Tropical Cyclone Discussion

757
WTNT42 KNHC 260848
TCDAT2
 
Tropical Storm Gonzalo Discussion Number   6
NWS National Hurricane Center Miami FL       AL072026
800 AM CVT Sat Sep 26 2026
 
The convective structure of Gonzalo has not changed much during the 
last 6 hours.  It continues to be a sheared tropical cyclone, with 
the somewhat ill-defined low-level center exposed to the southwest 
of the convective mass due to 30 kt of southwesterly shear 
occurring over the cyclone.  The TAFB current intensity number is 
2.5/35 kt. Objective intensity estimates from UW-CIMSS range from 
34-41 kt. Based on these estimates as well as earlier scatterometer 
data, the intensity is held at 40 kt, but this could be a bit 
generous.

The initial motion is northward, or 350 degrees at 8 kt.  This 
general motion should continue for another day, followed by a 
deceleration and a turn toward the west-northwest by Monday.  The 
storm is already experiencing 30 kt of southwesterly vertical wind 
shear, and the shear is expected to increase to over 40 kt by hour 
12 of the forecast, so I expect the convection to continue moving 
farther away from the low-level center.  This should lead to Gonzalo 
becoming post-tropical by hour 24 or a bit sooner.  Model guidance 
is in good agreement that Gonzalo will weaken significantly over the 
next 36 hours, and the NHC forecast follows the guidance.  Earlier 
ASCAT data indicated the low-level circulation was becoming 
elongated.  If this trend continues, then Gonzalo could dissipate 
sooner than forecast.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/0900Z 17.6N  23.0W   40 KT  45 MPH
 12H  26/1800Z 18.9N  23.2W   35 KT  40 MPH
 24H  27/0600Z 20.1N  23.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  27/1800Z 20.7N  23.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  28/0600Z 21.1N  24.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  28/1800Z 21.3N  24.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  29/0600Z 21.5N  25.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  30/0600Z 21.9N  26.0W   15 KT  15 MPH...POST-TROP/REMNT LOW
120H  01/0600Z...DISSIPATED