277
WTPZ43 KNHC 010235
TCDEP3

Hurricane Rachel Discussion Number  16
NWS National Hurricane Center Miami FL       EP182026
800 PM MST Wed Sep 30 2026

Satellite imagery indicates that Rachel`s convective structure has
changed little over the past several hours. Deep convection
continues to burst near the center, with cloud-top temperatures as
cold as -85 C. The latest subjective Dvorak intensity estimate from
TAFB is T4.5/77 kt, while objective estimates have ranged from 65 to
85 kt. Given these estimates and the persistent deep convection,
the initial intensity is increased to 80 kt.

Rachel continues to move northwestward, or 320/6 kt. A northwestward
motion at a slower forward speed is expected during the next day or
so as the cyclone moves along the southwestern periphery of a
mid-level ridge while a mid- to upper-level trough remains over the
southwestern United States and northwestern Mexico. As the trough
lifts northeastward and weakens, a ridge is forecast to build north
of Rachel, causing the system to gradually turn west-northwestward
and then westward later this week. The track guidance remains in
good agreement on this overall scenario, and the latest NHC track
forecast is essentially an update of the previous prediction, lying
near the HCCA and GDMI aids.

Environmental conditions should remain generally favorable for
strengthening during the next couple of days, with very warm sea
surface temperatures and plenty of mid-level moisture along the
forecast track. Persistent easterly vertical wind shear of around 15
to 20 kt may be a limiting factor in the short term, but the shear
is forecast to gradually relax thereafter. Rachel could strengthen
rapidly by Thursday, especially if a more persistent inner core
becomes established, and is forecast to become a major hurricane
within the next couple of days. Thereafter, progressively cooler sea
surface temperatures and dry mid-level air should induce a gradual
weakening trend. The latest NHC intensity forecast is similar to the
previous advisory, lying above the guidance envelope in the short
term before trending toward the upper end of the guidance
thereafter.


Key Messages:

1. Although the core of Rachel is forecast to remain offshore of
Mexico, wind gusts of tropical-storm force are possible along
portions of the coast of southwestern Mexico through tonight.

2. Outer bands from Rachel will continue to produce locally heavy
rainfall across portions of coastal southwest Mexico. This rainfall
may produce life-threatening flooding and mudslides, especially in
areas of steep terrain.

3. Large waves could produce life-threatening surf and rip current
conditions along the southwestern and west-central coast of Mexico
and the southern Baja California Peninsula during the next several
days.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 19.2N 108.5W   80 KT  90 MPH
 12H  01/1200Z 19.6N 109.1W   90 KT 105 MPH
 24H  02/0000Z 19.8N 109.6W   95 KT 110 MPH
 36H  02/1200Z 20.0N 110.3W  105 KT 120 MPH
 48H  03/0000Z 20.1N 111.1W  105 KT 120 MPH
 60H  03/1200Z 20.2N 111.9W  100 KT 115 MPH
 72H  04/0000Z 20.4N 112.9W   90 KT 105 MPH
 96H  05/0000Z 20.7N 114.9W   85 KT 100 MPH
120H  06/0000Z 20.9N 118.0W   80 KT  90 MPH

$$
Forecaster Gibbs