497
WTPZ43 KNHC 270239
TCDEP3
TROPICAL STORM SONIA DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL EP182025
800 PM PDT SUN OCT 26 2025
SATELLITE IMAGERY INDICATES THAT SONIA HAS DEGRADED DURING THE PAST
12 TO 24 H AS PERSISTENT MODERATE SOUTHERLY WIND SHEAR HAS DISPLACED
DEEP CONVECTION MOSTLY NORTH OF THE LOW-LEVEL CIRCULATION CENTER.
THE CIRCULATION IS NOW PARTIALLY EXPOSED ON THE SOUTHERN EDGE OF THE
DEEP CONVECTION. BASED ON A BLEND OF THE SUBJECTIVE DVORAK AND
OBJECTIVE INTENSITY ESTIMATES, THE INITIAL INTENSITY IS SET AT 40
KT.
SONIA IS MOVING WEST-NORTHWESTWARD AT ABOUT 295/5 KT, AND THIS
GENERAL MOTION IS EXPECTED TO PERSIST OVER THE NEXT DAY OR SO, AS
THE SUBTROPICAL RIDGE REMAINS POSITIONED TO THE NORTH. BY TUESDAY,
SONIA SHOULD GRADUALLY TURN TOWARD THE WEST AS IT BECOMES A SHALLOW
SYSTEM EMBEDDED WITHIN THE LOW-LEVEL TRADE-WIND FLOW. THE NHC TRACK
FORECAST IS LITTLE CHANGED FROM THE PREVIOUS ONE AND REMAINS CLOSE
TO THE MULTI-MODEL CONSENSUS AIDS.
MODERATE SOUTHERLY WIND SHEAR CONTINUES TO AFFECT SONIA AND IS
EXPECTED TO GENERALLY HOLD STEADY DURING THE NEXT COUPLE OF DAYS, IF
NOT INCREASE SLIGHTLY. THIS, COMBINED WITH COOLER WATERS AND A
DRIER, MORE STABLE ENVIRONMENT AHEAD OF THE CYCLONE, SHOULD RESULT
IN A GRADUAL WEAKENING TREND BEGINNING WITHIN THE NEXT 12 TO 24
HOURS. SIMULATED SATELLITE IMAGERY FROM THE GFS AND ECMWF SHOWS
CONVECTION DIMINISHING SIGNIFICANTLY BY TUESDAY, SUGGESTING THAT
SONIA WILL LOSE ORGANIZED DEEP CONVECTION AND BECOME A POST-TROPICAL
REMNANT LOW BY THAT TIME. DISSIPATION IS EXPECTED BY WEDNESDAY AS
THE REMNANT LOW CONTINUES WESTWARD AND OPENS INTO A TROUGH. THE
UPDATED NHC INTENSITY FORECAST CLOSELY FOLLOWS THE CONSENSUS AIDS
AND REMAINS SIMILAR TO THE PREVIOUS ONE.
FORECAST POSITIONS AND MAX WINDS
INIT 27/0300Z 14.1N 120.0W 40 KT 45 MPH
12H 27/1200Z 14.3N 120.6W 40 KT 45 MPH
24H 28/0000Z 14.6N 121.7W 35 KT 40 MPH
36H 28/1200Z 14.8N 123.2W 35 KT 40 MPH
48H 29/0000Z 14.8N 124.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 29/1200Z 14.7N 126.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 30/0000Z...DISSIPATED
FORECASTER GIBBS (CPHC)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page