Tropical Cyclone Discussion

916
WTPZ45 KNHC 092046
TCDEP5
 
Hurricane Simon Discussion Number  10
NWS National Hurricane Center Miami FL       EP202026
300 PM CST Fri Oct 09 2026
 
An intermittent warm spot in the CDO of Simon has been present since 
this morning, co-located with a small pinhole-like eye noted in 
visible imagery. The initial intensity of 90 kt is based primarily 
on the latest TAFB Dvorak fix, though this is very uncertain due to 
the very small size of Simon and intensity estimates range from 
around 65 kt (DMINT) to 97 KT (RCM-1 SAR). The SAR data this morning 
indicated the system has an RMW near 5 n mi, highlighting how small 
it is.

Simon has continued to strengthen today, although at a slightly 
slower rate since this morning. Further rapid intensification is 
still anticipated but the exact timing of when the rate might pick 
up again is highly uncertain. Small hurricanes like Simon are 
particularly susceptible to large and rapid fluctuations in 
intensity. In the short term, no changes of note were made to the 
NHC intensity forecast, which remains at the high end of the 
guidance envelope. 

The main challenge with this forecast is how sensitive it is to the 
exact track Simon takes over the next 2 days and whether or not it 
moves inland over the Mexican states of Colima and Jalisco. A track 
slightly east of the NHC official forecast track will cause Simon to 
quickly dissipate and minimize the threat of wind impacts farther 
north in Mexico. However, a track just to the west would likely 
allow Simon to move much farther north as a hurricane. At this time, 
the difference between these track scenarios is less than the 
average error of NHC forecasts. Most of the deterministic global 
models shifted slightly east this cycle, but ensemble guidance 
indicates both scenarios are still plausible. The NHC track and 
intensity forecast therefore is largely unchanged and continues to 
show Simon tracking farther north than it might realistically make 
it to emphasize that risk. 
 
 
Key Messages:
 
1. Catastrophic wind and life-threatening storm surge impacts are
likely along a portion of the west-central coast of Mexico, and a
Hurricane warning is in effect from Punta San Telmo to Punta Mita.
Preparations to protect life and property should be completed by
late today.
 
2. Heavy rainfall associated with Simon will impact portions of 
southwestern Mexico through this weekend. This rainfall will produce 
life-threatening flooding and mudslides, especially in areas of 
steep terrain.
 
3. Swells will affect portions of the southwestern and west-central
coast of Mexico through the weekend. These swells are likely to
cause life-threatening surf and rip current conditions. Please
consult products from your local weather office.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/2100Z 16.2N 104.7W   90 KT 105 MPH
 12H  10/0600Z 16.6N 104.9W  110 KT 125 MPH
 24H  10/1800Z 17.5N 105.0W  125 KT 145 MPH
 36H  11/0600Z 18.6N 105.1W  115 KT 130 MPH
 48H  11/1800Z 20.0N 105.3W   95 KT 110 MPH...INLAND
 60H  12/0600Z 21.4N 105.5W   75 KT  85 MPH...OVER WATER
 72H  12/1800Z 22.8N 105.8W   60 KT  70 MPH...INLAND
 96H  13/1800Z 24.6N 106.4W   30 KT  35 MPH...POST-TROP/INLAND
120H  14/1800Z...DISSIPATED