Advisories

000
WTPZ45 KNHC 112112 CCA
TCDEP5
 
Hurricane Simon Discussion Number  18...Corrected
NWS National Hurricane Center Miami FL       EP202026
300 PM CST Sun Oct 11 2026

Corrected spelling of Sierra in first sentence.

Simon is still a Category 4 hurricane, but appears to be feeling the 
effects of the nearby high terrain of the Sierra Madre Mountains as 
the inner core is brushing up against the Mexican coast. The eye 
remains observed on geostationary satellite imagery, but is more 
cloud filled than earlier with warmer surrounding cloud tops. While 
the 18 UTC subjective Dvorak fix was still at T6.5/125 kt, the 
objective intensity estimates have continued to fall, with values 
now in the 109-115 kt range. Therefore, the initial intensity is 
being lowered to 115 kt for this advisory. An earlier Synthetic 
Aperture Radar (SAR) RCM-1 pass was very useful to adjust the 34- 
50- and 64-kt radii of Simon as the hurricanes wind field continues 
to shrink in size. 

Simon has stubbornly maintained a north-northwestward motion, 
roughly parallel to the coastline, estimated at 335/5 kt. It is now 
looking increasingly likely that Simon will avoid making a direct 
landfall in the short-term, though its eastern inner core will 
likely produce hurricane conditions as the storm continues to move 
north-northwestward from Playa Perula to Cabo Corrientes this 
afternoon and evening. The steering ridge centered over the Texas 
coast is likely to maintain this motion now for the next several 
days, though with some slowdown in the motion due to a weaker but 
competing ridge located to Simon's southwest. On Tuesday into 
Wednesday, a large short-wave trough is forecast to move across the 
southwestern United States and this feature should provide enough 
southwesterly environmental flow to turn the hurricane to the 
northeast, finally reaching the coast of Mexico in 60-72 h. Compared 
to this morning, the guidance has shifted westward and slower once 
again, and there remain some outlier solutions like the GFS that 
want to turn Simon southwestward beyond 48 h. However, the majority 
of the ensemble guidance (European-EPS, Google DeepMind) do show 
this slow recurving solution back into Mexico. The NHC track 
forecast is a little bit west and slower for the first 36-48 h, but 
then bends back to the previous forecast track thereafter, still 
showing Simon moving inland and dissipating in the day 3-4 period.  
This forecast still remains low confidence. 

Intensity wise, it is now looking more likely that Simon will not 
weaken as much as originally expected, now that it is only brushing 
up against the coast instead of part of its inner core moving 
inland. Still, the high topography in Jalisco should still have a 
negative effect, which has already been seen in Simon's wind field 
shrinking in size. The hurricane-regional models still show 
significant weakening over the next 12-24 h, even the ones that only 
skirt the coast of Mexico, and the NHC intensity forecast still 
shows a fast rate of weakening during that time. However, other 
environmental conditions remain very favorable, as shear stays under 
10 kt, and sea-surface temperatures warm to 31-32 C as Simon passes 
north of Cabo Corrientes and enters waters that have been unaffected 
by recent tropical cyclones (Polo and Rachel). However, there will 
be a significant amount of nearby dry air and it remains to be seen 
how intact Simon's inner core will remain over the next 24 h of near 
land interaction. The latest NHC intensity forecast now shows Simon 
maintaining hurricane intensity, and this forecast could still be 
low if the inner core remains more robust than the hurricane 
regional models are forecasting. This forecast is now on the higher 
end of the intensity guidance aids, but is under the SHIPS guidance 
this cycle, and also remains low confidence. 
 
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 El Roblito. 
Residents should continue to shelter in a safe room to ride out the 
storm as the most significant hazards with Simon are now ongoing.

2. Simon is now expected to approach the coast of west Mexico later 
this week, where Hurricane conditions are now possible along the 
coast of El Roblito to Bahia Tempehuaya. A Hurricane Watch is now in 
effect for this region. 

3. Heavy rainfall associated with Simon will impact portions of 
southwestern and west-central Mexico over the next few days. This 
rainfall will 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 over the next few days. 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  11/2100Z 19.6N 105.8W  115 KT 130 MPH
 12H  12/0600Z 20.2N 106.1W   90 KT 105 MPH
 24H  12/1800Z 21.0N 106.6W   80 KT  90 MPH
 36H  13/0600Z 21.6N 106.9W   75 KT  85 MPH
 48H  13/1800Z 22.2N 107.1W   75 KT  85 MPH
 60H  14/0600Z 22.8N 107.0W   75 KT  85 MPH
 72H  14/1800Z 23.4N 106.6W   75 KT  85 MPH
 96H  15/1800Z 24.0N 105.9W   30 KT  35 MPH...POST-TROP/INLAND
120H  16/1800Z...DISSIPATED
 
$$
Forecaster Papin