ZCZC MIATCPAT3 ALL
TTAA00 KNHC DDHHMM
Potential Tropical Cyclone Three Intermediate Advisory Number 5A
NWS National Hurricane Center Miami FL AL032021
700 PM CDT Fri Jun 18 2021
...DISTURBANCE APPROACHING THE NORTH-CENTRAL GULF COAST...
...HEAVY RAINFALL AND TROPICAL-STORM-FORCE WINDS CONTINUING TO
SPREAD ACROSS THE REGION...
SUMMARY OF 700 PM CDT...0000 UTC...INFORMATION
ABOUT 100 MI...160 KM S OF MORGAN CITY LOUISIANA
ABOUT 260 MI...420 KM SW OF MOBILE ALABAMA
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...N OR 5 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Warning is in effect for...
* East of Morgan City, Louisiana to the Okaloosa/Walton County line
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within the
next 6-12 hours.
Interests elsewhere along the northern Gulf Coast should monitor
the progress of this system.
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 700 PM CDT (0000 UTC), the disturbance was centered near latitude
28.3 North, longitude 91.1 West. The system is moving toward the
north near 16 mph (26 km/h) and a north to north-northeast motion is
expected during the next day or so. On the forecast track, the
system will make landfall along the north-central Gulf Coast tonight
or early Saturday. A northeastward or east-northeastward motion
across the southeastern United States is forecast after landfall
through the weekend.
Maximum sustained winds are near 45 mph (75 km/h) with higher
gusts. Satellite images and surface observations indicate that the
circulation is slowly becoming better defined, and the system still
is likely to become a tropical or subtropical storm before landfall.
Regardless of its status, little change in strength is expected
through landfall. Weakening is forecast to begin after the system
crosses the coast.
* Formation chance through 48 hours...high ...90 percent.
* Formation chance through 5 days...high...90 percent.
Tropical-storm-force winds extend outward up to 205 miles (335 km)
mainly to the east of the center. An oil rig south of the
southeastern coast of Louisiana recently reported sustained winds of
44 mph (70 km/h) and a wind gust of 58 mph (93 km/h).
The estimated minimum central pressure based on surface
observations and Air Force Hurricane Hunter data is 1007 mb (29.74
HAZARDS AFFECTING LAND
Key messages for Potential Tropical Cyclone Three can be found in
the Tropical Cyclone Discussion under AWIPS header MIATCDAT3,
WMO header WTNT43 KNHC, and on the web at
RAINFALL: The potential tropical cyclone is expected to produce
rainfall totals of 4 to 8 inches with isolated maximum amounts of 12
inches across portions of the Central Gulf Coast. Considerable
flash, urban and small stream flooding impacts as well as new and
renewed minor to isolated moderate river flooding are likely.
As the system continues to lift northeast through the weekend, heavy
rain will expand across southeastern Mississippi, southern and
central Alabama, central to northern Georgia, far western North
Carolina and western South Carolina, resulting in rainfall totals of
3 to 5 inches with isolated maximum amounts of 7 inches. Flash,
urban, small stream and isolated minor river flooding impacts are
STORM SURGE: The combination of 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...
Morgan City, LA to Okaloosa/Walton County Line, FL...2-3 ft
Lake Borgne and Mobile Bay...2-3 ft
Lake Pontchartrain and Lake Maurepas...1-2 ft
Okaloosa/Walton County Line, FL to Panama City, FL...1-2 ft
Pensacola Bay, Choctawhatchee Bay, and Saint Andrew Bay...1-2 ft
Cameron, LA to Morgan City, LA...1-2 ft
Vermilion Bay...1-2 ft
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 are beginning to reach the coast
within the warning area, and these winds will continue into
TORNADOES: There is a threat for a tornado or two tonight
across coastal Louisiana. A few tornadoes are possible on
Saturday across southern portions of Louisiana, Mississippi,
Alabama, and the western Florida Panhandle.
Next complete advisory at 1000 PM CDT.