955
WTPZ43 KNHC 070846
TCDEP3
TROPICAL STORM HENRIETTE DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082025
1100 PM HST WED AUG 06 2025
SATELLITE IMAGES INDICATE THAT A SMALL BURST OF DEEP CONVECTION HAS
DEVELOPED JUST TO THE NORTHWEST OF HENRIETTE’S LOW-LEVEL CENTER THIS
EVENING, AFTER SEVERAL HOURS WITH NOT MUCH MORE THAN A SHALLOW CLOUD
SWIRL. THE MOST RECENT SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATE
FROM TAFB WAS 3.0/45 KT, WHILE THE OBJECTIVE ESTIMATES FROM UW-CIMSS
RANGED BETWEEN 32 TO 42 KT OVER THE PAST SEVERAL HOURS. A TIMELY
07/0645Z METOP-C ASCAT PASS DEPICTED SEVERAL 40 KT WIND BARBS, WITH
A SINGLE 40–45 KT WIND BARB NOTED NORTH OF THE LOW-LEVEL CENTER.
THE INITIAL INTENSITY FOR THIS ADVISORY WILL BE HELD AT 45 KT,
UTILIZING THE ASCAT DATA WHILE ACCOUNTING FOR SOME UNDERSAMPLING AND
A KNOWN LOW BIAS AT HIGHER SPEEDS.
THE CYCLONE IS MOVING WESTWARD, OR 275 DEGREES, AT 14 KT. THIS
GENERAL MOTION IS EXPECTED TO PERSIST THROUGH THURSDAY, AS HENRIETTE
CONTINUES TO BE STEERED BY A STRENGTHENING SUBTROPICAL RIDGE TO ITS
NORTH. A GRADUAL TURN TOWARD THE WEST-NORTHWEST AND EVENTUALLY
NORTHWEST IS ANTICIPATED FRIDAY AND OVER THE WEEKEND, AS AN
AMPLIFYING LONGWAVE TROUGH NORTHWEST OF HAWAII BEGINS TO ERODE THE
WESTERN EXTENT OF THE SUBTROPICAL RIDGE. THE NORTHWESTWARD MOTION IS
EXPECTED TO CONTINUE INTO EARLY NEXT WEEK. THE OFFICIAL TRACK
FORECAST REMAINS CLOSELY ALIGNED WITH THE LATEST MULTI-MODEL
CONSENSUS AIDS AND IS NEARLY IDENTICAL TO THE PREVIOUS ADVISORY.
HENRIETTE WILL BE MOVING OVER GRADUALLY COOLING SEA SURFACE
TEMPERATURES NEAR 24C, WHILE THE ENVIRONMENTAL HUMIDITIES
SURROUNDING THE CYCLONE WILL DROP BELOW 50 PERCENT. DESPITE THESE
HOSTILE THERMODYNAMIC CONDITIONS, HENRIETTE’S WELL-ESTABLISHED
CIRCULATION IS LIKELY TO REMAIN RESILIENT DUE TO THE LOW-SHEAR
ENVIRONMENT THE CYCLONE WILL BE TRANSITING THROUGH. AS A RESULT,
ONLY A SLIGHT WEAKENING IS FORECAST TONIGHT, FOLLOWED BY LITTLE
CHANGE IN STRENGTH DURING THE NEXT FEW DAYS. IF HENRIETTE CAN
SURVIVE THE PASSAGE OVER THE COOL WATERS, AS PERSISTENTLY SUGGESTED
BY THE GFS AND ECMWF MODELS FOR SEVERAL DAYS NOW, RE-INTENSIFICATION
APPEARS LIKELY OVER THE WEEKEND AND INTO EARLY NEXT WEEK AS SEA
SURFACE TEMPERATURES WARM TO LEVELS CONDUCIVE FOR STRENGTHENING.
THE OFFICIAL FORECAST CONTINUES TO REFLECT THIS, BRINGING HENRIETTE
TO HURRICANE STRENGTH BY 120 HOURS. THE INTENSITY FORECAST IS
MOSTLY UNCHANGED AND REMAINS ALIGNED BEST WITH THE DYNAMICAL
INTENSITY CONSENSUS AID HCCA AND THE REGIONAL HURRICANE MODELS.
FORECAST POSITIONS AND MAX WINDS
INIT 07/0900Z 18.4N 133.9W 40 KT 45 MPH
12H 07/1800Z 18.6N 136.2W 40 KT 45 MPH
24H 08/0600Z 19.1N 139.3W 40 KT 45 MPH
36H 08/1800Z 19.8N 142.3W 40 KT 45 MPH
48H 09/0600Z 20.7N 145.1W 40 KT 45 MPH
60H 09/1800Z 21.9N 147.7W 40 KT 45 MPH
72H 10/0600Z 23.3N 150.1W 45 KT 50 MPH
96H 11/0600Z 26.9N 154.8W 55 KT 65 MPH
120H 12/0600Z 30.2N 158.9W 65 KT 75 MPH
FORECASTER JELSEMA (CPHC)
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