Tropical Storm Ileana Forecast Discussion

401 
WTPZ44 KNHC 141438
TCDEP4

Tropical Storm Ileana Discussion Number   9
NWS National Hurricane Center Miami FL       EP092024
800 AM MST Sat Sep 14 2024

Satellite imagery shows that Ileana is being affected by increasing
southwesterly shear.  A large burst of convection that occurred in
the early morning hours has moved northeast of the exposed
low-level center, while new convection is forming to the north and
southeast of the center. The initial intensity is held at 35 kt
based on various satellite intensity estimates and earlier surface
data from Topolobampo, Mexico.

The initial motion is just east of due north or 010/6 kt.  This
general motion should continue for the next 6 hours or so, bringing 
the center near or over the coast of Mexico near Topolobampo and Los
Mochis today.  After that, Ileana should begin a slow motion toward
the northwest over the Gulf of California roughly parallel to the
coast of Mexico, with this motion continuing until the system
dissipates.  The new track forecast is nudged to the north and east
of the previous track and lies near the various consensus models.

Ileana is expected to weaken below tropical-storm strength later
today due to a combination of shear and land interaction.  However,
before that happens, the cyclone should bring tropical storm
conditions to portions of the northern coast of Sinaloa and
southern coast of Sonora through this afternoon.  The system is
expected to degenerate to a remnant low between 12-24 h, with the
remnant low dissipating over the central Gulf of California on
Monday.


Key Messages:

1. Tropical Storm Ileana will bring heavy rainfall to portions of
coastal Sinaloa, Mexico through this weekend. This heavy rainfall
will bring a risk of flash flooding and mudslides to portions of the
area.

2. Tropical storm conditions are expected within the warning area
of northern Sinaloa and southern Sonora through this afternoon.


FORECAST POSITIONS AND MAX WINDS

INIT  14/1500Z 24.9N 108.9W   35 KT  40 MPH
 12H  15/0000Z 25.6N 109.2W   30 KT  35 MPH...NEAR COAST
 24H  15/1200Z 26.3N 109.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  16/0000Z 26.9N 110.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  16/1200Z 27.7N 111.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 60H  17/0000Z...DISSIPATED

$$
Forecaster Beven