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Tropical Storm Rachel Discussion Number 4
NWS National Hurricane Center Miami FL EP182026
900 PM CST Sun Sep 27 2026
The last few visible satellite images of the day indicate that
Rachel continues to have a broad center. A recently received
Oceansat-3 scatterometer pass that partially sampled the system a
few hours ago indicated winds to at least 35 kt about 120 n mi west
of the center. Objective satellite intensity estimates range from
35-40 kt and the Dvorak classification from TAFB is T2.5/35 kt.
Based on these data, and the broad structure of the tropical
cyclone, the initial intensity is maintained at 35 kt for this
advisory.
Rachel is moving westward at 280/6 kt. The overall track philosophy
has not changed for this forecast. A deep-layer ridge building over
Mexico is expected to steer the cyclone west-northwestward at a
faster forward speed through mid-week. On Thursday, a weakness in
the ridge, caused by a trough over the southwestern United States,
will cause the cyclone to move more slowly on a similar
northwestward heading. The new track forecast is similar to the
advisory, and blends the Google DeepMind (GDM) and HFIP Corrected
Consensus Aid (HCCA).
The tropical storm continues to endure approximately 20 kt of
northeasterly shear, which is clearly evident on satellite imagery.
Given the broad structure and moderate to high wind shear, gradual
intensification is forecast over the next couple of days. The shear
is expected to subside early next week and intensification is likely
to continue thereafter, with Rachel forecast to become a hurricane
on Tuesday. Rachel could then track over the cool wake from
Hurricane Polo, though recent drifter data captured vertical
profiles that show high ocean heat content (OHC) persists in the
region. The intensity forecast is on the higher end of the guidance
envelope, and blends the GDM and HCCA solutions.
The analyzed and forecast tropical storm force wind radii for Rachel
are larger in this forecast than the previous one. Due to the
proximity of tropical storm force winds to the coast, the government
of Mexico has issue a Tropical Storm Watch from Punta San Telmo to
Playa Perula.
Key Messages:
1. Although the core of Rachel is forecast to remain offshore of
Mexico, tropical storm force winds are possible along a portion of
the coast of southwestern Mexico in the Tropical Storm Watch area
on Tuesday.
2. 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 28/0300Z 12.9N 99.8W 35 KT 40 MPH
12H 28/1200Z 13.3N 100.9W 45 KT 50 MPH
24H 29/0000Z 14.2N 102.6W 55 KT 65 MPH
36H 29/1200Z 15.2N 104.3W 60 KT 70 MPH
48H 30/0000Z 16.4N 106.0W 70 KT 80 MPH
60H 30/1200Z 17.5N 107.2W 80 KT 90 MPH
72H 01/0000Z 18.4N 108.2W 85 KT 100 MPH
96H 02/0000Z 19.1N 109.0W 85 KT 100 MPH
120H 03/0000Z 20.0N 109.7W 85 KT 100 MPH
$$
Forecaster Mahoney
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