000
ABPZ30 KNHC 191733
TWSEP 
MONTHLY TROPICAL WEATHER SUMMARY
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1100 AM PDT FRI SEP 19 2008
 
FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE..

OVERALL TROPICAL CYCLONE ACTIVITY DURING AUGUST WAS BELOW AVERAGE.  
THREE TROPICAL STORMS...ONE HURRICANE...AND ONE MAJOR HURRICANE WAS
NOTED.  THIS COMPARES TO THE 1971-2007 AVERAGES OF FOUR TROPICAL
STORMS...TWO HURRICANES...AND ONE MAJOR HURRICANE.  IN TERMS OF THE
ACCUMULATED CYCLONE ENERGY INDEX (ACE)...AUGUST 2008 WAS ABOUT HALF
THE LONG-TERM AVERAGE.  

HERNAN DEVELOPED FROM A TROPICAL WAVE THAT DEPARTED THE WEST COAST
OF AFRICA ON 24 JULY AND ENTERED THE EASTERN NORTH PACIFIC OCEAN ON
2 AUGUST. THE WAVE SPAWNED A BROAD AREA OF LOW PRESSURE ABOUT 600
MILES SOUTH OF MANZANILLO MEXICO ON 5 AUGUST. LATE THE NEXT DAY...
THE LOW BECAME A TROPICAL DEPRESSION ABOUT 700 MILES SOUTH OF THE
SOUTHERN TIP OF BAJA CALIFORNIA. THE DEPRESSION STRENGTHENED INTO A
TROPICAL STORM SIX HOURS LATER. HERNAN INITIALLY MOVED
WEST-NORTHWESTWARD WHILE GRADUALLY STRENGTHENING OVER THE OPEN
WATERS OF THE EASTERN PACIFIC. BY 8 AUGUST...HERNAN TURNED WESTWARD
AND REACHED HURRICANE STRENGTH ABOUT 875 MILES SOUTHWEST OF THE
SOUTHERN TIP OF BAJA CALIFORNIA. OVER THE NEXT DAY OR SO...HERNAN
MOVED WEST-NORTHWESTWARD AND BECAME THE FIRST MAJOR HURRICANE OF
THE 2008 EASTERN PACIFIC SEASON. HERNAN REACHED A PEAK INTENSITY OF
120 MPH AT 1800 UTC 9 AUGUST. SHORTLY THEREAFTER...THE HURRICANE
MOVED OVER COOLER WATERS WHICH INITIATED WEAKENING...AND HERNAN
BECOME A TROPICAL STORM ON THE 11 AUGUST. THE STORM TURNED WESTWARD
TO WEST-SOUTHWESTWARD AND ASSOCIATED THUNDERSTORM ACTIVITY
DIMINISHED THE NEXT DAY. HERNAN DEGENERATED INTO A REMNANT LOW
PRESSURE SYSTEM EARLY ON 13 AUGUST WHILE LOCATED 1650 MILES
WEST-SOUTHWEST OF BAJA CALIFORNIA. THE REMNANT LOW CONTINUED MOVING
WEST-SOUTHWESTWARD AND EVENTUALLY DISSIPATED ABOUT 450 MILES
SOUTHEAST OF THE HAWAIIAN ISLANDS ON 16 AUGUST. THERE ARE NO
REPORTS OF CASUALTIES OR DAMAGE.

ISELLE WAS A RELATIVELY SHORT-LIVED TROPICAL STORM THAT DID NOT POSE
ANY THREAT TO LAND AREAS IN THE NORTHEASTERN PACIFIC OCEAN BASIN.
ISELLE DEVELOPED ON 13 AUGUST ABOUT 210 MILES SOUTH-SOUTHWEST OF
MANZANILLO MEXICO AND BECAME A TROPICAL STORM SIX HOURS LATER.
HOWEVER...STRONG UPPER-LEVEL WINDS INHIBITED STRENGTHENING
THROUGHOUT ISELLE'S LIFETIME...AND THE CYCLONE PEAKED EARLY ON 15
AUGUST WITH 50 MPH WINDS WHEN IT WAS ABOUT 355 MILES SOUTH OF THE
SOUTHERN TIP OF BAJA CALIFORNIA. CONTINUING WESTWARD BENEATH
HOSTILE UPPER-LEVEL EASTERLY SHEAR CONDITIONS...ISELLE WEAKENED TO
A TROPICAL DEPRESSION ON 16 AUGUST...AND DEGENERATED INTO A
NON-CONVECTIVE REMNANT LOW PRESSURE SYSTEM LATER THAT DAY ABOUT 350
MILES SOUTH-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. THE
REMNANT LOW CONTINUED SLOWLY WESTWARD FOR THE NEXT TWO DAYS BEFORE
TURNING SHARPLY SOUTHWESTWARD ON 19 AUGUST. THE LOW DISSIPATED
THREE DAYS LATER ON 22 AUGUST ABOUT 1200 MILES SOUTHWEST OF THE
SOUTHERN TIP OF BAJA CALIFORNIA. THERE ARE NO REPORTS OF CASUALTIES
OR DAMAGE.

JULIO FORMED ABOUT 375 MILES SOUTH-SOUTHEAST OF THE SOUTHERN TIP OF
BAJA CALIFORNIA ON 23 AUGUST.  THE TROPICAL DEPRESSION QUICKLY
INTENSIFIED INTO A TROPICAL STORM AND MOVED NORTHWESTWARD TO
NORTH-NORTHWESTWARD.  JULIO REACHED ITS PEAK INTENSITY OF 50 MPH ON
24 AUGUST AS ITS CENTER NEARED CABO SAN LUCAS MEXICO.  LATER THAT
DAY...THE STORM MADE LANDFALL NEAR CABO SAN LUCAS. JULIO MOVED
ALONG THE SOUTHERN AND CENTRAL BAJA CALIFORNIA PENINSULA OVER THE
NEXT DAY OR SO WHILE VERY SLOWLY LOSING STRENGTH. HOWEVER...THE
CYCLONE PRODUCED LOCALLY HEAVY RAINFALL ACROSS THE BAJA PENINSULA. 
JULIO WEAKENED TO A TROPICAL DEPRESSION EARLY ON 26 AUGUST AND
DISSIPATED OVER THE GULF OF CALIFORNIA LATER THAT DAY.  THERE ARE
NO REPORTS OF CASUALTIES OR SIGNIFICANT DAMAGE.

SUMMARY TABLE

NAME           DATES             MAX WIND (MPH)       DEATHS
-----------------------------------------------------------------
MH HERNAN      6-13 AUG             120                 0
TS ISELLE     13-17 AUG              50                 0
TS JULIO      23-26 AUG              50                 0
-------------------------------------------------------------------

NOTES...DATES BASED ON COORDINATED UNIVERSAL TIME (UTC)
 
$$
FORECASTER BLAKE/BROWN/STEWART