Issued at 200 AM PDT Tue Oct 28 2025
000 WTPZ43 KNHC 280849 TCDEP3 Tropical Storm Sonia Discussion Number 15 NWS National Hurricane Center Miami FL EP182025 200 AM PDT Tue Oct 28 2025 The satellite presentation of Sonia has changed little since the previous advisory, with a small area of deep convection persisting over or near the cyclone’s low-level center. The latest subjective Dvorak current intensity estimates from TAFB and SAB are 2.0/30 kt and 1.5/25 kt, respectively, while objective estimates from UW-CIMSS range from 33 to 38 kt. A timely 0507 UTC Metop-C ASCAT pass revealed a swath of 35-kt winds, with a peak vector of 36 kt. Taking into account possible undersampling in the satellite-derived winds and the persistence of convection over or near the center for roughly 12 hours, the initial intensity is raised to 40 kt for this advisory. Sonia is moving west-northwest, or 300 degrees, at 7 kt. A turn toward the west is expected later today as Sonia’s circulation becomes shallower and is steered by the low-level flow. The NHC forecast has been nudged slightly north of the previous track, reflecting the continued west-northwest motion observed since the last advisory. The forecast track lies closest to a blend of the HFIP Corrected Consensus and Google DeepMind ensemble mean guidance. Sonia’s days appear to be numbered as the cyclone continues to be affected by moderate to strong southerly wind shear, analyzed near 22 kt by UW-CIMSS. The shear is expected to increase slightly within about 12 hours, while Sonia moves over gradually cooling waters and into a drier mid-level environment. Simulated satellite imagery from the GFS and ECMWF indicates that deep convection should collapse in about 12 hours under these increasingly hostile conditions. This is expected to result in gradual weakening, with Sonia forecast to become a post-tropical remnant low tonight and dissipate on Thursday. The intensity forecast is unchanged from the previous advisory and remains close to a blend of the latest consensus and SHIPS guidance. FORECAST POSITIONS AND MAX WINDS INIT 28/0900Z 14.8N 122.8W 40 KT 45 MPH 12H 28/1800Z 15.0N 123.9W 35 KT 40 MPH 24H 29/0600Z 15.1N 125.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 29/1800Z 15.0N 127.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 30/0600Z 14.6N 129.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 30/1800Z...DISSIPATED $$ Forecaster Jelsema (CPHC)
Source link