Hurricane Vance

000
WTPZ42 KNHC 250245
TCDEP2
 
Hurricane Vance Discussion Number  15
NWS National Hurricane Center Miami FL       EP222026
900 PM CST Sat Oct 24 2026
 
Vance continues to look disorganized on satellite images, and it 
seems that southwesterly shear is keeping the convection displaced 
from the center. The hurricane is also moving over cool waters, 
which is also inhibiting intensification as well. GPM microwave 
images show that the structure of the cyclone is vertically tilted 
due to the aforementioned shear. Despite the system's ragged 
appearance, the Dvorak intensity estimate from TAFB is still 
T5.0/90 kt while the objective intensity estimates are in the range 
of 68-81 kt. Therefore, the initial intensity has been kept to 80 kt 
based on a combination of that data, however, it could be generous. 
 
The intensity forecast still has plenty of uncertainties. Vance is 
generally expected to weaken during the next 12 h due to the 
continuous of shear while it remains over cool SSTs. After that 
time, the hurricane's intensity could fluctuate when Vance moves 
over warmer waters, but the wind shear will likely remain elevated. 
After 48 h, the wind shear is expected to increase even further and 
that should result in a gradual weakening trend. It is possible 
that Vance could weaken more than forecast given the expected 
increasing shear and intrusions of dry air. The NHC intensity 
forecast is generally similar to the previous one with only a few 
minor adjustments made. 
 
The initial motion remains slowly north-northwestward or 340/4 kt. 
The cyclone is currently being steered by a weak low- to mid-level 
ridge over eastern Mexico, and it is moving toward a large 
mid-latitude trough over the western United States and northwestern 
Mexico. Vance should move into an area where the steering currents 
are light, thus the hurricane is expected to move even slower over 
the next few days. The latest guidance shifted significantly to the 
west compared to the previous forecast, including the highly skilled 
forecast aids HCCA and GDMI, which has added some uncertainty in the 
track forecast. The new track forecast was adjusted slightly to the 
west and is a little slower than the previous one. However, the 
current track is on the eastern side of the guidance envelope, and 
additional adjustments to the west could be needed. 
 
Key Messages:
 
1. Due to the uncertainties in both the track and intensity
forecasts, it is too early to say what wind and storm surge
impacts Vance may cause along the coast of Mexico. Interests in
southwestern Mexico should continue to monitor the progress of the
hurricane.
 
2. Heavy rainfall associated with slow-moving Hurricane Vance will
impact the western coast of Mexico from Michoacán to Jalisco during
much of next week. This rainfall may produce life-threatening
flooding and mudslides across Colima and western portions of
Michoacán and Jalisco, especially in areas along steep terrain.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/0300Z 13.7N 103.4W   80 KT  90 MPH
 12H  25/1200Z 14.2N 103.7W   70 KT  80 MPH
 24H  26/0000Z 15.1N 104.2W   70 KT  80 MPH
 36H  26/1200Z 15.6N 104.6W   70 KT  80 MPH
 48H  27/0000Z 16.1N 104.8W   70 KT  80 MPH
 60H  27/1200Z 16.5N 105.0W   65 KT  75 MPH
 72H  28/0000Z 17.3N 105.2W   55 KT  65 MPH
 96H  29/0000Z 18.4N 105.6W   45 KT  50 MPH
120H  30/0000Z 19.6N 106.1W   35 KT  40 MPH
 
$$
Forecaster Katz/Cangialosi