042
WTPZ42 KNHC 282052
TCDEP2

Hurricane Polo Discussion Number  33
NWS National Hurricane Center Miami FL       EP172026
200 PM MST Mon Sep 28 2026

NOAA Hurricane Hunters investigated Polo this afternoon, finding the
hurricane was still well organized with a 23 n mi wide eye, though
the eyewall was open to the southwest and there was a subtle
increase in the vertical tilt comparing the 1-5 km Tail Doppler
Radar (TDR) wind data from the aircraft. The highest 700 mb
flight-level winds were 106 kt in the southeast quadrant, which
using a typical 0.9 reduction factor would suggest an intensity of
95 kt. However, the TDR data has also been useful to diagnose the
intensity of Polo since it samples a larger wind field swath, and
the final southwest to northeast leg through the hurricane indicated
0.5 km winds up to 112 kt in the northeast eyewall. Experimental
reduction data from this TDR analysis in this region reduced these
boundary layer winds down to 100 kt at 10 meters. Thus, the initial
intensity remains 100 kt for this advisory.

Polo continues to move northeastward, but it is starting to
accelerate some with an current motion of 40 degrees at 10 kt. This
general motion should continue over the next day with gradual
acceleration as the hurricane is captured by a strong shortwave
trough swinging into the southwestern United States. This track will
take Polo`s core over the Baja California Peninsula this evening
very close to Puerto San Andresito. The hurricane will then briefly
move over the Gulf of California overnight, finally making a second
landfall in northwestern mainland Mexico on Tuesday morning. The NHC
track forecast is essentially an update from this morning, and is in
the middle of the tightly clustered guidance.

Sea-surface temperatures actually increase a bit as Polo approaches
Baja California Sur. Vertical wind shear, while also increasing, is
unlikely to get strong enough over the next 3-6 h to cause much
weakening. Thus, Polo is likely to maintain its current intensity
and be at or near major hurricane intensity when it makes landfall
on the west coast of Baja California Sur this evening. Weakening
will likely begin immediately after it moves over the rugged terrain
of the peninsula, though Polo is still expected to be a hurricane
when it makes its second landfall in mainland Mexico on the Gulf of
California coast. Rapid weakening is expected when Polo moves fully
inland over the high rugged terrain of northwestern Mexico, and the
tropical cyclone is expected to degenerate into a trough  before its
remnants reach the southwestern United States.

However Polo`s remnant vorticity will ultimately interact and phase
with a strong cutoff low digging into the the four corners region of
the U.S. on Tuesday into Wednesday, contributing to heavy rainfall,
flash flooding, and gusty winds 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 to make landfall on the west coast of the Baja
California Peninsula near major hurricane strength this evening.
Conditions will deteriorate quickly, and residents are urged to seek
safe shelter.  Hurricane and tropical storm conditions will spread
inland across Baja California tonight, and 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 today into
Tuesday. This rainfall may 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 late today 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 and 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  28/2100Z 25.0N 113.0W  100 KT 115 MPH
 12H  29/0600Z 26.2N 112.1W   80 KT  90 MPH...INLAND OVER BAJA CA
 24H  29/1800Z 28.7N 109.8W   40 KT  45 MPH...INLAND OVER MEXICO
 36H  30/0600Z...DISSIPATED

$$
Forecaster Papin