979
WTPA42 PHFO 130841
TCDCP2

Potential Tropical Cyclone One-C Discussion Number   4
NWS Central Pacific Hurricane Center Honolulu HI   CP012026
Issued by NWS National Hurricane Center Miami FL
1100 PM HST Wed Aug 12 2026

Recent ASCAT data suggest that the circulation of the disturbance
has become more circular during the past several hours. However,
the strongest winds are still located almost 200 n mi to the
northeast of the center, and the system continues to lack enough
organized convection to be called a tropical cyclone.  The ASCAT
data showed 35 kt winds, and that remains the initial intensity.

The initial motion is a rather uncertain 275/9 kt. A large high
pressure system north of the Hawaiian Islands should steer the
system generally west-northwestward for the next several days.
While the guidance is in general agreement with this scenario, the
track guidance has shifted a bit to the south of the previous
guidance suite since the last advisory, and the previous forecast,
the HCCA corrected consensus model, and the Google DeepMind
ensemble mean are all near the north edge of the guidance envelope.
Since reformations of the center could occur as the disturbance
organizes, the new forecast track will be nudged only a little south
of the previous track at this time.  The track forecast, including
how close the center will come to Hawaii, will remain low
confidence until a better-defined center forms.

For the next two days or so, the environment looks generally
favorable for intensification. However, the ongoing sprawling
structure suggests this strengthening will be gradual.  As the
system passes near Hawaii, the environment should become somewhat
less favorable due to some southwesterly shear, interaction with
the island of Hawaii, and dry air entrainment. These conditions are
likely to slow or stop intensification. The new intensity forecast
is has some minor tweaks for the previous forecast, and it lies in
the center of the intensity guidance envelope. As noted in the
previous advisory, if the system tracks farther south of Hawaii
than forecast, it would stay in more favorable conditions and
likely get stronger than forecast.


Key Messages:

1. The disturbance is expected to become a tropical storm by
Thursday night and strengthen while it moves west-northwestward
near or over the Hawaiian Islands late this week and this weekend.
Although it is too soon to specify the exact location and magnitude
of impacts, residents should closely monitor the latest forecast
updates and ensure that they have their preparedness plan in place.

2. Heavy rainfall associated with the Potential Tropical Cyclone
will begin to impact the Big Island Friday, spreading westward
across the island chain during the weekend.  This rainfall may
produce life-threatening flooding and mudslides, especially in areas
of steep terrain.

3. There is an increasing risk of wind and wave impacts in the
Hawaiian Islands regardless of the exact track and intensity of the
system.  Hurricane or Tropical Storm Watches may be required for
portions of the Hawaiian Islands early Thursday.


FORECAST POSITIONS AND MAX WINDS

INIT  13/0900Z 14.8N 144.5W   35 KT  40 MPH...POTENTIAL TROP CYCLONE
 12H  13/1800Z 15.5N 145.7W   35 KT  40 MPH...POTENTIAL TROP CYCLONE
 24H  14/0600Z 16.5N 147.9W   40 KT  45 MPH...TROPICAL CYCLONE
 36H  14/1800Z 17.3N 150.4W   45 KT  50 MPH
 48H  15/0600Z 18.0N 153.0W   50 KT  60 MPH
 60H  15/1800Z 18.7N 155.4W   55 KT  65 MPH
 72H  16/0600Z 19.6N 158.0W   60 KT  70 MPH
 96H  17/0600Z 21.2N 163.6W   55 KT  65 MPH
120H  18/0600Z 22.8N 169.1W   60 KT  70 MPH

$$
Forecaster Beven