Tropical Storm Ileana Forecast Discussion

000
WTPZ44 KNHC 130233
TCDEP4

Tropical Storm Ileana Discussion Number   3
NWS National Hurricane Center Miami FL       EP092024
800 PM MST Thu Sep 12 2024

Ileana continues to slowly gain strength.  Deep convection has been
increasing near the center and in some fragmented curved bands
around the central dense overcast.  The latest objective and
subjective satellite intensity estimates range from 35 to 45 kt,
and based on that data, the initial wind speed is nudged upward to
40 kt.  Some of the outer bands are moving across west-central
Mexico and nearing the southern tip of the Baja California
peninsula.

The storm is moving north-northwestward at 10 kt toward a weakness
in the subtropical ridge.  A north-northwestward to northward motion
but at a slower pace is expected during the next few days, taking
Ileana across the southern portion of the Baja California peninsula
on Friday and into the Gulf of California this weekend.  The NHC
track forecast is similar to the previous one and near the HCCA and
TVCE aids.

Some additional strengthening is possible before Ileana reaches
Baja California and most of the models show the storm peaking in
intensity in about 12 hours.  Around the time the cyclone makes
landfall in Baja, a pronounced increase in wind shear and
intrusions of dry air, along with land interaction, should cause
steady weakening.  The shear is expected to increase to near 30 kt
in a couple of days, and that should cause Ileana to degenerate to
a remnant low by 60 hours and dissipate in 3 to 4 days.  The NHC
intensity forecast is in good agreement with the majority of the
models.

Key Messages:

1. Ileana will bring heavy rainfall to portions of western Mexico
and southern Baja California through the weekend. This heavy
rainfall will bring a risk of flash flooding and mudslides to
portions of the area.

2. Tropical storm conditions are expected to begin in portions of
the Baja California Sur on Friday, where Tropical Storm Warnings
are in effect.


FORECAST POSITIONS AND MAX WINDS

INIT  13/0300Z 21.0N 108.5W   40 KT  45 MPH
 12H  13/1200Z 22.3N 109.3W   45 KT  50 MPH
 24H  14/0000Z 23.7N 109.9W   40 KT  45 MPH...INLAND
 36H  14/1200Z 25.0N 110.1W   40 KT  45 MPH...OVER WATER
 48H  15/0000Z 26.1N 110.2W   35 KT  40 MPH
 60H  15/1200Z 27.0N 110.6W   30 KT  35 MPH...POST-TROPICAL
 72H  16/0000Z 27.9N 111.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  17/0000Z...DISSIPATED

$$
Forecaster Cangialosi