Hurricane Polo

981 
WTPZ42 KNHC 242051
TCDEP2
 
Hurricane Polo Discussion Number  17
NWS National Hurricane Center Miami FL       EP172026
300 PM CST Thu Sep 24 2026
 
A NOAA Hurricane Hunter aircraft has investigated Polo during the
past few hours, and its data indicates that the eyewall replacement
cycle mentioned in the previous advisory is almost complete. The 
first aircraft pass reported concentric eyewalls of 15 and 30 n mi 
diameters. Subsequent passes reported that the inner eyewall 
dissipated, while the remaining outer eyewall contracted to 25 n mi 
diameter. In addition, 700-mb flight level winds in the northeast 
eyewall increased by about 15 kt during the mission, with the 
maximum winds of 147 kt.  The central pressure also started to fall 
during the mission, and the estimated value from data on the last 
pass is near 935 mb. Based on these data, the initial intensity is 
set at 130 kt. It should be noted that the strengthening observed 
by the aircraft has not yet been fully reflected in satellite 
imagery.
 
Polo is now moving west-northwestward or 285/9 kt. There is little 
change to the track forecast reasoning from the previous advisory. 
A mid-level ridge building westward from northern Mexico should 
steer the hurricane generally westward for the next 24-36 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 is 
generally in good agreement with this scenario, although there 
remains some spread in the forward speed between the slower HAFS 
models and the faster GFS and HCCA models. The new track, which is 
an update of the previous forecast, takes the center away from the 
southwestern coast of Mexico this evening and then has it moving 
across Baja California into northwestern mainland Mexico in 96-120 
h.
 
The new intensity forecast now calls for Polo to strengthen for the
next 12 h or so after the end of the eyewall replacement, and Polo
is expected to regain Category 5 strength tonight or Friday
morning. After that, a slow weakening is expected through 96 h as
Polo encounters somewhat increased shear, with the caveat that
there could be some fluctuations due to additional eyewall
replacement cycles. Rapid weakening is expected when the cyclone
crosses Baja California and moves into mainland Mexico. The new
forecast again lies near the upper edge of the intensity guidance.

It should be noted that moisture from Hurricane Polo and Odalys 
will be carried a long distance into the southwestern United States 
this weekend and early next week, and may indirectly contribute to 
a heavy rainfall and flash flood threat in the region. See products 
issued by the Weather Prediction Center for more information.
 
 
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. Wind gusts to tropical storm force may occur along portions of 
the southwestern coast of Mexico this evening.
 
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  24/2100Z 17.1N 105.5W  130 KT 150 MPH
 12H  25/0600Z 17.2N 106.8W  140 KT 160 MPH
 24H  25/1800Z 17.4N 108.8W  135 KT 155 MPH
 36H  26/0600Z 17.8N 110.5W  130 KT 150 MPH
 48H  26/1800Z 18.7N 112.0W  125 KT 145 MPH
 60H  27/0600Z 20.3N 113.1W  120 KT 140 MPH
 72H  27/1800Z 22.0N 113.4W  110 KT 125 MPH
 96H  28/1800Z 25.2N 112.8W   95 KT 110 MPH
120H  29/1800Z 27.9N 109.9W   60 KT  70 MPH...INLAND
 
$$
Forecaster Beven