000 ABPZ30 KNHC 011813 TWSEP MONTHLY TROPICAL WEATHER SUMMARY NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 800 AM PDT MON OCT 1 2007 FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE.. THREE TROPICAL STORMS FORMED IN THE EASTERN NORTH PACIFIC DURING SEPTEMBER...WITH TWO OF THESE STORMS BECOMING HURRICANES...BUT NONE BECOMING MAJOR HURRICANES. THESE TOTALS ARE CLOSE TO THE LONG-TERM SEPTEMBER AVERAGES OF THREE TROPICAL STORMS...TWO HURRICANES...AND ONE MAJOR HURRICANE. HOWEVER...THE SEPTEMBER ACCUMULATED CYCLONE ENERGY (ACE) INDEX...WHICH MEASURES THE COMBINED STRENGTH AND DURATION OF NAMED STORMS AND HURRICANES...WAS ONLY ABOUT HALF OF THE LONG-TERM AVERAGE...CONTINUING THE TREND OF NEAR-RECORD-LOW ACTIVITY DURING THE EASTERN NORTH PACIFIC HURRICANE SEASON. SO FAR...2007 IS THE SECOND QUIETEST SEASON (BASED ON RELIABLE RECORDS SINCE 1971) BEHIND 1977 IN TERMS OF ACE. ALSO OCCURRING IN SEPTEMBER WERE TROPICAL DEPRESSION GIL...WHICH DISSIPATED EARLY IN THE MONTH...AND TROPICAL DEPRESSION THIRTEEN-E. GIL FORMED IN AUGUST...AND AT THE BEGINNING OF SEPTEMBER IT WAS A TROPICAL DEPRESSION WITH 30 KT MAXIMUM WINDS AND WAS LOCATED ABOUT 575 N MI WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. GIL DEGENERATED INTO A REMNANT LOW OVER COOLER WATERS ON 2 SEPTEMBER ABOUT 800 N MI WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. HENRIETTE FORMED DURING AUGUST...AND AS SEPTEMBER BEGAN IT WAS A TROPICAL STORM WITH MAXIMUM WINDS OF 45 KT LOCATED ABOUT 120 N MI WEST OF ACAPULCO MEXICO. THE STORM STEADILY STRENGTHENED ON 1 SEPTEMBER AND REACHED AN INTENSITY OF 60 KT EARLY THE NEXT DAY...AS IT MOVED WEST-NORTHWESTWARD AND PARALLEL TO THE MEXICAN COAST. HENRIETTE REMAINED JUST SHY OF HURRICANE STRENGTH FOR THE NEXT TWO DAYS AS IT HEADED GENERALLY NORTHWESTWARD AND AWAY FROM THE COAST. EARLY ON 4 SEPTEMBER HENRIETTE FINALLY REACHED HURRICANE STATUS AS IT TURNED NORTH-NORTHWESTWARD TOWARD THE BAJA CALIFORNIA PENINSULA. THE HURRICANE REACHED ITS PEAK INTENSITY OF 75 KT THAT MORNING WHILE CENTERED ABOUT 75 N MI SOUTH-SOUTHEAST OF CABO SAN LUCAS MEXICO. THE CENTER OF HENRIETTE MADE LANDFALL JUST EAST OF CABO SAN LUCAS ON THE AFTERNOON OF 4 SEPTEMBER WITH MAXIMUM WINDS NEAR 70 KT. CONTINUING NORTH-NORTHWESTWARD...HENRIETTE EMERGED OVER THE GULF OF CALIFORNIA EARLY ON 5 SEPTEMBER. THE BRIEF INTERACTION WITH THE BAJA CALIFORNIA PENINSULA CAUSED SLIGHT WEAKENING...BUT HENRIETTE REMAINED A HURRICANE THROUGHOUT MOST OF THAT DAY. IT MADE ITS FINAL LANDFALL ALONG THE COAST OF MAINLAND MEXICO...NEAR GUAYMAS...VERY LATE ON 5 SEPTEMBER. HENRIETTE WEAKENED QUICKLY OVER LAND AND DISSIPATED OVER THE MOUNTAINS OF NORTHWESTERN MEXICO EARLY ON 6 SEPTEMBER. MEDIA REPORTS INDICATE AT LEAST NINE FATALITIES IN MEXICO ARE DIRECTLY ATTRIBUTABLE TO HENRIETTE. SIX OF THESE DEATHS OCCURRED NEAR ACAPULCO DUE TO MUD SLIDES INDUCED BY HEAVY RAINS WHILE THE CENTER OF HENRIETTE