Hurricane ODILE

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HURRICANE ODILE DISCUSSION NUMBER  18
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP152014
800 AM PDT SUN SEP 14 2014

After rapidly strengthening during the past 24 hours, it appears
that the intensity of Odile has leveled off for now.  Microwave
images indicate that the cyclone has a double eyewall structure,
with the inner eyewall surrounding the 10-15 n mi diameter eye, and
the outer one located about 40-50 n mi from the center.  Satellite
intensity estimates remain 115 kt, and that value is kept for the
initial wind speed.  An Air Force reconnaissance aircraft is
scheduled to investigate Odile later today, and should provide a
better assessment of the strength and structure of this hurricane.

The major hurricane is moving northwestward at about 12 kt, steered
by a ridge located to its northeast.  A continued northwestward
motion is expected during the next 3 to 4 days with a gradual
decrease in forward speed due to a strengthening trough off the U.S.
west coast.  By the end of the forecast period, the shallow cyclone
is expected to become stationary or drift eastward in the low-level
flow.  The models are tightly clustered for most of the forecast
period, and the NHC track forecast is close to the consensus aids.
This track takes the center of Odile very near the southern Baja
California west coast later today, and then just offshore
and parallel to the coast for the next several days.

The observed concentric eyewall structure, which is fairly common
in mature hurricanes like Odile, typically causes intensity
fluctuations in the short term, and the NHC intensity forecast
shows little change in strength during the next 24 hours.  Odile
will be moving over cool water and into a drier airmass in 36 to 48
hours.  These unfavorable thermodynamic conditions should cause the
cyclone to quickly weaken. The NHC intensity forecast is similar to
the previous one, and not too different than the intensity model
consensus, IVCN.

Users are reminded to not focus on the exact forecast track, as
strong winds and heavy rainfall extend well away from the center of
Odile.  In addition, moisture from a disturbance over northeastern
Mexico and the Pacific ITCZ is forecast to be advected by Odile's
circulation northwestward across Mexico into the southwestern United
States by early next week.   This could result in heavy rains and
life-threatening flash flooding in those areas.  Please see
information from your local weather office for more details.

FORECAST POSITIONS AND MAX WINDS

INIT  14/1500Z 20.0N 108.2W  115 KT 135 MPH
 12H  15/0000Z 21.7N 109.6W  120 KT 140 MPH
 24H  15/1200Z 23.5N 111.4W  120 KT 140 MPH
 36H  16/0000Z 24.9N 112.8W  100 KT 115 MPH
 48H  16/1200Z 25.9N 113.8W   85 KT 100 MPH
 72H  17/1200Z 27.5N 115.5W   55 KT  65 MPH
 96H  18/1200Z 28.1N 116.2W   40 KT  45 MPH
120H  19/1200Z 28.3N 116.0W   30 KT  35 MPH

$$
Forecaster Cangialosi

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