Advisories

000
WTPZ43 KNHC 291452
TCDEP3
 
Tropical Storm Rachel Discussion Number  10
NWS National Hurricane Center Miami FL       EP182026
900 AM CST Tue Sep 29 2026
 
Rachel is dealing with around 20 kt of northeasterly wind shear this 
morning, with the estimated center position located along the far 
northern edge of the central dense overcast. However, a burst of 
deep convection, with cloud top temperatures of around -90 C, along 
with strong upper-level outflow suggests that the system is slowly 
intensifying. The latest TAFB Dvorak intensity estimate was 3.5/55 
kt, while recent objective intensity estimates from UW-CIMSS range 
from 43-55 kt. Given the deepening convection and the slight 
increase in intensity estimates, the initial intensity is set at 55 
kt for this advisory. 
 
The strong tropical storm is moving toward the west-northwest around 
11 kt, steered by a strong mid-level ridge centered over the 
south-central United States. A turn toward the northwest is expected 
later today as high pressure builds over eastern Mexico, followed by 
a gradual decrease in forward speed as Rachel moves into a region 
with weaker steering flow. By late week, building high pressure to 
the northwest of the cyclone should induce a gradual turn back 
toward the west-northwest and then west, accompanied by a slight 
increase in forward speed. The updated forecast track is very 
similar to the previous advisory, remaining near the middle of the 
track forecast guidance envelope through 48 h and near the northern 
end of the guidance thereafter. 
 
Decreasing wind shear, sufficiently warm sea surface temperatures 
and favorable upper-level divergence are expected to support 
strengthening over the next couple of days, and Rachel is forecast 
to become a hurricane later today. However, Rachel could briefly 
move over slightly cooler waters left in the wake of Hurricane Polo 
tonight into early Wednesday, which may temporarily limit the rate 
of intensification. Thereafter, warmer waters should support 
additional strengthening through late this week. The latest NHC 
intensity forecast is near the upper-end of the guidance envelope, 
although it remains slightly below the HCCA solution. 
 
 
Key Messages:
 
1. Although the core of Rachel is forecast to remain offshore of 
Mexico, tropical-storm-force winds are expected along a portion of 
the coast of southwestern Mexico in the Tropical Storm Warning area 
today or tonight. Tropical storm conditions are possible in the 
watch area tonight or on Wednesday.
 
2. Outer bands from Rachel will bring locally heavy rainfall to
portions of coastal southwest Mexico through Thursday. This rainfall
may produce areas of flooding and mudslides, especially in regions
of steep terrain.
 
3. Large waves could produce life-threatening surf and rip current
conditions along portions of the southwestern coast of Mexico during
the next several days.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  29/1500Z 15.3N 105.0W   55 KT  65 MPH
 12H  30/0000Z 16.5N 106.4W   65 KT  75 MPH
 24H  30/1200Z 17.9N 107.7W   75 KT  85 MPH
 36H  01/0000Z 19.0N 108.8W   85 KT 100 MPH
 48H  01/1200Z 19.7N 109.5W   90 KT 105 MPH
 60H  02/0000Z 20.1N 110.0W   90 KT 105 MPH
 72H  02/1200Z 20.4N 110.6W   95 KT 110 MPH
 96H  03/1200Z 20.8N 112.1W   90 KT 105 MPH
120H  04/1200Z 21.1N 114.0W   85 KT 100 MPH
 
$$
Forecaster Adams