000 WTNT33 KNHC 180540 TCPAT3  BULLETIN Potential Tropical Cyclone Three Intermediate Advisory Number 2A NWS National Hurricane Center Miami FL       AL032021 100 AM CDT Fri Jun 18 2021  ...POTENTIAL TROPICAL CYCLONE THREE FORECAST TO BRING HEAVY  RAINFALL AND FLOODING TO THE NORTHERN GULF COAST...   SUMMARY OF 100 AM CDT...0600 UTC...INFORMATION ---------------------------------------------- LOCATION...24.0N 92.0W ABOUT 390 MI...630 KM S OF MORGAN CITY LOUISIANA MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES   WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY:  None.  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, in this case within 12  to 24 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 100 AM CDT (0600 UTC), the poorly defined disturbance was  centered near latitude 24.0 North, longitude 92.0 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.  Satellite-derived wind data indicate that the maximum sustained  winds are near 35 mph (55 km/h) with higher gusts. Some  strengthening is forecast, and a subtropical or tropical storm is  likely to form over the west-central or northwestern Gulf of Mexico  later today.  * Formation chance through 48 hours...high...90 percent. * Formation chance through 5 days...high...90 percent.   The estimated minimum central pressure is 1007 mb (29.74 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 today and continuing through the weekend from along 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 later today, making outside preparations difficult or dangerous.  TORNADOES: The threat for a couple of tornadoes is expected to begin this afternoon across coastal Louisiana. This threat should expand northward across southern portions of Louisiana and Mississippi, and southwest Alabama Friday night into Saturday.   NEXT ADVISORY ------------- Next complete advisory at 400 AM CDT.  $$ Forecaster Blake