Advisories

000
WTPZ42 KNHC 250856
TCDEP2
 
Hurricane Polo Discussion Number  19
NWS National Hurricane Center Miami FL       EP172026
200 AM MST Fri Sep 25 2026

Since the previous advisory, Polo's eyewall and core cloud-top 
temperatures have cooled with a very wide and complete ring of 
cloud-top temperatures below -70C surrounding the eye, with a 
growing area of cloud-top temperatures colder than -75C surrounding 
most of the eye.  In addition, GOES-18 infrared eye temperatures 
have warmed significantly since the previous advisory, recently 
measured near 19C.  The latest TAFB Dvorak number is 7.0/140 kt, 
while DMINT and SATCON have been hovering around 135-136 kt.  Based 
on the improved structure, Polo is assigned an initial intensity of 
140 kt for this advisory, making it a category 5 hurricane again.

The initial motion is westward, or 275 degrees at 10 kt, so this 
motion continues to take the hurricane farther away from mainland 
western Mexico.  There is little change to the track forecast 
philosophy from the previous advisory.  Polo is currently being 
steered by the flow on the south side of a well-defined 
mid-tropospheric ridge that is building westward over northern 
Mexico.  This steering regime should continue through today.  After 
that, a mid-latitude trough moving eastward across the northeastern 
Pacific should prevent the ridge from building farther west, with 
Polo is expected to recurve northward and northeastward around the 
western periphery of the ridge.  The track guidance is generally in 
agreement on this scenario, although there are still notable 
differences in forward speed among the models in the 3-5 day time 
frame.  The official forecast is similar to the previous one through 
72 hours, but is faster toward the northeast at day 4-5 compared to 
the previous forecast.  The NHC forecast is slightly to the left of 
the HCCA and Google DeepMind Ensemble Mean through 96 hours, but is 
to the right of the simple consensus TVCN.  Confidence is high that 
Polo will make landfall in Baja California Sur and then mainland 
Mexico, after moving through the Gulf of California.
 
Polo will continue to move over very warm waters and in a low 
vertical wind shear environment through today.  Fluctuations in 
intensity are possible through today.  By Saturday, a gradual 
weakening trend is expected to begin due to some increase in shear.  
The official intensity forecast is on the high side of the model 
guidance, and shows the system still near major hurricane strength 
while it approaches the Baja California peninsula.  Rapid weakening 
is expected when the cyclone crosses the peninsula and moves into 
mainland Mexico due to land interaction and a further increase in 
vertical wind shear.
 
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. 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  25/0900Z 17.2N 107.5W  140 KT 160 MPH
 12H  25/1800Z 17.3N 108.9W  140 KT 160 MPH
 24H  26/0600Z 17.6N 110.7W  130 KT 150 MPH
 36H  26/1800Z 18.5N 112.2W  120 KT 140 MPH
 48H  27/0600Z 20.0N 113.2W  110 KT 125 MPH
 60H  27/1800Z 21.7N 113.7W  100 KT 115 MPH
 72H  28/0600Z 23.3N 113.5W   95 KT 110 MPH
 96H  29/0600Z 26.4N 111.2W   80 KT  90 MPH
120H  30/0600Z 29.0N 107.5W   30 KT  35 MPH
 
$$
Forecaster Hagen