000 WTNT32 KNHC 172348 TCPAT2 BULLETIN TROPICAL STORM HELENE INTERMEDIATE ADVISORY NUMBER 9A NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012 700 PM CDT FRI AUG 17 2012 ...TROPICAL STORM HELENE DRIFTING NORTHWARD IN THE SOUTHWESTERN GULF OF MEXICO...WITH LITTLE CHANGE IN STRENGTH... SUMMARY OF 700 PM CDT...0000 UTC...INFORMATION ---------------------------------------------- LOCATION...20.7N 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...N OR 360 DEGREES AT 2 MPH...3 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY... NONE. 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 700 PM CDT...0000 UTC..THE CENTER OF TROPICAL STORM HELENE WAS LOCATED BY AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT NEAR LATITUDE 20.7 NORTH...LONGITUDE 96.1 WEST. HELENE HAS BEEN DRIFTING NORTHWARD DURING THE PAST COUPLE OF HOURS...BUT IS EXPECTED TO RESUME A TRACK TOWARD THE NORTHWEST NEAR 7 MPH...11 KM/H LATER TONIGHT. THIS MOTION IS EXPECTED TO CONTINUE FOR THE NEXT DAY OR TWO...AND ON THE FORECAST TRACK...THE CENTER OF HELENE WILL MAKE LANDFALL WITHIN THE WARNING AREA ON SATURDAY. DATA FROM THE AIRCRAFT INDICATE HELENE HAS NOT CONTINUED TO INTENSIFY...AND THE MAXIMUM SUSTAINED WINDS REMAIN NEAR 45 MPH...75 KM/H...WITH HIGHER GUSTS. SOME STRENGTHENING IS POSSIBLE BEFORE 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 1006 MB...29.71 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 COMPLETE ADVISORY...1000 PM CDT. $$ FORECASTER AVILA