000 WTNT32 KNHC 172123 TCPAT2 BULLETIN TROPICAL STORM HELENE SPECIAL ADVISORY NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012 430 PM CDT FRI AUG 17 2012 ...AIRCRAFT FINDS TROPICAL STORM HELENE...TROPICAL STORM WARNING ISSUED FOR THE COAST OF MEXICO... SUMMARY OF 430 PM CDT...2130 UTC...INFORMATION ---------------------------------------------- LOCATION...20.6N 96.1W ABOUT 90 MI...140 KM ESE OF TUXPAN MEXICO ABOUT 160 MI...260 KM SE OF TAMPICO MEXICO MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 7 MPH...11 KM/H MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY... THE GOVERNMENT OF MEXICO HAS ISSUED A TROPICAL STORM WARNING FOR THE COAST OF MEXICO FROM BARRA DE NAUTLA TO LA CRUZ. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A TROPICAL STORM WARNING IS IN EFFECT FOR... * THE COAST OF MEXICO FROM BARRA DE NAUTLA TO LA CRUZ A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN THE NEXT 24 HOURS. FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ AT 430 PM CDT...2130 UTC...THE CENTER OF TROPICAL STORM HELENE WAS LOCATED BY AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT NEAR LATITUDE 20.6 NORTH...LONGITUDE 96.1 WEST. HELENE IS MOVING TOWARD THE NORTHWEST NEAR 7 MPH...11 KM/H...AND THIS MOTION IS EXPECTED TO CONTINUE FOR THE NEXT DAY OR TWO. ON THE FORECAST TRACK...THE CENTER OF HELENE WILL MAKE LANDFALL IN THE WARNING AREA ON SATURDAY. DATA FROM THE AIRCRAFT INDICATE THAT MAXIMUM SUSTAINED WINDS ARE NEAR 45 MPH...75 KM/H...WITH HIGHER GUSTS. SOME STRENGTHENING IS POSSIBLE BEFORE THE HELENE MOVES INLAND...WITH WEAKENING EXPECTED AFTER LANDFALL. TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 35 MILES...55 KM FROM THE CENTER. THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY THE AIRCRAFT WAS 1004 MB...29.65 INCHES. HAZARDS AFFECTING LAND ---------------------- WIND...TROPICAL STORM CONDITIONS ARE EXPECTED TO FIRST REACH THE COAST WITHIN THE WARNING AREA LATER TONIGHT. RAINFALL...HELENE IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES..WITH ISOLATED MAXIMUM AMOUNTS OF 15 INCHES ACROSS NORTHEASTERN PORTIONS OF MEXICO FROM NORTHERN VERACRUZ...ACROSS SOUTHERN TAMAULIPAS AND EASTERN SAN LUIS STATES. THESE RAINS MAY PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES ACROSS HIGHER ELEVATIONS. STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 1 TO 2 FEET ABOVE NORMAL TIDE LEVELS ALONG THE IMMEDIATE COAST NEAR AND TO THE NORTH OF WHERE THE CENTER MAKES LANDFALL. NEXT ADVISORY ------------- NEXT INTERMEDIATE ADVISORY...700 PM CDT. NEXT COMPLETE ADVISORY...1000 PM CDT. $$ FORECASTER BRENNAN