664
WTPZ43 KNHC 290832
TCDEP3

Post-Tropical Cyclone Sonia Discussion Number  19
NWS National Hurricane Center Miami FL       EP182025
200 AM PDT Wed Oct 29 2025

Sonia has succumbed to hostile environmental conditions, with
satellite imagery showing no deep convection near the low-level
center for about 15 hours.  Therefore, Sonia is being a declared
post-tropical cyclone.  The latest subjective satellite intensity
estimates from TAFB and SAB reflect this, deeming the system too
weak to classify.  A 0541 UTC Metop-B ASCAT pass revealed a large
area of 25-kt winds, with a peak wind vector of 26 kt.  Taking into
account the likelihood of some undersampling, the initial intensity
for the post-tropical remnant low of Sonia is set at 30 kt.

Sonia will continue moving westward during the next day or so,
steered by the low-level flow, while remaining embedded within a
hostile environment.  Regeneration of organized deep convection is
not expected, and the remnant low of Sonia is forecast to dissipate
by Thursday, if not sooner.

For additional information on the post-tropical remnant low please
see High Seas Forecasts issued by the National Weather Service,
under AWIPS header NFDHSFEPI, WMO header FZPN02 KWBC, and on the
web at ocean.weather.gov/shtml/NFDHSFEPI.php

FORECAST POSITIONS AND MAX WINDS

INIT  29/0900Z 15.3N 126.1W   30 KT  35 MPH...POST-TROPICAL
 12H  29/1800Z 15.2N 127.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 24H  30/0600Z 14.7N 129.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  30/1800Z...DISSIPATED

$$
Forecaster Jelsema (CPHC)