Tropical Cyclone Discussion

940
WTPZ41 KNHC 191456
TCDEP1
 
Tropical Storm Trudy Discussion Number  25
NWS National Hurricane Center Miami FL       EP212026
800 AM MST Mon Oct 19 2026
 
Convection has reignited near Trudy this morning, with very cold
cloud tops below -80C evident north and east of the estimated center
on infrared satellite imagery. However, an earlier GPM microwave
pass indicated that westerly wind shear is affecting the tropical
storm, with shear estimated at around 15 kt based on GFS and ECMWF
SHIPS guidance. Recent objective Dvorak intensity estimates from
UW-CIMSS range from 42-55 kt. Given the renewed convective activity
and the relatively consistent intensity estimates, the initial
intensity is maintained at 50 kt for this advisory.
 
Trudy is moving westward around 5 kt, steered by a low- to mid-level
ridge centered to its north. A westward to west-southwestward
motion, accompanied by a slower forward speed, is expected  through
tonight. A gradual turn toward the northwest is forecast on Tuesday
as a strong deep-layer trough advances southeastward over the
eastern Pacific toward the West Coast of the United States. The
latest NHC forecast track has been nudged slightly to the left of
the previous forecast, toward the HCCA and Google DeepMind
solutions.
 
Despite the recent uptick in convection, cooler sea surface
temperatures, increasingly dry mid-level air and an unfavorable
upper-level wind environment are expected to support weakening over
the next couple of days. ECMWF simulated satellite imagery suggests
that Trudy may struggle to maintain organized convection on Tuesday,
and the latest forecast calls for the system to become post-tropical
within 24 h. The latest NHC forecast is similar to the previous
forecast, lying near the upper end of the intensity guidance through
12 h and near the middle of the guidance thereafter. Trudy is
forecast to dissipate by 72 h.
 
Large swells will continue to affect the coast of southwestern
Mexico and west-central Mexico today, causing life-threatening surf
and rip current conditions at the beaches.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  19/1500Z 19.5N 108.5W   50 KT  60 MPH
 12H  20/0000Z 19.5N 108.7W   40 KT  45 MPH
 24H  20/1200Z 19.5N 109.4W   35 KT  40 MPH...POST-TROPICAL
 36H  21/0000Z 19.9N 110.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 48H  21/1200Z 20.3N 110.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  22/0000Z 20.9N 111.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  22/1200Z...DISSIPATED