Tropical Cyclone Discussion

633
WTPZ42 KNHC 222047
TCDEP2
 
Hurricane Polo Discussion Number   9
NWS National Hurricane Center Miami FL       EP172026
300 PM CST Tue Sep 22 2026
 
A NOAA Hurricane Hunter aircraft investigated Hurricane Polo this
afternoon and found that it had strengthened even more since this
morning.  The highest 700 mb flight-level winds were 168 kt, which
corresponds to 151 kt at the surface using a standard reduction
factor.  However, the aircraft also found that the central pressure
had dropped to an extremely low value of about 892 mb. This would
typically support even higher winds than 151 kt, so the advisory
intensity is set conservatively to 155 kt.  The system continues to
look very impressive on satellite imagery with very deep convection
and well-defined upper-level outflow.  The radial profile of the
aircraft wind data show hints of a secondary wind maximum so a
concentric eyewall may be developing.
 
Aircraft and satellite center fixes indicate little movement over
the past few hours.  Global models show a mid-tropospheric ridge
becoming established over Mexico during the next couple of days.
This evolution of the steering pattern should result in a
west-northwestward track in the 48- to 72-hour time frame.  In 4-5
days, the steering currents are more uncertain.  However, Polo
appears likely to slow down and turn more northward by that time.
The official forecast is very similar to the previous NHC track.
 
Polo should remain in a very conducive environment of low vertical 
wind shear, extremely warm ocean waters, and a very moist low- to 
mid-level air mass for the next several days.  Therefore even more 
strengthening is possible.  Given the suggestion of concentric 
eyewall formation however, only a slight increase in intensity is 
forecast tonight and fluctuations in intensity are likely over the 
next few days.  However, the hurricane is expected to remain very 
intense through this week and, in fact, maintain category 5 strength 
for a couple of days.
 
Key Messages:
 
1. Heavy rainfall associated with Polo will impact coastal portions
of southwest Mexico through Thursday.  This rainfall may produce
life-threatening flooding and mudslides, especially in areas of
steep terrain.
 
2. A Tropical Storm Warning is in effect for portions of
southwestern Mexico, and the Tropical Storm Watch is in effect 
westward to Playa Perula. Interests in these areas should closely
monitor updates to the forecast.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/2100Z 14.6N 101.5W  155 KT 180 MPH
 12H  23/0600Z 15.0N 101.8W  160 KT 185 MPH
 24H  23/1800Z 15.5N 102.4W  160 KT 185 MPH
 36H  24/0600Z 16.2N 103.6W  155 KT 180 MPH
 48H  24/1800Z 16.7N 105.2W  150 KT 175 MPH
 60H  25/0600Z 17.0N 106.9W  130 KT 150 MPH
 72H  25/1800Z 17.4N 108.5W  130 KT 150 MPH
 96H  26/1800Z 18.7N 111.5W  115 KT 130 MPH
120H  27/1800Z 21.8N 113.0W  110 KT 125 MPH