Advisories

000
WTPZ42 KNHC 262034
TCDEP2
 
Hurricane Polo Discussion Number  25
NWS National Hurricane Center Miami FL       EP172026
200 PM MST Sat Sep 26 2026
 
SAR data valid this morning that arrived after the issuance of the 
last advisory indicated that Polo's inner-core has expanded, 
possibly due to an eyewall replacement cycle. A combination of a 
slight increase in easterly wind shear over the past 12 hours  
(10-15 kt according to both SHIPS diagnostics and UW-CIMSS 
analysis) and the likely eyewall replacement cycle are likely 
causing Polo to weaken. Intensity estimates vary greatly, from a 105 
kt estimate with that SAR pass to over 140 kt from the ADT. Taking 
the available data as a whole, the intensity is set at 125 kt for 
this advisory, which is also fairly close to recent estimates from 
of the newer techniques from UW-CIMSS: AiDT, DPRINT and DMINT. A 
NOAA Hurricane Hunter aircraft is scheduled to investigate Polo 
later today, which should provide more information about the 
structure and intensity of the hurricane.
 
The hurricane has turned northwestward as it moves around the
western end of a mid-level ridge centered over northern Mexico.
Polo will gradually turn northward, and then northeastward over
the next two days as it continues to move around the ridge and is
steered increasingly by a mid- to upper-level trough approaching
from the northwest. There is an unusually large spread in the track
models, primarily associated with Polo's forward speed. The AI
guidance, including GDM, show a notably faster forward motion than
many of the dynamical models, with some of the hurricane regional
models even forecasting the hurricane to stall offshore of the west
coast of the Baja California peninsula. No changes of note were made
to the track forecast with this advisory and the NHC forecast still
leans toward the AI models and HCCA, but confidence in that forecast
is not particularly high due to the high model spread.
 
The models have better agreement on the intensity forecast and 
nearly unanimously depict Polo steadily weakening over the next 48 
hours. Some short-term intensity fluctuations will be possible 
during that period, but a combination of moderate shear and a drier 
environment along the forecast track should prevent it from 
significantly restrengthening. It is worth noting that Polo is still 
expected to be a strong hurricane when it approaches Baja California 
Sur. More rapid weakening is likely beyond 60 hours, as the shear is 
expected to increase substantially and Polo is forecast to begin 
interacting with land.
 
Polo is expected to become a remnant low and then dissipate before
it reaches the southern U.S., but distant moisture associated with
it and Odalys will be transported into the southwestern United
States late 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 west coast of the Baja
California peninsula on Monday as a hurricane, and a Hurricane
Watch is in effect for that region. Tropical storm conditions
could reach portions of the coast as soon as Sunday night or early
Monday, making further preparations difficult. A storm surge will
be possible, especially in areas of onshore winds.
 
2. Heavy rainfall associated with Polo may begin to impact Baja 
California Sur Sunday night into Tuesday. This rainfall may produce 
life-threatening flooding and mudslides, especially in areas of 
steep terrain.
 
3. Dangerous surf and rip currents are likely along portions of
the northwest coast of Mexico and Baja California for the next
several days.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/2100Z 18.7N 112.5W  125 KT 145 MPH
 12H  27/0600Z 19.8N 113.4W  115 KT 130 MPH
 24H  27/1800Z 21.4N 114.0W  105 KT 120 MPH
 36H  28/0600Z 23.2N 114.0W   95 KT 110 MPH
 48H  28/1800Z 24.8N 113.3W   85 KT 100 MPH
 60H  29/0600Z 26.4N 111.9W   70 KT  80 MPH...INLAND
 72H  29/1800Z 28.0N 110.2W   50 KT  60 MPH...INLAND
 96H  30/1800Z 31.2N 105.7W   20 KT  25 MPH...POST-TROP/INLAND
120H  01/1800Z...DISSIPATED
 
$$
Forecaster D. Zelinsky