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Potential Tropical Cyclone Three Advisory Number 1
NWS National Hurricane Center Miami FL AL032021
400 PM CDT Thu Jun 17 2021
...POTENTIAL TROPICAL CYCLONE OVER THE SOUTHWESTERN GULF OF
...EXPECTED TO BRING HEAVY RAINFALL AND FLOODING TO THE NORTHERN
SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
ABOUT 475 MI...765 KM S OF MORGAN CITY LOUISIANA
MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
A Tropical Storm Warning has been issued for the Gulf Coast from
Intracoastal City, Louisiana, to the Alabama/Florida border,
including Lake Pontchartrain, Lake Maurepas, and Metropolitan New
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Warning is in effect for...
* Intracoastal City Louisiana to the Alabama/Florida border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.
Interests elsewhere along the northern Gulf Coast should monitor
the progress of this system.
DISCUSSION AND OUTLOOK
At 400 PM CDT (2100 UTC), the disturbance was centered near latitude
22.9 North, longitude 92.4 West. The system is moving toward the
north near 9 mph (15 km/h) and this motion with some increase in
forward speed is expected for the next day or so. On the
forecast track, the system will approach the north-central
Gulf Coast late Friday or early Saturday. A northeastward motion
across the southeastern United States is likely after landfall.
Maximum sustained winds are near 30 mph (45 km/h) with higher gusts.
Some strengthening is forecast tonight and Friday.
A subtropical or tropical depression or storm is likely to form
over the west-central Gulf of Mexico tonight or early Friday.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.
The estimated minimum central pressure is 1008 mb (29.77 inches).
HAZARDS AFFECTING LAND
Key messages for Potential Tropical Cyclone Three can be found in
the Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and
WMO header WTNT43 KNHC.
RAINFALL: The potential tropical cyclone is expected to produce
total rainfall of 3 to 6 inches with isolated amounts of 8
inches across the Yucatan Peninsula of Mexico. Rainfall totals of
4 to 8 inches with isolated maximum amounts of 12 inches are
possible beginning Friday and continuing through the weekend from
the Central Gulf coast northeastward into the Southern Appalachians.
This will likely produce areas of flash, urban, and small stream
flooding as well as minor to isolated moderate river flooding with
new and renewed rises on already elevated rivers.
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...
Intracoastal City, LA to MS/AL Border...2-3 ft
Vermilion Bay and Lake Borgne...2-3 ft
Lake Pontchartrain and Lake Maurepas...1-2 ft
MS/AL border to AL/FL border including Mobile Bay...1-3 ft
Cameron, LA to Intracoastal City, LA...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 expected to first reach the
coast within the warning area on Friday, making outside
preparations difficult or dangerous.
TORNADOES: The threat for a couple tornadoes should begin Friday
afternoon across coastal Louisiana. This threat should expand
northward across southern portions of Louisiana and Mississippi, and
southwest Alabama on Saturday.
Next intermediate advisory at 700 PM CDT.
Next complete advisory at 1000 PM CDT.