000
WTPZ45 KNHC 090846
TCDEP5
 
Hurricane Simon Discussion Number   8
NWS National Hurricane Center Miami FL       EP202026
300 AM CST Fri Oct 09 2026
 
Simon has quickly strengthened this morning.  A EUMETSAT METOP-B
Microwave Humidity Sounder (MHS) image revealed a small banding eye
feature, and the IR-BD curve enhancement indicates -83C cold cloud
tops associated with a small central dense overcast over the
surface center.  Water vapor imagery and satellite wind data
indicate developing cyclonic outflow above 200 mb.  Based on the
much improved cloud pattern and the TAFB subjective intensity
estimate of T4.5 (77 kt), the initial intensity is increased to 80
kt.
 
Simon's small, intense inner core, favorable environmental 
conditions, low shear, very warm oceanic temperatures, and high 
mid-level moisture content all support a rapid intensification 
event, which appears to be well underway.  Further significant 
strengthening is expected, and the cyclone is forecast to be a very 
dangerous major hurricane when it approaches the coast of Mexico.  
The guidance also shows compact Simon quickly weakening and over the 
high mountainous terrain by early next week.  The NHC forecast is 
once again hedged toward the high end of the guidance, in best 
agreement with the HFIP-HCCA model.
 
Simon's initial motion is estimated to be northwestward, or
315/4 kt.  A northward motion is forecast by early Saturday while 
high pressure over central Mexico weakens and shifts eastward, in 
response to an amplifying mid-tropospheric trough approaching Baja 
California.  The HiRes global models (ECM/GFS/CMC/UKM), HAFS 
hurricane models and the NOAA GEFS AI ensemble mean continue to 
agree more with Simon approaching the west-central coast of Mexico 
on Sunday.  The HCCA and the Google DeepMind ensemble mean have 
been somewhat inconsistent during the past 2 cycles, 
windshield-wipering with a track either inland or just offshore 
beyond the 48-hour period.  Additionally, the along-track forward 
speeds have also become inconsistent, which has slightly affected 
the wind impact timing.  To minimize these track forecast 
inconsistencies, the NHC forecast blends the various consensus aids 
and is nudged to the right of the HCCA and GDM ensemble mean 
solutions.
 
 
Key Messages:
 
1. Simon is expected to approach the west-central coast of Mexico
as a major hurricane on Saturday.
 
2. Life-threatening wind and storm surge impacts are expected 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 Friday.
 
3. Heavy rainfall associated with Simon will impact portions of 
southwestern Mexico through this weekend. This rainfall may produce 
life-threatening flooding and mudslides, especially in areas of 
steep terrain.
 
4. 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  09/0900Z 15.8N 104.5W   80 KT  90 MPH
 12H  09/1800Z 16.1N 104.7W  100 KT 115 MPH
 24H  10/0600Z 16.7N 104.9W  120 KT 140 MPH
 36H  10/1800Z 17.6N 105.0W  125 KT 145 MPH
 48H  11/0600Z 18.6N 105.1W  120 KT 140 MPH
 60H  11/1800Z 19.9N 105.3W  110 KT 125 MPH...INLAND
 72H  12/0600Z 21.4N 105.4W   80 KT  90 MPH...OVER WATER
 96H  13/0600Z 23.7N 106.0W   60 KT  70 MPH...INLAND
120H  14/0600Z 24.9N 106.3W   35 KT  40 MPH...INLAND
 
$$
Forecaster Roberts