Tropical Cyclone Discussion

069
WTPA43 PHFO 251453
TCDCP3
 
Tropical Depression Three-C Discussion Number   1
NWS Central Pacific Hurricane Center Honolulu HI   CP032026
Issued by NWS National Hurricane Center Miami FL
500 AM HST Sun Oct 25 2026
 
The system we have been monitoring near the International Date Line 
that was recently designated CP94 has become better organized early 
this morning. Showers and thunderstorm activity began to show signs 
of organization late yesterday, and an overnight scatterometer pass 
indicated that a small but well-defined circulation had formed. In 
addition, there was a WSF-M microwave pass at 0532 UTC, which 
showed curved bands were present on the 37-GHz channel, especially 
on the northern semi-circle of the system. Since that time, 
Himawari-9 and GOES-18 satellite imagery shows the system exhibiting 
a bursting convective pattern close to or just to the north of the 
estimated center. Subjective Dvorak estimates from both JTWC and 
Honolulu were T1.5/25 kt. However, the earlier scatterometer pass 
also showed a peak wind retrieval of 32 kt. Based on the system's 
structural improvement on satellite imagery overnight, advisories 
are being initiated on Tropical Depression Three-C at this time. The 
initial intensity is set at 30 kt, though this could be conservative 
given the earlier scatterometer data.
 
The depression's initial motion is east-northeastward, or 075/6 kt. 
The system is currently embedded in deep-layer westerly flow, both 
from an equatorward low-level westerly wind burst, and an 
upper-level westerly flow from an approaching short-wave trough to 
the north of the depression. These combined features should maintain 
the system on an eastward track for the next several days. The 
initial NHC track forecast blends the latest global model guidance 
from the GFS and ECMWF solutions. This track will take the tropical 
cyclone as a weakening system near Johnson Atoll in about 60-72 h. 
It is worth noting there is a lot of spread in the along-track 
direction, likely related to uncertainty in the vertical steering 
depth the system will feel over the next few days, so this first 
track forecast is a little lower confidence than usual.
 
The depression could already be close to tropical storm intensity 
given the earlier scatterometer data, and environmental conditions 
appear mostly favorable for the next 12-24 h with deep-layer shear 
in the 5-15 kt range with plenty of warm water and deep-layer 
moisture. However, the approaching mid-latitude trough to its north 
is expected to soon increase the westerly shear over the system, 
likely limiting the intensity of the tropical cyclone. Thus, only 
some slight intensification is shown over the next 12-24 h, with the 
storm plateauing as a 35 kt tropical storm through the early part of 
this week. By mid-week, SHIPS guidance shows this westerly shear 
increasing above 40 kt, and most of the guidance responds by showing 
the system quickly becoming separated from its deep convection as 
the circulation becomes increasingly elongated. The initial NHC 
intensity forecast therefore shows the cyclone degenerating into a 
remnant low in about 72 h, and dissipating shortly thereafter. This 
forecast is in good agreement with the global model guidance. 
 
Based on the initial track and intensity forecast, no watches are 
required for Johnston Atoll at this time, though interests there 
should continue to monitor the latest forecast updates related to 
this system.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/1500Z 14.6N 179.3W   30 KT  35 MPH
 12H  26/0000Z 14.7N 178.4W   35 KT  40 MPH
 24H  26/1200Z 14.7N 177.0W   35 KT  40 MPH
 36H  27/0000Z 14.4N 175.0W   35 KT  40 MPH
 48H  27/1200Z 14.6N 173.0W   35 KT  40 MPH
 60H  28/0000Z 15.5N 171.5W   30 KT  35 MPH
 72H  28/1200Z 16.5N 169.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  29/1200Z...DISSIPATED