Tropical Storm Pena

478 
WTPA44 PHFO 092044
TCDCP4
 
Tropical Storm Pena Discussion Number  13
NWS Central Pacific Hurricane Center Honolulu HI   CP042026
Issued by NWS National Hurricane Center Miami FL
1100 AM HST Mon Nov 09 2026
 
 
There has been little change in Tropical Storm Pena's organization. 
In fact, based on the first several visible satellite images of the 
day, it appears the low-level circulation is poorly organized and 
potentially open on the western side of the system. This would agree 
with an analysis of scatterometer and microwave data discussed in 
the previous advisory. Additionally, a new RCM2 Synthetic Aperture 
Radar (SAR) overpass shows the low-level center well west of the 
deep convection and the max wind band. The wind radii and center 
position have been updated accordingly. Based on the SAR data and 
satellite intensity estimates, Pena is maintained as a 35 kt 
tropical storm for this advisory, though this could be generous.
 
The initial motion is analyzed as 270/10 kt, with the forward motion 
somewhat uncertain due to the new initial position. Pena is forecast 
to continue generally westward over the next couple of days as it is 
steered by a low- to mid-level ridge to the north. Beyond 48 h, the 
cyclone should turn gradually toward the west-northwest and 
accelerate as a weakness develops in the ridge due to a shortwave 
trough moving across the northwestern Pacific. The track guidance 
continues to remain in good agreement on this scenario, and no 
significant changes were made to the track forecast.
 
Pena is no longer forecast to intensify, despite somewhat favorable 
environmental conditions. This general philosophy agrees with the 
current broad structure of the system, which appears unlikely to 
improve based on the latest dynamical model fields. Toward the end 
of the forecast period, vertical wind shear is expected to increase 
out of the west-southwest, which, combined with increasingly dry 
mid-level air, could allow Pena to dissipate or become a remnant 
low. For continuity, however, Pena is shown as a tropical cyclone 
through the forecast period. The latest NHC intensity forecast lies
near the middle of the guidance envelope.
 
Given that multiple independent data sources continue to suggest
that Pena is losing organization, it remains possible that Pena
dissipates within the next couple of days.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/2100Z 11.5N 161.4W   35 KT  40 MPH
 12H  10/0600Z 11.5N 163.0W   35 KT  40 MPH
 24H  10/1800Z 11.2N 165.3W   35 KT  40 MPH
 36H  11/0600Z 11.1N 167.4W   35 KT  40 MPH
 48H  11/1800Z 11.2N 170.1W   35 KT  40 MPH
 60H  12/0600Z 11.6N 173.1W   35 KT  40 MPH
 72H  12/1800Z 12.3N 176.5W   35 KT  40 MPH
 96H  13/1800Z 13.7N 177.5E   35 KT  40 MPH
120H  14/1800Z 14.6N 173.3E   35 KT  40 MPH
 
$$
Forecaster Mahoney