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Tropical Storm Lorena Discussion Number   3
NWS National Hurricane Center Miami FL       EP152019
1000 PM CDT Tue Sep 17 2019

There has been little change in the cloud structure of Lorena since
the last advisory, with the storm having a central convective
feature and a ragged band in the western semicircle.  A recently-
received WindSat overpass indicates the low-level center is located
near the northwestern edge of the central convection.  The initial
intensity remains 45 kt in good agreement with a subjective
satellite estimate from TAFB.

The initial motion is 305/13.  A mid- to upper-level ridge over
Mexico should steer Lorena generally northwestward with some
decrease in forward speed during the forecast period, with the
center likely to pass near the southwestern coast of Mexico late
Wednesday through Thursday.  The guidance has shifted a little to
the left since the last advisory, and the new forecast track keeps
the center of Lorena a little farther offshore than than the
previous forecast.  However, any motion to the right of the track
would bring the center onshore in southwestern Mexico and cause
rapid dissipation.  If the center stays offshore, Lorena is forecast
to be near the southern portion of the Baja California peninsula by
the end of the forecast period.

Conditions appear favorable for slow strengthening as Lorena
approaches the southwestern coast of Mexico.  Based on the forecast
track now staying offshore, the new intensity forecast calls for a
stronger storm by 48-72 h, with Lorena now forecast to be just under
hurricane strength.  This peak would be followed by a weakening
trend as Lorena gradually moves over cooler water.  An alternative
intensity forecast is for Lorena to dissipate if the center moves
onshore in southwestern Mexico.


Key Messages:

1. Lorena is forecast to cause heavy rain over portions of the
Mexican states of Guerrero, Michoacan, Colima, and Jalisco during
the next few days.  This rainfall may produce life-threatening flash
flooding and mudslides.

2. Tropical storm conditions are expected along a portion of the
southwestern coast of Mexico by late Wednesday.


FORECAST POSITIONS AND MAX WINDS

INIT  18/0300Z 15.1N 102.1W   45 KT  50 MPH
 12H  18/1200Z 16.3N 103.0W   50 KT  60 MPH
 24H  19/0000Z 17.7N 104.0W   50 KT  60 MPH
 36H  19/1200Z 18.6N 104.7W   55 KT  65 MPH
 48H  20/0000Z 19.3N 105.4W   60 KT  70 MPH
 72H  21/0000Z 20.6N 107.3W   60 KT  70 MPH
 96H  22/0000Z 22.0N 110.0W   55 KT  65 MPH
120H  23/0000Z 24.5N 112.5W   45 KT  50 MPH

$$
Forecaster Beven

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