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Tropical Storm Flossie Discussion Number 6
NWS National Hurricane Center Miami FL EP062025
900 AM CST Mon Jun 30 2025
Flossie continues to consolidate this morning with GOES-19 infrared
imagery showing deep convection bursting over the low-level center.
A SSMIS microwave pass from 1117 UTC this morning depicts the system
continues to become better organized, with curved banding and
potentially an inner core trying to develop. Latest Dvorak satellite
intensity estimates from TAFB and SAB have increased this advisory
to T/3.0. UW-CIMMS objective estimates range from 45 to 53 kt. Given
the improving structure and recent satellite trends, the initial
intensity is set to 50 kt for this advisory.
Environmental conditions are favorable for steady to rapid
intensification, with low vertical wind shear, plentiful moisture,
and warm SSTs. The latest NHC forecast explicitly forecasts rapid
intensification over the next 24 hours, and it is noted that some
SHIPS guidance shows a 50-65 percent chance of a 55kt increase in
the next 48 h. The NHC peak intensity forecast remains on the higher
end of the intensity guidance near the HCCA corrected consensus. In
about 48-60 hours, environmental conditions become increasingly less
favorable along the forecast track, with drier air and cooler sea
surface temperatures, which should induce a steady weakening trend.
By day 4, Flossie is forecast to become a post-tropical cyclone as
the system will struggle to produce convection within the harsh
environment.
The initial estimated motion is toward the northwest, or 310/9 kt.
A northwest to west-northwest motion is expected throughout the
forecast period, as Flossie is steered around the western periphery
of a mid-level ridge. The NHC track forecast near the previous and
lies closest to the HCCA corrected consensus aids.
Residents of Mexico should stay updated on the latest forecast. A
shift in track to the right of the official forecast could bring
more significant impacts to the coast of southwestern Mexico.
KEY MESSAGES:
1. The outer bands of Tropical Storm Flossie should bring locally
heavy rainfall to coastal portions of the Mexican states of
Guerrero, Michoacán, Colima, and Jalisco through Wednesday.
Life-threatening flooding and mudslides are possible, particularly
in steep terrain.
2. A tropical storm warning is in effect for a portion of
southwestern Mexico, where tropical storm conditions are expected
late today through Tuesday.
FORECAST POSITIONS AND MAX WINDS
INIT 30/1500Z 15.6N 102.6W 50 KT 60 MPH
12H 01/0000Z 16.5N 103.8W 60 KT 70 MPH
24H 01/1200Z 17.4N 105.4W 75 KT 85 MPH
36H 02/0000Z 18.2N 106.9W 80 KT 90 MPH
48H 02/1200Z 19.2N 108.2W 85 KT 100 MPH
60H 03/0000Z 20.0N 109.3W 75 KT 85 MPH
72H 03/1200Z 20.9N 110.4W 60 KT 70 MPH
96H 04/1200Z 23.0N 112.6W 40 KT 45 MPH...POST-TROPICAL
120H 05/1200Z 24.5N 114.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
$$
Forecaster Kelly/Nepaul
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