PASSED JUST OFFSHORE. TROPICAL DEPRESSION THIRTEEN-E ORIGINATED FROM A TROPICAL WAVE THAT MOVED WESTWARD FROM THE COAST OF AFRICA ON 27 AUGUST AND REACHED THE EASTERN PACIFIC ON 7 SEPTEMBER. THE WAVE MOVED WESTWARD WITH LITTLE DEVELOPMENT UNTIL 18 SEPTEMBER...WHEN THE ASSOCIATED THUNDERSTORM ACTIVITY BECAME BETTER ORGANIZED. A TROPICAL DEPRESSION FORMED ON 19 SEPTEMBER ABOUT 1070 N MI WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. THE CYCLONE MOVED SLOWLY WESTWARD UNTIL IT WEAKENED TO A REMNANT LOW THE NEXT DAY ABOUT 1190 N MI WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. IVO FORMED FROM A TROPICAL WAVE...AND BECAME A DEPRESSION ON 18 SEPTEMBER ABOUT 400 N MI SOUTH-SOUTHWEST OF MANZANILLO MEXICO. THE DEPRESSION BECAME A TROPICAL STORM EARLY THE NEXT DAY AS IT MOVED WEST-NORTHWESTWARD...AND REACHED HURRICANE STRENGTH EARLY ON 20 SEPTEMBER. ROUNDING THE PERIPHERY OF MID-LEVEL HIGH PRESSURE...IVO TURNED NORTHWESTWARD AND THEN NORTHWARD...REACHING ITS PEAK INTENSITY OF 70 KT LATE ON 20 SEPTEMBER...ABOUT 350 N MI SOUTH-SOUTHWEST OF CABO SAN LUCAS. IVO TURNED NORTH-NORTHEASTWARD ON 21 SEPTEMBER AND BEGAN TO WEAKEN UNDER THE INFLUENCE OF WESTERLY SHEAR. IVO WEAKENED TO A TROPICAL STORM AND CONTINUED SLOWLY TOWARD THE NORTH-NORTHEAST FOR THE NEXT COUPLE OF DAYS...BECOMING A TROPICAL DEPRESSION EARLY ON 23 SEPTEMBER ABOUT 90 N MI WEST OF CABO SAN LUCAS. IVO TURNED EASTWARD AND DEGENERATED TO A REMNANT LOW LATER THAT DAY ABOUT 80 N MI SOUTHWEST OF CABO SAN LUCAS. JULIETTE FORMED FROM A TROPICAL WAVE THAT MOVED ACROSS CENTRAL AMERICA ON 22 SEPTEMBER AND INTO THE EASTERN NORTH PACIFIC ON 23 SEPTEMBER. THE WAVE MOVED WESTWARD PRODUCING DISORGANIZED THUNDERSTORMS DURING 24-26 SEPTEMBER. BY 27 SEPTEMBER... THUNDERSTORM ACTIVITY BECAME BETTER ORGANIZED AND A LOW PRESSURE AREA FORMED ABOUT 280 N MI SOUTH-SOUTHWEST OF MANZANILLO MEXICO. THE SYSTEM CONTINUED TO GRADUALLY GAIN ORGANIZATION...AND A TROPICAL DEPRESSION FORMED EARLY ON 29 SEPTEMBER ABOUT 480 N MI SOUTH OF THE SOUTHERN TIP OF BAJA CALIFORNIA. THE DEPRESSION MOVED NORTHWESTWARD AND STRENGTHENED TO A TROPICAL STORM LATER THAT DAY WHILE CENTERED ABOUT 400 N MI SOUTH-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. ALTHOUGH UNDER THE INFLUENCE OF SOUTHERLY VERTICAL SHEAR...JULIETTE SLOWLY STRENGTHENED AND REACHED ITS PEAK INTENSITY OF 50 KT ON 30 SEPTEMBER. CURRENTLY...JULIETTE IS CENTERED ABOUT 310 N MI WEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA WITH MAXIMUM WINDS OF 45 KT. SUMMARY TABLE NAME DATES MAX WIND (KT) DEATHS ------------------------------------------------------- TS GIL 29 AUG-2 SEP 40 H HENRIETTE 30 AUG-6 SEP 75 9 TD THIRTEEN-E 19-20 SEP 30 H IVO 18-23 SEP 70 TS JULIETTE 29 SEP - 45 ------------------------------------------------------- NOTE...DATES BASED ON COORDINATED UNIVERSAL TIME (UTC) * UNKNOWN AT THIS TIME $$ FORECASTER FRANKLIN/BEVEN/BLAKE/RHOME/KNABB/PASCH