to the Alabama/Mississippi border.  Historic,
life-threatening flash flooding is likely.  In addition, this
rainfall will lead to widespread moderate to major flooding on
area rivers.
 
Sally is forecast to turn inland today and track across the
Southeast producing rainfall of 4 to 8 inches, with isolated maximum
amounts of 12 inches, across portions of southeastern Mississippi,
southern and central Alabama, central and northern Georgia, and the
western Carolinas.  Significant flash and urban flooding is likely,
as well as widespread minor to moderate flooding on some rivers.
 
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...
 
Dauphin Island AL to Okaloosa/Walton County FL Line...4-7 ft
Pensacola Bay and Choctawhatchee Bay FL...4-7 ft
Mobile Bay...3-5 ft
Okaloosa/Walton County Line to Walton/Bay County line FL...2-4 ft
Mouth of the Mississippi River to MS/AL Border including
Lakes Pontchartrain, Maurepas and Borgne...1-3 ft
MS/AL Border to Dauphin Island AL...2-4 ft
Walton/Bay County line 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:  Hurricane conditions are spreading onshore within the
hurricane warning area in Florida and Alabama.  Tropical storm
conditions will continue in portions of the warning areas through
tonight.
 
TORNADOES:  A few tornadoes may occur through today across portions
of the Florida Panhandle and southern Alabama.
 
SURF:  Swells from Sally will continue to affect the coast from the
Florida Big Bend westward to southeastern Louisiana 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 100 AM CDT.
Next complete advisory at 400 AM CDT.
 
$$
Forecaster Stewart
 
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