000
WTPZ43 KNHC 060853
TCDEP3
 
Tropical Storm Henriette Discussion Number   9
NWS National Hurricane Center Miami FL       EP082025
1100 PM HST Tue Aug 05 2025
 
The satellite presentation of Henriette has changed little since the 
previous advisory, with intermittent bursts of deep convection 
continuing, primarily located over and west of the cyclone’s 
low-level center.  Recent subjective Dvorak intensity estimates from 
TAFB and SAB were 3.0/45 kt and 2.5/35 kt, respectively, while 
objective estimates from UW-CIMSS have ranged between 34 and 46 kt 
over the past several hours.  A timely 06/0525Z Metop-C ASCAT pass 
revealed several 40-45 kt wind barbs north of the low-level center. 
Based on these data, the initial intensity for this advisory remains 
45 kt.

Henriette has recently turned toward the west, or 280 degrees, at 13 
kt. This general motion is expected to persist over the next couple 
of days as the cyclone is steered by a strengthening subtropical 
ridge situated to the north.  By around 72 hours, a gradual turn 
toward the west-northwest or northwest is anticipated as an 
amplifying longwave trough northwest of Hawaii begins to erode the 
western periphery of the ridge.  The official track forecast is 
closely aligned with the latest multi-model consensus aids and 
remains very similar to the previous advisory.

Henriette is forecast to remain in a low vertical wind shear 
environment for the next several days. During this period, sea 
surface temperatures are expected to gradually decrease to near or 
slightly below 24C, while mid-level moisture drops below 50 percent. 
Despite these marginal thermodynamic conditions, Henriette’s broad 
circulation and well-established inner core should allow the system 
to remain relatively resilient in the low shear environment.  Only 
slight weakening is forecast during the next few days, followed by 
little change in strength.  Toward the end of the forecast period, 
sea surface temperatures are expected to rise again.  If the system 
manages to endure the cooler waters, as persistently suggested by 
both the GFS and ECMWF models, some re-intensification is possible.  
The official forecast reflects this potential and lies near the 
middle of the intensity guidance envelope.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/0900Z 17.8N 128.2W   45 KT  50 MPH
 12H  06/1800Z 18.1N 130.4W   45 KT  50 MPH
 24H  07/0600Z 18.4N 133.4W   40 KT  45 MPH
 36H  07/1800Z 18.7N 136.4W   40 KT  45 MPH
 48H  08/0600Z 19.2N 139.4W   40 KT  45 MPH
 60H  08/1800Z 19.9N 142.3W   40 KT  45 MPH
 72H  09/0600Z 20.9N 145.2W   40 KT  45 MPH
 96H  10/0600Z 23.3N 149.9W   40 KT  45 MPH
120H  11/0600Z 26.1N 154.1W   50 KT  60 MPH
 
$$
Forecaster Jelsema (CPHC)