Tropical Cyclone Discussion

426
WTPZ45 KNHC 150232
TCDEP5
 
Tropical Storm Simon Discussion Number  31
NWS National Hurricane Center Miami FL       EP202026
800 PM MST Wed Oct 14 2026
 
Simon remains a tiny storm. The earlier Air Force Hurricane Hunter 
data along with an ASCAT-C pass indicate that the tropical- 
storm-force wind field is very small, only extending up to 30 n mi 
from the center. The last pass of the aircraft through the center 
suggested that Simon has fallen below hurricane strength, and the 
pressure has risen to about 991 mb. The initial intensity is 
estimated to be around 55 kt based on a combination of the aircraft 
data and various satellite fixes. Satellite images show that Simon 
is producing a concentrated area of deep convection over the center 
that has been increasing in coverage over the past few hours.
 
The compact storm is moving southwestward at about 4 kt. The models 
suggest that Simon will move even slower or possibly stall over the 
next day or so as it remains caught in weak steering currents. 
However, a turn to the northwest seems likely on Friday when the 
system moves on the east side of a deep-layer cut off low. The NHC 
track forecast has been nudged to the left of the previous one, 
toward the latest HCCA and GDMI guidance.
 
Simon has weakened at a rapid rate of about 40 kt over the past 24 
hours. This highlights how challenging it is to predict intensity 
changes in very compact systems like this one.  The environmental 
conditions appear generally favorable for the next 12 to 24 hours, 
so little change in strength is predicted in the short term. 
However, after that time, a notable increase in southwesterly 
vertical wind shear and intrusion of dry air should cause the system 
to decay. This forecast is quite a bit lower than the previous one 
given the lower initial intensity and trending toward the middle of 
the guidance envelope. In fact, it would not be surprising if Simon 
weakens faster than shown here.
 
Key Messages:
 
1. Interests in Baja California Sur should continue to closely
monitor the latest updates as Simon is expected to pass near or
west of that area this weekend.
 
2. Large swells will likely affect portions of the coast of
west-central Mexico and Baja California Sur over the next few days.
These swells could cause life-threatening surf and rip current
conditions.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  15/0300Z 19.1N 108.6W   55 KT  65 MPH
 12H  15/1200Z 19.0N 108.5W   55 KT  65 MPH
 24H  16/0000Z 19.1N 108.6W   50 KT  60 MPH
 36H  16/1200Z 19.7N 109.1W   45 KT  50 MPH
 48H  17/0000Z 20.8N 110.3W   40 KT  45 MPH
 60H  17/1200Z 21.7N 111.2W   35 KT  40 MPH
 72H  18/0000Z 22.8N 112.3W   30 KT  35 MPH
 96H  19/0000Z 24.6N 113.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  20/0000Z 26.6N 114.8W   20 KT  25 MPH...POST-TROP/REMNT LOW