645 
WTPZ42 KNHC 251450
TCDEP2
 
Hurricane Polo Discussion Number  20
NWS National Hurricane Center Miami FL       EP172026
800 AM MST Fri Sep 25 2026
 
After regaining Category 5 status overnight, the remarkable
satellite presentation of Polo indicates the hurricane has continued
to intensify. The eye has contracted and warmed over the past
several hours, with temperatures above 20 deg C measured inside the
eye. A thick, solid ring of deep convection surrounds the center,
with cloud tops as cold as -80 to -85 deg C. There were no
indications of a concentric eyewall structure in 0905 UTC AMSR3
passive microwave imagery. The latest UW-CIMSS ADT estimates and a
T7.5 Dvorak classification from TAFB support an initial intensity of
155 kt. A NOAA research aircraft mission is scheduled to investigate
Polo later today.
 
Polo continues moving westward (270/10 kt) along the south side of a
mid-level ridge that extends across northern Mexico. This weekend, a
deep-layer trough approaching from the west is expected to erode the
steering ridge. This will cause Polo to turn northwestward and
northward as it moves around the western side of the ridge. By
Monday, the increasing influence of the upper trough should turn
Polo northeastward toward Baja California Sur and west-central
Mexico. The global models and AI-based guidance are generally
in good agreement on this track evolution. The updated NHC track
forecast is adjusted slightly to the left of the previous one, and
is also a bit slower to come into better agreement with the latest
multi-model consensus. Overall, the NHC forecast remains on the
faster and right side of the envelope, closer to HCCA and GDMI.
Based on this prediction, watches could be required for portions of
the Baja California Peninsula as early as Saturday.
 
Based on the aforementioned AMSR3 data, an eyewall replacement cycle
(ERC) does not appear imminent. Thus, further slight strengthening
cannot be ruled out while Polo remains over very warm waters in a
weaker shear environment. The vertical wind shear is expected to
increase over the weekend, and because of this as well as the
possibility of a future ERC, the NHC intensity forecast shows a
weakening trend beginning on Saturday and continuing into next week.
Regardless, Polo is predicted to approach Baja California Sur as a
strong hurricane early next week, and interests there should closely
monitor the latest forecast updates. The NHC forecast remains on the
higher side of the intensity guidance, generally following HCCA.
Once land interaction occurs with the Baja California Peninsula and
mainland Mexico, more rapid weakening is anticipated.
 
Distant moisture from Hurricane Polo and Odalys will be transported
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. 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. Watches could be required as early as Saturday for
portions of the area.
 
2. Heavy rainfall associated with Polo may begin to impact Baja
California Sur late Sunday into Monday. This rainfall may produce
life-threatening flooding and mudslides, especially in areas of
steep terrain.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/1500Z 17.1N 108.5W  155 KT 180 MPH
 12H  26/0000Z 17.2N 109.8W  155 KT 180 MPH
 24H  26/1200Z 17.8N 111.5W  140 KT 160 MPH
 36H  27/0000Z 18.9N 112.7W  125 KT 145 MPH
 48H  27/1200Z 20.4N 113.4W  110 KT 125 MPH
 60H  28/0000Z 22.0N 113.7W  100 KT 115 MPH
 72H  28/1200Z 23.8N 113.4W   95 KT 110 MPH
 96H  29/1200Z 26.9N 110.8W   70 KT  80 MPH
120H  30/1200Z 30.4N 106.5W   30 KT  35 MPH...POST-TROP/INLAND
 
$$
Forecaster Reinhart