000
WTPZ42 KNHC 241440
TCDEP2
 
Hurricane Polo Discussion Number  16
NWS National Hurricane Center Miami FL       EP172026
900 AM CST Thu Sep 24 2026

Satellite imagery shows that while Polo remains a powerful 
hurricane, there have been some structural changes during the past 
few hours. First, an AMSR3 overpass a few hours ago showed a new 
outer eyewall was forming, indicating that the hurricane is about 
to begin another eyewall replacement cycle. Second, while the eye 
and the central convective features remain well defined, there is 
now an outer band in the southwestern semicircle with infrared cloud 
top temperatures colder than those currently seen in the inner core. 
The various satellite intensity estimates have nudged downward, and 
the initial intensity of 135 kt is at the upper edge of the 
estimates.

Polo is turning more westward with the initial motion now 295/9 kt. 
A mid-level ridge building westward from northern Mexico should 
steer the hurricane generally westward for the next 36 h or so.  
After that, a mid-latitude trough moving eastward across the 
northeastern Pacific should prevent the ridge from building farther 
west, with Polo likely to recurve northward and northeastward 
around the western end of the ridge.  The track guidance has come 
into much better agreement on this scenario, although there are 
significant differences in how fast the storm will move during the 
recurvature. One on side, the GFS, HCCA, Google DeepMind, and 
Florida State Super Ensemble are faster, and the official forecast 
leans towards them. On the other, the UKMET and the regional 
hurricane models are notably slower with their forward speed. 
Overall, the new forecast track is near the center of the guidance 
envelope and is similar to the previous forecast. The new track 
takes the center away from the southwestern coast of Mexico today 
and then has it passing over Baja California Sur in 96-120 h.

Fluctuations in strength seem likely over the next day or so while
Polo undergoes this new eyewall replacement and remains in 
favorable environmental conditions. The intensity forecast shows 
little change in strength at 12 h and some slight strengthening at 
24 h to try to account for the cycle.  After 24 h, a slow weakening 
is expected through 96 h as Polo encounters somewhat increased 
shear. The new forecast shows a sharp drop in intensity by 120 h 
as Polo crosses the Baja California peninsula. The new forecast 
lies near the upper edge of the intensity guidance.


Key Messages:
 
1. Heavy rainfall associated with Polo will impact coastal portions 
of southwest Mexico today. This rainfall may produce 
life-threatening flooding and mudslides, especially in areas of 
steep terrain.
 
2. Tropical storm conditions are expected across portions of the 
coast within the warning area from Tecpan de Galeana to Manzanillo 
for a few more hours.
 
3. Polo is forecast to approach the Baja California Peninsula early
next week as a hurricane. Interests there should closely monitor
the latest updates and ensure that they have their preparedness
plan in place.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/1500Z 16.8N 104.4W  135 KT 155 MPH
 12H  25/0000Z 17.0N 105.8W  135 KT 155 MPH
 24H  25/1200Z 17.1N 107.8W  140 KT 160 MPH
 36H  26/0000Z 17.4N 109.6W  135 KT 155 MPH
 48H  26/1200Z 18.2N 111.2W  130 KT 150 MPH
 60H  27/0000Z 19.4N 112.5W  125 KT 145 MPH
 72H  27/1200Z 21.1N 113.3W  115 KT 130 MPH
 96H  28/1200Z 24.4N 113.3W  100 KT 115 MPH
120H  29/1200Z 27.0N 111.1W   75 KT  85 MPH...GULF OF CALIFORNIA
 
$$
Forecaster Beven