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)