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Tropical Storm Ileana Discussion Number 6
NWS National Hurricane Center Miami FL EP092024
200 PM MST Fri Sep 13 2024
Satellite imagery and radar data from Cabo San Lucas indicate that
Ileana remains poorly organized with poorly-defined convective
banding around the elongated center. The latest satellite and radar
imagery suggests the center is just east of the latest burst of
convection south of Cabo San Lucas, and this is in reasonable
agreement with positions from recently received ASCAT data. The
scatterometer passes show 30-35 kt winds to the east of the center,
and based on this and the possibility of undersampling, the initial
intensity is held at a possibly generous 40 kt.
The scatterometer and and an earlier microwave image show that
Ileana is moving slower than thought previously, and the initial
motion is now 345/6. A slow north-northwestward to northward motion
should continue until the cyclone dissipates, with the center
passing near or over the southern end of the Baja California
peninsula during the next 6-12 h and then moving over the central
and southern Gulf of California. The track guidance shifted a
little to the east of the previous guidance, and the new forecast
track is a little to the east of the previous track.
The cyclone should be moving into an environment of increasing
southwesterly to westerly shear and a drier airmass as it moves
into the Gulf of California. The intensity guidance is in good
agreement that Ileana should weaken, and the new intensity forecast
follows this trend. The forecast now calls for the system to become
a depression by 36 h, a remnant low by 48 h, and dissipate by 72 h.
It is possible that Ileana could decay to a remnant low by 36 h, as
the GFS and ECMWF forecast the associated convection to dissipate by
that time.
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 13/2100Z 22.7N 109.4W 40 KT 45 MPH
12H 14/0600Z 23.7N 109.5W 40 KT 45 MPH
24H 14/1800Z 24.9N 109.6W 35 KT 40 MPH
36H 15/0600Z 25.8N 110.0W 30 KT 35 MPH
48H 15/1800Z 26.6N 110.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 16/0600Z 27.5N 111.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 16/1800Z...DISSIPATED
$$
Forecaster Beven
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