Tropical Storm ODILE

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TROPICAL STORM ODILE DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP152014
200 PM PDT WED SEP 10 2014

Odile is currently showing the effects of about 15 kt of
northeasterly vertical wind shear, with the low-level center partly
exposed on the northeastern edge of the main area of convection.
Satellite intensity estimates remain 45 kt from TAFB and 30 kt from
SAB.  Based on these data, the initial intensity remains a possibly
conservative 35 kt.

The initial motion is 320/5.  The various large-scale models
suggest that Odile will be caught in an area of weak steering
currents for the next 2-3 days, with a slow and erratic motion
expected during this time.  After that, a mid-level ridge north of
the cyclone should strengthen some and steer the cyclone toward the
northwest at a faster forward speed.  There are two notable changes
to the guidance since the last advisory.  First, most of the
guidance suggests a westward or southwestward motion during the
first 36 hours or so.  Second, the overall guidance envelope has
shifted to the left.  This includes the latest ECMWF model, which
forecasts a track farther from the coast of Mexico than its previous
run.  The new forecast track is shifted to the left in response to
these changes, although it lies to the right of the center of the
guidance envelope.  It should be noted that the GFDL and HWRF
models are still to the right of the new forecast, showing a track
close to mainland Mexico.

Odile is expected to remain in an area of moderate shear for the
next 24 hours or so, after which the large-scale models suggest the
shear should diminish.  This should allow at least steady
strengthening until the cyclone reaches colder water near the end of
the forecast period.  An alternative forecast scenario, supported by
the SHIPS and GFS models, is that Odile undergoes rapid
intensification after 24-36 hours when the shear diminishes.  The
new intensity forecast shows an increased intensity after 36 hours
in best general agreement with the intensity consensus.  However, it
is well below the SHIPS model, which forecasts Odile to be a major
hurricane by 72 hours.

A tropical storm watch could be needed for a portion of the coast of
southwestern Mexico tonight.  Regardless, locally heavy rains
are possible across that area later this week.


FORECAST POSITIONS AND MAX WINDS

INIT  10/2100Z 15.3N 103.2W   35 KT  40 MPH
 12H  11/0600Z 15.5N 103.4W   45 KT  50 MPH
 24H  11/1800Z 15.7N 103.7W   55 KT  65 MPH
 36H  12/0600Z 15.8N 103.9W   65 KT  75 MPH
 48H  12/1800Z 16.2N 104.3W   75 KT  85 MPH
 72H  13/1800Z 17.5N 105.5W   85 KT 100 MPH
 96H  14/1800Z 20.5N 108.5W   90 KT 105 MPH
120H  15/1800Z 24.0N 112.0W   90 KT 105 MPH

$$
Forecaster Beven

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