000 WTNT34 KNHC 281458 TCPAT4 BULLETIN TROPICAL STORM ISAAC ADVISORY NUMBER 30 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012 1000 AM CDT TUE AUG 28 2012 ...ISAAC STILL JUST BELOW HURRICANE STRENGTH AS IT CONTINUES NORTHWESTWARD... SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...28.1N 88.5W ABOUT 80 MI...125 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER ABOUT 165 MI...260 KM SE OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...976 MB...28.82 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY... THE HURRICANE WARNING HAS BEEN REPLACED WITH A TROPICAL STORM WARNING FROM THE MISSISSIPPI-ALABAMA BORDER EASTWARD TO DESTIN FLORIDA. THE TROPICAL STORM WARNING HAS BEEN DISCONTINUED EAST OF DESTIN. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A HURRICANE WARNING IS IN EFFECT FOR... * EAST OF MORGAN CITY LOUISIANA TO THE MISSISSIPPI-ALABAMA BORDER... INCLUDING METROPOLITAN NEW ORLEANS...LAKE PONTCHARTRAIN...AND LAKE MAUREPAS A HURRICANE WATCH IS IN EFFECT FOR... * INTRACOASTAL CITY TO MORGAN CITY LOUISIANA A TROPICAL STORM WARNING IS IN EFFECT FOR... * THE MISSISSIPPI-ALABAMA BORDER TO DESTIN FLORIDA * MORGAN CITY TO CAMERON LOUISIANA A TROPICAL STORM WATCH IS IN EFFECT FOR... * EAST OF HIGH ISLAND TEXAS TO JUST WEST OF CAMERON LOUISIANA 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 HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA. A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA. A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH 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 48-HOUR OUTLOOK ------------------------------ AT 1000 AM CDT...1500 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE 28.1 NORTH...LONGITUDE 88.5 WEST. ISAAC IS MOVING TOWARD THE NORTHWEST NEAR 10 MPH...17 KM/H. A NORTHWESTWARD MOTION AT A SLIGHTLY SLOWER SPEED IS EXPECTED OVER THE NEXT DAY OR TWO. ON THE FORECAST TRACK...THE CENTER OF ISAAC SHOULD REACH THE COASTLINE OF SOUTHEASTERN LOUISIANA AS EARLY AS THIS EVENING. MAXIMUM SUSTAINED WINDS ARE NEAR 70 MPH...110 KM/H...WITH HIGHER GUSTS. ISAAC IS EXPECTED TO BECOME A HURRICANE BEFORE MAKING LANDFALL...AND BEGIN TO SLOWLY WEAKEN AFTER THAT. TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 185 MILES...295 KM FROM THE CENTER. THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY HURRICANE HUNTER AIRCRAFT WAS 976 MB...28.82 INCHES. HAZARDS AFFECTING LAND ---------------------- STORM SURGE...THE COMBINATION OF A STORM SURGE AND THE TIDE WILL CAUSE NORMALLY DRY AREAS NEAR THE COAST TO BE FLOODED BY RISING WATERS. THE WATER COULD REACH THE FOLLOWING DEPTHS ABOVE GROUND IF THE PEAK SURGE OCCURS AT THE TIME OF HIGH TIDE... * MISSISSIPPI AND SOUTHEASTERN LOUISIANA...6 TO 12 FT * ALABAMA...4 TO 8 FT * SOUTH-CENTRAL LOUISIANA...3 TO 6 FT * FLORIDA PANHANDLE...3 TO 6 FT * APALACHEE BAY...2 TO 4 FT * REMAINDER OF FLORIDA WEST COAST...1 TO 3 FT THE DEEPEST WATER WILL OCCUR ALONG THE IMMEDIATE COAST IN AREAS OF ONSHORE WINDS. 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 WEATHER SERVICE OFFICE. NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS WAVES. WIND...TROPICAL STORM CONDITIONS ARE BEGINNING TO OCCUR NEAR THE MOUTH OF THE MISSISSIPPI RIVER...AND WILL REACH OTHER PORTIONS OF THE COASTLINE WITHIN THE TROPICAL STORM AND HURRICANE WARNING AREAS BY LATE THIS AFTERNOON. HURRICANE CONDITIONS ARE EXPECTED TO REACH THE COAST BY LATE AFTERNOON. RAINFALL...ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL AMOUNTS OF 7 TO 14 INCHES...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 20 INCHES...IN SOUTHEASTERN LOUISIANA...SOUTHERN MISSISSIPPI... SOUTHERN ALABAMA...AND THE EXTREME WESTERN FLORIDA PANHANDLE. THESE RAINS COULD RESULT IN SIGNIFICANT LOWLAND FLOODING. TORNADOES...TORNADOES MAY OCCUR ALONG THE NORTHERN GULF COAST TODAY. SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO AFFECT THE FLORIDA COASTLINE AND PORTIONS OF THE NORTHERN GULF COAST FOR THE NEXT DAY OR SO. NEXT ADVISORY ------------- NEXT INTERMEDIATE ADVISORY...100 PM CDT. NEXT COMPLETE ADVISORY...400 PM CDT. $$ FORECASTER STEWART