Tropical Cyclone Discussion

642
WTPZ42 KNHC 290234
TCDEP2
 
Hurricane Polo Discussion Number  34
NWS National Hurricane Center Miami FL       EP172026
800 PM MST Mon Sep 28 2026
 
Polo is about to make landfall on Baja California Sur. Heavy rains
and hurricane-force winds have already spread across the peninsula,
and the worst conditions will likely occur in the hurricane warning
area within the next few hours. Polo is not as well organized as it
was earlier, with the eye filling in satellite images. The initial
intensity is held at 100 kt near the high end of the latest
satellite estimates, but this could be a little generous.
 
The hurricane is moving northeastward at 11 kt, and that motion
with an increase in forward speed is expected as a mid- to
upper-level trough amplifies over the southwestern U.S. This
track should take the system across Baja California and the Gulf
of California tonight and then inland over the Mexican state of
Sonora Tuesday morning. Little change was made to the previous
track forecast, and this one remains near the middle of the
guidance envelope.
 
Little change in strength is expected before Polo makes landfall on
Baja California Sur. However, the combination of land interaction
and increasing vertical wind shear should cause Polo to rapidly
weaken overnight, but it is still expected to be a hurricane when it
makes its second landfall in Sonora Tuesday morning. Polo should
quickly dissipate over the rugged terrain of Mexico later on
Tuesday, and even though a 24-hour position is provided, it seems
unlikely that the hurricane will still be around by then.
 
Polo's remnant vorticity will likely interact and phase with a
strong cutoff low digging into the Four Corners region of the U.S.
on Tuesday and Wednesday, contributing to heavy rainfall, flash
flooding, and gusty winds in the southwestern U.S. and southern
Plains. See products issued by the Weather Prediction Center and
local National Weather Service offices for more information.
 
 
Key Messages:
 
1. Polo is forecast about to make landfall as a major hurricane on
the west coast of the Baja California Peninsula. Residents should
remain in a safe shelter. Hurricane and tropical storm conditions
will spread into mainland Mexico late tonight and early Tuesday. A
dangerous storm surge is expected in areas of onshore winds.
 
2. Heavy rainfall associated with Polo will impact Baja California
Sur along with southern and central portions of Sonora tonight and
Tuesday. This rainfall is expected to produce life-threatening
flooding and mudslides, especially in areas of steep terrain.
Moisture from Polo will support heavy rainfall and flooding
potential across the Southwest U.S. into the Southern High Plains
tonight into Tuesday.
 
3. Even after Polo dissipates, its mid-level remnants may produce
strong gusty winds well inland over the higher terrain of northwest
Mexico, southern New Mexico, and far western Texas.
 
4. Dangerous surf and rip currents are likely along portions of the
northwest coast of Mexico and Baja California for the next day or
so.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  29/0300Z 25.9N 112.5W  100 KT 115 MPH
 12H  29/1200Z 27.7N 110.9W   75 KT  85 MPH
 24H  30/0000Z 31.0N 107.7W   30 KT  35 MPH...POST-TROP/INLAND
 36H  30/1200Z...DISSIPATED