000
WTPZ43 KNHC 080843
TCDEP3
 
HURRICANE HENRIETTE DISCUSSION NUMBER  20
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP082013
200 AM PDT THU AUG 08 2013
 
AN EYE HAS BEEN OBSERVED IN INFRARED IMAGERY DURING THE PAST SEVERAL
HOURS...ALTHOUGH THE CONVECTIVE CANOPY OF HENRIETTE IS SHRINKING. 
THE WIND FIELD HAS ALSO SHRUNK BASED ON RECENT ASCAT DATA.  DVORAK
CURRENT INTENSITY ESTIMATES ARE T4.5 FROM TAFB AND SAB...AND T4.2
FROM THE UW-CIMSS ADT...SO THE WINDS ARE BEING HELD AT 75 KT FOR
THIS ADVISORY.  HOWEVER...WEAKENING APPEARS IMMINENT NOW THAT
HENRIETTE IS MOVING OVER WATER THAT IS COLDER THAN 26C AND IS
EXPERIENCING 10-15 KT OF SHEAR FROM THE WEST-SOUTHWEST.  THE
OFFICIAL FORECAST CONTINUES TO SHOW WEAKENING AND IS MOSTLY
UNCHANGED FROM THE PREVIOUS FORECAST DURING THE FIRST 3 DAYS. 
AFTER THAT...HENRIETTE IS EXPECTED TO BECOME A REMNANT LOW BY DAY 4
AND DISSIPATE BY DAY 5 WELL SOUTH OF HAWAII AS SHOWN BY THE GLOBAL
MODELS.
 
HENRIETTE IS GRADUALLY TURNING LEFT AND HAS SLOWED DOWN A BIT WITH
AN INITIAL MOTION OF 290/8 KT.  A NARROW MID-LEVEL RIDGE IS
FORECAST TO TURN THE HURRICANE WESTWARD WITHIN 12 HOURS OR SO.
THEN...AS THE CYCLONE WEAKENS...LOWER-LEVEL FLOW IS EXPECTED TO
INDUCE A WEST-SOUTHWESTWARD MOTION BY 36 HOURS.  THE TRACK GUIDANCE
IS IN RELATIVELY GOOD AGREEMENT THROUGHOUT THE FORECAST PERIOD...AND
THE NEW NHC FORECAST IS VERY CLOSE TO THE PREVIOUS FORECAST AND THE
MULTI-MODEL CONSENSUS TVCE.
 
ON THE CURRENT FORECAST...HENRIETTE SHOULD CROSS 140W INTO THE
CENTRAL PACIFIC HURRICANE CENTER AREA OF RESPONSIBILITY IN ABOUT 24
HOURS OR SO.

FORECAST POSITIONS AND MAX WINDS
 
INIT  08/0900Z 17.2N 137.4W   75 KT  85 MPH
 12H  08/1800Z 17.4N 138.7W   70 KT  80 MPH
 24H  09/0600Z 17.3N 140.5W   60 KT  70 MPH
 36H  09/1800Z 16.8N 142.6W   55 KT  65 MPH
 48H  10/0600Z 16.2N 145.0W   45 KT  50 MPH
 72H  11/0600Z 15.3N 150.7W   35 KT  40 MPH
 96H  12/0600Z 14.0N 157.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  13/0600Z...DISSIPATED
 
$$
FORECASTER BERG