ZCZC HFOTCDCP3 ALL
TTAA00 PHFO DDHHMM
 
Post-Tropical Cyclone Henriette Discussion Number  19
NWS Central Pacific Hurricane Center Honolulu HI   EP082025
Issued by NWS National Hurricane Center Miami FL
1100 AM HST Fri Aug 08 2025

Approximately 18 hours have passed since Henriette last produced any
significant areas of deep convection, and the cyclone has now been
downgraded to a post-tropical remnant low.  The current motion is
now west-northwestward, or 285/15 kt.  There are no changes to the
track forecast philosophy.  Henriette will move west-northwestward
along the southwestern periphery of a subtropical ridge to its
northeast.  A turn toward the northwest is forecast late this
weekend into early next week as Henriette becomes steered between an
amplifying longwave trough northwest of Hawaii and the subtropical
ridge to its northeast.  No significant changes were made to the NHC
track forecast, which is near the middle of the guidance envelope.
Confidence remains high that Henriette will remain far to the north
of Hawaii.
 
The cyclone is currently over 24C sea-surface temperatures (SSTs)
and located within a very dry environment.  Over the next couple of
days, Henriette will enter an area of gradually increasing SSTs.  At
the same time, an approaching longwave trough will bring colder
temperatures aloft near Henriette, which will increase the
instability.  The majority of the model guidance indicates this will
be enough to reignite convection and cause Henriette to restrengthen
to a tropical storm.  The peak intensity forecast in about 72 hours
has been lowered slightly from the previous NHC forecast, and now
lies between the middle and upper end of the guidance.  Beyond day
4, wind shear from the longwave trough and cooling SSTs should lead
to steady weakening as Henriette moves farther into the
mid-latitudes.
 
Given the high likelihood of regeneration back into a tropical
cyclone and subsequent restrengthening, NHC will be maintaining
advisories during the post-tropical phase.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  08/2100Z 19.9N 143.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 12H  09/0600Z 20.7N 145.1W   30 KT  35 MPH...POST-TROP/REMNT LOW
 24H  09/1800Z 21.9N 147.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  10/0600Z 23.3N 149.8W   40 KT  45 MPH...TROPICAL CYCLONE
 48H  10/1800Z 25.0N 152.0W   50 KT  60 MPH
 60H  11/0600Z 26.9N 154.3W   55 KT  65 MPH
 72H  11/1800Z 29.1N 156.9W   60 KT  70 MPH
 96H  12/1800Z 33.5N 161.5W   55 KT  65 MPH
120H  13/1800Z 39.0N 165.9W   45 KT  50 MPH
 
$$
Forecaster Hagen
 
NNNN