Tropical Storm Ileana Forecast Discussion

960 
WTPZ44 KNHC 131435
TCDEP4

Tropical Storm Ileana Discussion Number   5
NWS National Hurricane Center Miami FL       EP092024
800 AM MST Fri Sep 13 2024

Recent satellite imagery shows that Ileana is producing a large
convective canopy with clouds top temperatures as cold as -80C.
However, data from the Mexican radar at Cabo San Lucas shows that
the convective banding under the canopy is poorly organized and
suggests that the circulation center is still broad and elongated.
The various satellite intensity estimates are little changed since
the previous advisory, so the initial intensity remains 40 kt.

The initial motion is 335/8 kt. This general motion should continue 
for the next 12 h or so, bringing the center across the southern 
portion of the Baja California peninsula later today and into the 
southern Gulf of California by early Saturday.  After that, a slower 
northward to north-northwestward motion is forecast until the 
cyclone dissipates over the weekend.  There are no significant 
changes to either the track forecast guidance and the forecast 
track.

Ileana currently appears too disorganized to take advantage of the 
current environment of light to moderate shear, good moisture, and 
warm water. Thus, little change in strength is expected before 
landfall in Baja California Sur.  When the cyclone reaches the Gulf 
of California, it is forecast to move into increasing westerly shear 
and a drier airmass, which should cause weakening despite the very 
warm sea surface temperatures.  Based on this scenario and the 
intensity guidance, the intensity forecast continues to show 
weakening, with the cyclone forecast to become a remnant low by 48 h 
and dissipate by 72 hr.


Key Messages:

1. Tropical Storm Ileana will bring heavy rainfall to portions of 
western Mexico and southern Baja California 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 to begin in portions of
Baja California Sur during the next several hours where Tropical 
Storm Warnings are in effect.


FORECAST POSITIONS AND MAX WINDS

INIT  13/1500Z 22.3N 109.3W   40 KT  45 MPH
 12H  14/0000Z 23.5N 109.7W   40 KT  45 MPH...INLAND
 24H  14/1200Z 24.8N 109.9W   35 KT  40 MPH...OVER WATER
 36H  15/0000Z 25.8N 110.2W   35 KT  40 MPH
 48H  15/1200Z 26.7N 110.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  16/0000Z 27.6N 111.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  16/1200Z...DISSIPATED

$$
Forecaster Beven