Tropical Cyclone Discussion

384
WTPZ42 KNHC 221455
TCDEP2
 
Hurricane Polo Discussion Number   8
NWS National Hurricane Center Miami FL       EP172026
900 AM CST Tue Sep 22 2026

Polo has a spectacular presentation on geostationary and microwave 
satellite imagery, with a small well-defined eye surrounded by a 
symmetrical area of very deep convection.  The upper-level outflow 
is quite prominent over all quadrants of the system and there are 
strong convective banding features surrounding the central dense 
overcast.  A Subjective Dvorak data T-number from TAFB just after 
1200 UTC was 7.0, corresponding to 140 kt, and assuming a little 
more strengthening since that time, the advisory intensity is set 
to 145 kt. Despite its great strength, Polo remains a relatively
small cyclone with its hurricane and tropical-storm-force winds
estimated to only extend about 30 and 80 n mi from the eye,
respectively.
 
The powerful hurricane appears to have stopped moving eastward, and 
it is now drifting northward at around 360/2 kt.  A deep-layer 
ridge is becoming established over Mexico.  This evolution of the 
steering pattern should result in Polo turning west-northwestward 
and beginning to move parallel, but fairly close to, the coast of 
Mexico over the next couple of days.  There is still uncertainty as 
to how close the hurricane will get to the coast, and some wind, 
rain, and surf impacts appear likely when Polo makes its closest 
approach.  A Tropical Storm Warning has been issued for a portion 
of the coast of Mexico and the Tropical Storm Watch has been 
extended westward.  Polo should begin to pull away from southwestern 
Mexico Thursday night and Friday as the ridge keeps the system on a 
west-northwestward to northwestward path.  The steering currents 
become more uncertain over the weekend when Polo reaches the western 
edge of the ridge and nears Tropical Storm Odalys to its west. 
However Polo is likely to slow down and move more northward around 
day 5.  Little change was made to the NHC track forecast, which lies 
on the northern side of the guidance envelope.
 
Polo should remain in an environment that is very  conducive for 
strengthening during next couple of days.  It should be noted that 
for these intense hurricanes, inner-core changes such as eyewall 
replacements are quite common.  These changes can lead to some 
fluctuations in intensity.  However, Polo is likely to remain a 
dangerous major hurricane through the forecast period.


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 now in effect for portions of 
southwestern Mexico, and the Tropical Storm Watch has been extended 
westward along the coast.  Interests in these areas should closely 
monitor updates to the forecast.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/1500Z 14.7N 101.6W  145 KT 165 MPH
 12H  23/0000Z 15.0N 101.5W  155 KT 180 MPH
 24H  23/1200Z 15.4N 101.9W  150 KT 175 MPH
 36H  24/0000Z 16.1N 102.8W  150 KT 175 MPH
 48H  24/1200Z 16.7N 104.2W  140 KT 160 MPH
 60H  25/0000Z 17.1N 105.9W  130 KT 150 MPH
 72H  25/1200Z 17.3N 107.5W  125 KT 145 MPH
 96H  26/1200Z 18.4N 110.8W  115 KT 130 MPH
120H  27/1200Z 20.8N 112.7W  105 KT 120 MPH