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Tropical Storm Lidia Discussion Number   6
NWS National Hurricane Center Miami FL       EP142017
900 PM MDT Wed Aug 30 2017

Satellite images indicate that the circulation, although broad, is
more consolidated, and convection has become more concentrated near
the center. However, there is no evidence of an inner core at this
time. Data from a unmanned NASA Global Hawk aircraft currently in
the area of Lidia, and observations from the Mexican Navy automatic
weather stations, were very helpful in determining the structure of
the cyclone. The best estimate of the initial intensity is 35 kt.

Lidia is within a very favorable environment of low shear, and the
ocean is warm.  The only factor against a higher intensification
rate appears to be the large size of the cyclone. The NHC forecast
calls for gradual strengthening during the next 12 to 24 hours, and
Lidia has a chance to be near hurricane strength before the cyclone
begins to interact with the high terrain of the Baja California
peninsula. After that time, gradual weakening should then begin.

The overall circulation is still moving toward the north-northwest
or 345 degrees at 6 kt. Lidia is being steered by the flow between
a weak ridge over Mexico and a weak cyclonic gyre to the west. This
pattern will persist, and the cyclone should continue on the same
general track for the next 2 days. Once the cyclone reaches the
central portion of Baja California peninsula, a ridge to the north
is forecast to amplify, and this flow pattern will force a weaker
Lidia on a more west-northwest track toward cold waters.

It is important to emphasize that Lidia is a large system
accompanied by very heavy rains which are already occuring over
portions of western Mexico and Baja California Sur. These rains are
already causing threatening flash floods and mudslides and
regardless of exactly how strong Lidia becomes, this should be a
significant hazard.

FORECAST POSITIONS AND MAX WINDS

INIT  31/0300Z 20.7N 109.2W   35 KT  40 MPH
 12H  31/1200Z 21.6N 109.5W   45 KT  50 MPH
 24H  01/0000Z 22.8N 110.0W   55 KT  65 MPH
 36H  01/1200Z 23.8N 110.6W   45 KT  50 MPH...INLAND
 48H  02/0000Z 25.5N 111.7W   40 KT  45 MPH...INLAND
 72H  03/0000Z 28.0N 114.3W   25 KT  30 MPH...INLAND
 96H  04/0000Z 29.0N 117.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  05/0000Z 29.5N 119.5W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Avila

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