Issued at 1100 AM HST Mon Aug 04 2025
027 
WTPZ43 KNHC 042034
TCDEP3

Tropical Storm Henriette Discussion Number 3
NWS National Hurricane Center Miami FL EP082025
1100 AM HST Mon Aug 04 2025

Conventional satellite imagery shows that the cyclone has become
better organized, during the past several hours. A curved band has
developed over the west side of the cyclone, and deep convection is
developing over the surface center. A 1336 UTC ESA Soil Moisture
Ocean Salinity (SMOS) overpass indicated 34-40 kt winds in the
north quadrant of the cyclone, and a 1746 UTC ASCAT-B pass
revealed 38 kt winds in the same region. ADT/AiDT and ATMS
sounder objective satellite intensity estimates yield 34 kts, while
the subjective Dvorak estimates from TAFB and SAB support 35 kt.
Based on these data, the depression has been upgraded to Tropical
Storm Henriette with the initial intensity set at 40 kt.

The intensity forecast philosophy is unchanged from the previous one
with gradual strengthening expected during the next couple of days.
By mid-period, Henriette should slowly weaken and then level off
with little change in strength as it traverses cooler oceanic
surface temperatures and moves into a drier, more stable surrounding
environment. The NHC intensity forecast has been lowered a bit to
agree more with the Decay-SHIPS, the IVCN intensity consensus model,
and the GFS and ECMWF deterministic models.

The initial motion is estimated to be west-northwestward, or 295/13
kt. The global models indicate that a strong mid- to
upper-tropospheric ridge anchored to the north of the cyclone should
continue to steer Henriette in this general direction through 96
hours. Around day 5, a gradual turn toward the northwest is
expected in response to a mid-latitude mid-level trough moving
toward the Hawaiian Islands from the north-central Pacific.


FORECAST POSITIONS AND MAX WINDS

INIT 04/2100Z 14.8N 120.6W 40 KT 45 MPH
12H 05/0600Z 15.5N 122.4W 45 KT 50 MPH
24H 05/1800Z 16.3N 124.9W 50 KT 60 MPH
36H 06/0600Z 17.1N 127.6W 50 KT 60 MPH
48H 06/1800Z 17.6N 130.4W 50 KT 60 MPH
60H 07/0600Z 18.1N 133.4W 45 KT 50 MPH
72H 07/1800Z 18.4N 136.5W 45 KT 50 MPH
96H 08/1800Z 19.5N 142.2W 40 KT 45 MPH
120H 09/1800Z 21.5N 147.4W 40 KT 45 MPH

$$
Forecaster Roberts


Source: Tropical Storm Henriette Forecast Discussion Number 3