Advisories

000
WTPZ42 KNHC 212052
TCDEP2
 
Hurricane Polo Discussion Number   5
NWS National Hurricane Center Miami FL       EP172026
300 PM CST Mon Sep 21 2026
 
Satellite images show that Polo has a ragged eye on both visible
and infrared images, with very deep convection starting to wrap
around a broken eyewall.  The NOAA Hurricane Hunter aircraft has
been providing valuable data that show the cyclone undergoing an
early-stage eyewall cycle, with two wind maxes on the TDR radar.
The plane recently reported 0.5 km winds up to 92 kt, with
higher winds and lower central pressure on each fix, dropping about 
1 mb per hour.  These winds convert to roughly 75 kt at the 
surface, and that will be the initial wind speed this advisory.
 
While the current eyewall replacement could slightly hinder 
intensification, the last aircraft pass through Polo already showed 
that the old inner eyewall was fading.  Thus, given the very warm 
waters, light shear and moist environment, a high-end rapid 
intensification event is expected.  The latest model guidance are 
even higher than the last cycle, and the new NHC intensity forecast 
follows the trend, but is still below the NOAA HCCA corrected- 
consensus aid.  An increase in easterly wind shear could cause some 
weakening in the medium-range period, though Polo should be a small 
and powerful hurricane throughout the forecast period.
 
The storm is drifting east-southeastward and should move in that 
general direction for about a day before a mid-level ridge 
intensifies over Mexico.  This ridge should cause the cyclone to 
turn sharply towards the northwest and west-northwest on Wednesday 
and Thursday, bringing the core of the storm near or south of the 
coast of southwestern Mexico.  Eventually there is enough troughing 
over the eastern Pacific to cause the system to bend more 
northwestward at long range towards the Baja California peninsula.  
The details, however, are pretty sketchy with a potential binary 
interaction with Tropical Storm Odalys looming, which is helping to 
cause a large north-south spread in the guidance.  No big changes 
were made to the NHC forecast, but it is a little farther west at 
and beyond 72 hours where uncertainty is high.  
 
 
Key Messages:
 
1. Heavy rainfall associated with Polo will impact coastal portions 
of southwest Mexico through Thursday. This rainfall may produce 
life-threatening flooding and mudslides, especially in areas of 
steep terrain.
 
2. Polo is forecast to strengthen to a major hurricane while it
moves closer to the coast of southwestern Mexico during the next few
days. Although the core of the hurricane is forecast to stay
offshore, it is too soon to determine the exact location or
magnitude of impacts. Residents in southwestern Mexico should
closely monitor its progress and updates to the forecast. A Tropical
Storm Watch is in effect for portions of southwestern Mexico.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/2100Z 15.1N 102.7W   75 KT  85 MPH
 12H  22/0600Z 14.9N 102.3W  100 KT 115 MPH
 24H  22/1800Z 14.9N 102.0W  125 KT 145 MPH
 36H  23/0600Z 15.4N 102.2W  140 KT 160 MPH
 48H  23/1800Z 16.1N 102.9W  145 KT 165 MPH
 60H  24/0600Z 17.0N 104.0W  140 KT 160 MPH
 72H  24/1800Z 17.7N 105.5W  140 KT 160 MPH
 96H  25/1800Z 18.6N 108.6W  130 KT 150 MPH
120H  26/1800Z 20.5N 111.2W  120 KT 140 MPH
 
$$
Forecaster Blake