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Tropical Storm Ileana Discussion Number 8
NWS National Hurricane Center Miami FL EP092024
200 AM MST Sat Sep 14 2024
Ileana continues to produce bursts of deep convection, but a
sharpening of the west side of the cloud canopy suggests stronger
vertical shear is setting in. Maximum winds are still estimated to
be 35 kt based on ASCAT data from last evening, and the fact that
subjective and objective intensity estimates have not begun to
decrease much quite yet.
Ileana's center is moving northward over the southern Gulf of
California, away from southern Baja California Sur, with an initial
motion of 360/8 kt. A northward motion is expected to continue
today, bringing Ileana's center near or over the coast of northern
Sinaloa and southern Sonora around midday. The new NHC track
forecast is a bit to the east of the previous prediction during the
first 12 hours or so, mainly due to an adjustment of the initial
position. The track guidance indicates that Ileana should slow
down and turn north-northwestward and then northwestward tonight
and on Sunday, generally running up the length of the Gulf of
California.
Although deep-layer shear is beginning to increase, several models,
including the GFS and ECMWF, indicate that Ileana could maintain
tropical storm intensity and bring tropical storm conditions to
portions of the northern coast of Sinaloa and southern coast of
Sonora later this morning and early afternoon. These same models,
however, show Ileana's convection quickly being sheared away and
dissipating by this evening and tonight as the cyclone moves into a
much drier air mass. As a result, the NHC forecast shows Ileana
degenerating into a remnant low in about 24 hours, with the remnant
low dissipating over the central Gulf of California by early Monday.
Key Messages:
1. Tropical Storm Ileana will bring heavy rainfall to portions of
western 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 later this morning and
afternoon.
FORECAST POSITIONS AND MAX WINDS
INIT 14/0900Z 24.3N 109.2W 35 KT 40 MPH
12H 14/1800Z 25.1N 109.3W 35 KT 40 MPH
24H 15/0600Z 25.9N 109.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 15/1800Z 26.6N 110.4W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 16/0600Z 27.4N 111.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
60H 16/1800Z...DISSIPATED
$$
Forecaster Berg
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