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Hurricane Lorena Discussion Number  15
NWS National Hurricane Center Miami FL       EP152019
900 PM MDT Fri Sep 20 2019

The eye of Lorena passed near or over the Cabo Pulmo area of the
Baja California peninsula a few hours ago and is currently located
just off of the east coast of the peninsula east-southeast of La
Paz.  Satellite imagery indicates that the hurricane remains well
organized, with cold eyewall cloud tops surrounding a cloud-filled
eye.  Based on the land interaction that has occurred since the last
advisory, the initial intensity is lowered to a possibly
conservative 70 kt.

Lorena has continued to move to the right of the previous forecast
track, and the initial motion is now 330/7.  The hurricane is
mostly being steered by a mid- to upper-level ridge over northern
Mexico, and it is moving toward a break in the ridge caused by a
large mid- to upper-level trough over the western United States.
This combination should steer Lorena generally north-northwestward
for the next 2-3 days.  The track guidance has continued to shift
to the right since the last advisory.  As a result, the new forecast
track has also shifted and now calls for the center of Lorena to
move up the length of the Gulf of California.  However, the GFS,
the old version of the GFS, and the ECMWF are all to the right of
the current track, with these models forecasting a more northward
motion into mainland Mexico. Thus, additional adjustments to the
forecast track may be required on subsequent advisories.  The new
forecast track requires significant changes to the watches and
warnings for the Baja California peninsula and northwestern mainland
Mexico.

Lorena should spend another 24-36 h over the warm waters of the
Gulf of California in light to moderate shear conditions.  The
intensity guidance does not show much strengthening during this
time, and the official forecast follows the guidance.  However, it
would not be a surprise if Lorena strengthened a little given the
current structure.  After that, the cyclone should encounter
strong shear which would likely cause steady to even rapid
weakening, and the intensity forecast has the system weakening to a
remnant low as it reaches the northern end of the Gulf of
California. If the cyclone makes an earlier landfall in mainland
Mexico, it will likely dissipate faster than currently forecast.

Key Messages:

1. Regardless of any changes in track, Lorena will produce heavy
rain, with life-threatening flash floods possible this weekend in
parts of Baja California and northwest Mexico.  Moisture associated
with Lorena is forecast to bring a chance for heavy rain to the
southwest United States from late this weekend into early next week.

2. Lorena is forecast to bring hurricane-force winds to a portion of
the southern Baja California peninsula through tonight, where a
Hurricane Warning is in effect.  It could also bring hurricane
conditions to portions of mainland Mexico where a Hurricane Watch
has been issued.

FORECAST POSITIONS AND MAX WINDS

INIT  21/0300Z 24.0N 109.7W   70 KT  80 MPH
 12H  21/1200Z 25.0N 110.5W   70 KT  80 MPH
 24H  22/0000Z 26.6N 111.3W   70 KT  80 MPH
 36H  22/1200Z 28.1N 112.1W   65 KT  75 MPH
 48H  23/0000Z 29.4N 112.8W   50 KT  60 MPH
 72H  24/0000Z 31.5N 113.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  25/0000Z...DISSIPATED

$$
Forecaster Beven

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