Tropical Storm Pena Forecast Discussion
|
Español: Aviso Publico Discusión |
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