Potential Tropical Cyclone One-C

000
WTPA42 PHFO 122044
TCDCP2
 
Potential Tropical Cyclone One-C Discussion Number   2
NWS Central Pacific Hurricane Center Honolulu HI   CP012026
Issued by NWS National Hurricane Center Miami FL
1100 AM HST Wed Aug 12 2026
 
 
The disturbance remains a broad and sprawling system.  The
associated deep convection is poorly organized and curved banding
features are currently lacking.  An ASCAT-B scatterometer pass
showed some wind vectors near 35 kt, although these winds were
located well northeast, over 200 n mi, from the estimated center.
Therefore the initial intensity is set at 35 kt for this advisory.
Note that the circulation is not well enough defined and the deep
convection is not sufficiently well-organized for the system to be
considered a tropical cyclone yet, despite the stronger winds.
 
Since the system has a large overall cyclonic circulation, a
unique center has become difficult to pin down.  There appear
to be some swirls rotating around the overall gyre.  My best
estimate of the initial motion is 260/8 kt.  There hasn't been much
change to the track forecast or reasoning behind the forecast.  A
large mid-level anticyclone to the north of One-C should result in
a mostly west-northwestward track over the next several days.  The
official track forecast is basically unchanged from the previous
one, and close to the dynamical consensus and Google DeepMind
Guidance.  Given that the system is still in the formative stage,
the precise track is still somewhat uncertain.
 
Sea surface temperatures, vertical wind shear and low- to
mid-level humidities should support gradual strengthening during
the next few days.  Based on the intensity models, the system is
expected to be nearing hurricane strength by the time it nears the
Hawaiian Islands.  However, an upper-level low/trough could limit
strengthening while the system passes near or over the Islands.
 
Key Messages:
 
1. The disturbance is expected to become a tropical storm on
Thursday 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 system will begin to impact
the Big Island Friday, spreading westward into Maui Saturday, and
Lanai, Molokai, Oahu and Kauai on Sunday.  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  12/2100Z 14.7N 142.6W   35 KT  40 MPH...POTENTIAL TROP CYCLONE
 12H  13/0600Z 15.2N 143.7W   35 KT  40 MPH...POTENTIAL TROP CYCLONE
 24H  13/1800Z 15.9N 145.1W   40 KT  45 MPH...TROPICAL CYCLONE
 36H  14/0600Z 17.0N 147.1W   45 KT  50 MPH
 48H  14/1800Z 17.9N 149.5W   50 KT  60 MPH
 60H  15/0600Z 18.6N 152.0W   55 KT  65 MPH
 72H  15/1800Z 19.3N 154.6W   60 KT  70 MPH
 96H  16/1800Z 21.0N 160.0W   55 KT  65 MPH
120H  17/1800Z 22.9N 165.8W   60 KT  70 MPH
 
$$
Forecaster Pasch