000
WTPZ44 KNHC 311439
TCDEP4

Tropical Storm Lidia Discussion Number   8
NWS National Hurricane Center Miami FL       EP142017
900 AM MDT Thu Aug 31 2017

Conventional and microwave satellite data indicate that Lidia has
become better organized this morning, with interlocking convective
bands forming around a much better defined center.  Satellite
intensity estimates from TAFB and SAB have increased to 45 kt, and
the latest CIMSS ADT estimate is close to 55 kt.  The initial
intensity is increased to 45 kt, and this could be conservative.

The initial motion is north-northwestward or 340/8 kt between a
mid-level anticyclone centered over central Mexico and a mid- to
upper-level low located to the west over the Pacific.  This motion
should continue for the next 24-36 hours.  After that time, a
mid-level anticyclone over the southwestern United States should
become the main steering influence and force Lidia to turn
northwestward and west-northwestward on days 2 through 5.  While
there remains some spread in the speed, the guidance is tightly
clustered on the track, and the new forecast is similar to both the
previous forecast and the various consensus models.

Additional strengthening is likely today before the center moves
close to the Baja California peninusla, and while the chance of
Lidia becoming a hurricane is low it is non-zero.  Weakening is
expected after 12 hours due to the center moving up the spine of the
Baja California peninsula, but tropical-storm-force winds are likely
to spread up the Gulf of California well east of the center.  Lidia
is forecast to become a remnant low by day 3 due to its interaction
with land, and further weakening is anticipated over the cold waters
of the California Current on days 4 and 5.

Lidia is a large system accompanied by very heavy rains which are
already occurring over portions of western Mexico and Baja
California Sur.  Regardless of how strong Lidia becomes,
life-threatening flash floods and mudslides will be a significant
hazard over these areas.  In addition, the mountainous terrain of
the Baja California peninsula could enhance the winds at higher
elevations.


FORECAST POSITIONS AND MAX WINDS

INIT  31/1500Z 22.3N 109.7W   45 KT  50 MPH
 12H  01/0000Z 23.3N 110.2W   55 KT  65 MPH
 24H  01/1200Z 24.6N 111.1W   50 KT  60 MPH...INLAND
 36H  02/0000Z 26.1N 112.2W   45 KT  50 MPH...INLAND
 48H  02/1200Z 27.6N 113.5W   40 KT  45 MPH...INLAND
 72H  03/1200Z 30.0N 117.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  04/1200Z 30.5N 119.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  05/1200Z 30.5N 122.0W   15 KT  15 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven