545 
WTPZ41 KNHC 301439
TCDEP1
 
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