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Tropical Storm OLAF (Text)

ZCZC MIATCDEP3 ALL
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TROPICAL STORM OLAF DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP182009
800 AM PDT FRI OCT 02 2009
 
SHORTWAVE INFRARED IMAGERY AND A 1008 UTC AQUA-1/AMSR-E MICROWAVE
OVERPASS FROM THE NRL TC WEBSITE INDICATE THAT OLAF IS BECOMING
MORE VERTICALLY TILTED TOWARD THE NORTH DUE TO INCREASING
SOUTH-SOUTHWESTERLY SHEAR. THE STRONGEST CONVECTION AND SURFACE
WINDS ARE CONFINED TO THE NORTH AND EAST SEMICIRCLES.  SHIP
3FXY2...LOCATED ABOUT 110 MILES NORTH-NORTHEAST OF THE CENTER...
REPORTED A 37-KT EAST-NORTHEAST WIND AT 1200 UTC.  BASED ON THE
SHIP REPORT AND A BLEND OF THE DVORAK SATELLITE INTENSITY ESTIMATES
...THE INITIAL INTENSITY WILL REMAIN AT 40 KT FOR THIS ADVISORY. A
GRADUAL WEAKENING IS EXPECTED TO COMMENCE DURING THE NEXT 24 HOURS
AS THE SHEAR IS FORECAST TO INCREASE...AND OLAF SHOULD BEGIN TO
MOVE OVER COOLER SEA SURFACE TEMPERATURES. THE INTENSITY FORECAST
FOLLOWS THIS REASONING AND IS BASED ON THE SHIPS AND LGEM...SHOWING
DISSIPATION OF THE SYSTEM OVER BAJA CALIFORNIA IN 2 DAYS.

BASED ON THE AFOREMENTIONED AMSR-E MICROWAVE PASS AND AN EARLIER
SSMIS IMAGE...THE INITIAL MOTION ESTIMATE IS 360/09. THE CYCLONE IS
EMBEDDED IN LOW- TO MID-TROPOSPHERIC SOUTHERLY FLOW PRODUCED BY A
RIDGE EXTENDING WESTWARD FROM MEXICO. OLAF SHOULD MOVE IN A GENERAL
NORTH TO NORTH-NORTHEAST DIRECTION OVER THE NEXT 24 HOURS.
AFTERWARD...A TURN TO THE NORTHEAST IS EXPECTED IN RESPONSE TO A
MID-LEVEL SHORTWAVE TROUGH THAT MOVES TOWARD SOUTHWEST COAST OF THE
U.S. AND NORTHERN BAJA CALIFORNIA. THIS CHANGE IN THE STEERING
PATTERN SHOULD BRING THE REMNANTS OF OLAF OVER THE CENTRAL WEST
COAST OF BAJA CALIFORNIA IN ABOUT 2 DAYS. THE OFFICIAL TRACK
FORECAST IS BASED ON A COMPROMISE OF THE PREVIOUS ADVISORY AND THE
DYNAMICAL MODEL CONSENSUS...AND IS AGAIN SHIFTED SLIGHTLY TO THE
RIGHT OF THE PREVIOUS PACKAGE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/1500Z 23.1N 117.5W    40 KT
 12HR VT     03/0000Z 24.0N 117.4W    40 KT
 24HR VT     03/1200Z 25.2N 116.8W    35 KT
 36HR VT     04/0000Z 26.2N 115.4W    30 KT
 48HR VT     04/1200Z 27.1N 113.4W    20 KT...REMNANT LOW
 72HR VT     05/1200Z...DISSIPATED
 
$$
FORECASTER ROBERTS/BRENNAN
 
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