000 WTNT34 KNHC 280559 TCPAT4 BULLETIN TROPICAL STORM ISAAC INTERMEDIATE ADVISORY NUMBER 28A NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012 100 AM CDT TUE AUG 28 2012 ...ISAAC CONTINUES TO HEAD FOR THE NORTHERN GULF COAST...SIGNIFICANT STORM SURGE AND FRESHWATER FLOOD THREAT EXPECTED... SUMMARY OF 100 AM CDT...0600 UTC...INFORMATION ---------------------------------------------- LOCATION...27.4N 87.7W ABOUT 145 MI...235 KM SE OF THE MOUTH OF THE MISSISSIPPI RIVER ABOUT 220 MI...355 KM SSE OF BILOXI MISSISSIPPI MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...978 MB...28.88 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY... NONE. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A HURRICANE WARNING IS IN EFFECT FOR... * EAST OF MORGAN CITY LOUISIANA TO THE ALABAMA-FLORIDA 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 ALABAMA-FLORIDA BORDER TO THE AUCILLA RIVER * INTRACOASTAL CITY TO MORGAN CITY LOUISIANA A TROPICAL STORM WATCH IS IN EFFECT FOR... * EAST OF SABINE PASS TO WEST OF INTRACOASTAL CITY 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...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ AT 100 AM CDT...0600 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE 27.4 NORTH...LONGITUDE 87.7 WEST. ISAAC IS MOVING TOWARD THE NORTHWEST NEAR 12 MPH...19 KM/H. THIS GENERAL MOTION WITH SOME DECREASE IN FORWARD SPEED IS EXPECTED DURING THE NEXT DAY OR TWO. ON THE FORECAST TRACK...THE CENTER OF ISAAC WILL MOVE OVER THE NORTH-CENTRAL GULF OF MEXICO THIS MORNING AND APPROACH THE COAST OF SOUTHEASTERN LOUISIANA AND MISSISSIPPI THIS AFTERNOON OR TONIGHT. MAXIMUM SUSTAINED WINDS ARE NEAR 70 MPH...110 KM/H...WITH HIGHER GUSTS. STRENGTHENING IS FORECAST...AND ISAAC IS EXPECTED TO BECOME A HURRICANE TODAY...AND CONTINUE TO STRENGTHEN UNTIL LANDFALL OCCURS ALONG THE NORTHERN GULF COAST. TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 205 MILES...335 KM FROM THE CENTER. THE MINIMUM CENTRAL PRESSURE REPORTED BY AN AIR FORCE HURRICANE HUNTER AIRCRAFT WAS 978 MB...28.88 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... * SOUTHEAST LOUISIANA AND MISSISSIPPI...6 TO 12 FT * ALABAMA...6 TO 9 FT * SOUTH-CENTRAL LOUISIANA...3 TO 6 FT * FLORIDA PANHANDLE...3 TO 6 FT * FLORIDA WEST COAST INCLUDING APALACHEE BAY...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 EXPECTED TO SPREAD NORTHWARD INTO THE FLORIDA BIG BEND AREA AND THE FLORIDA PANHANDLE IN THE TROPICAL STORM WARNING AREA THIS MORNING. TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH THE NORTHERN GULF COAST IN THE HURRICANE WARNING AREA THIS MORNING...WITH HURRICANE CONDITIONS EXPECTED BY THIS AFTERNOON. RAINFALL...ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL AMOUNTS OF 6 TO 12 INCHES...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 18 INCHES...IN SOUTHEASTERN LOUISIANA...SOUTHERN MISSISSIPPI... SOUTHERN ALABAMA...AND THE EXTREME WESTERN FLORIDA PANHANDLE. TORNADOES...ISOLATED TORNADOES ARE POSSIBLE ACROSS WEST-CENTRAL AND NORTHWESTERN FLORIDA THROUGH THIS MORNING...AND ALONG THE NORTHERN GULF COAST TODAY AND TONIGHT. SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO AFFECT THE FLORIDA COASTLINE AND THE FLORIDA KEYS DURING THE NEXT DAY OR SO...AND ARE BEGINNING TO AFFECT PORTIONS OF THE NORTHERN GULF COAST. NEXT ADVISORY ------------- NEXT COMPLETE ADVISORY...400 AM CDT. $$ FORECASTER PASCH