Tropical Cyclone Discussion

897
WTPZ45 KNHC 140236
TCDEP5
 
Hurricane Simon Discussion Number  27
NWS National Hurricane Center Miami FL       EP202026
800 PM MST Tue Oct 13 2026
 
After holding steady for the past 18-24 hours, Simon is
re-intensifying. The eye of the hurricane has become distinct, and
deep convection is more intense and symmetric around the eye. The
initial intensity has been increased to 95 kt near a Dvorak
classification from TAFB. Although Simon's peak winds appear to have
increased significantly, the hurricane remains tiny. The hurricane-
and tropical-storm-force winds are estimated to only extend up to 10
and 30 n mi from the center, respectively.
 
The compact hurricane is drifting westward off the coast of
west-central Mexico. The steering currents are expected to remain
very weak for the next couple of days, and most of the models show
Simon drifting southwestward during that time. By the end of the
week and over the weekend, the model solutions diverge
significantly, and the differences appear to be due to the location
and depth of Simon and a mid- to upper-level trough over the western
U.S. The new forecast shows a slower motion from days 3 to 5, in
better agreement with the latest models.
 
Some additional strengthening is possible tonight, and Simon could
become a major hurricane again. However, slow weakening seems
likely after that time due to an increase in vertical wind shear,
intrusions of dry air, and possibly ocean upwelling. The NHC
intensity forecast is raised from the previous one in the short
term, but is similar to the prior forecast beyond a couple of days.
 
Simon has been a very challenging storm to forecast, and confidence
for this cycle remains low given the weak steering, proximity to
land, very small size, and significant model spread.
 
Key Messages:
 
1. Simon could be near Las Islas Marias on Thursday, where a
Hurricane Watch remains in effect. Interests in west-central Mexico
and Baja California Sur should continue to closely monitor the
latest updates. Additional watches or warnings could be required
over the next day or two.
 
2. Large swells will likely affect portions of the coast of
west-central Mexico and Baja California Sur over the next several
days. These swells could cause life-threatening surf and rip current
conditions.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  14/0300Z 20.1N 107.6W   95 KT 110 MPH
 12H  14/1200Z 20.1N 107.8W  105 KT 120 MPH
 24H  15/0000Z 19.6N 108.2W   95 KT 110 MPH
 36H  15/1200Z 18.9N 108.5W   85 KT 100 MPH
 48H  16/0000Z 19.7N 108.1W   75 KT  85 MPH
 60H  16/1200Z 21.0N 108.0W   65 KT  75 MPH
 72H  17/0000Z 22.3N 108.8W   55 KT  65 MPH
 96H  18/0000Z 24.1N 109.7W   40 KT  45 MPH
120H  19/0000Z 27.2N 110.9W   30 KT  35 MPH...POST-TROP/REMNT LOW