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Hurricane Katia Discussion Number  11
NWS National Hurricane Center Miami FL       AL132017
400 AM CDT Fri Sep 08 2017

Enhanced BD-curve infrared imagery and a GPM microwave composite
image indicate improved banding over the western portion of the
circulation and the earlier ragged eye presentation has become much
more distinct.  Subsequently, Dvorak satellite intensity estimates
have increased along with the Objective ADT T-number, and the
initial intensity is bumped up to 80 kt.  Further strengthening is
possible, and Katia could be near major hurricane intensity prior to
landfall Saturday morning.  After landfall, rapid weakening is
expected, and Katia is forecast to dissipate over the rugged terrain
of the Sierra Madre mountains after the 48 hour period.

The initial motion estimate is west-southwestward, or 250/3 kt.  A
continued slow west-southwestward motion under the influence of a
mid-latitude high extending east from Texas is forecast until the
cyclone makes landfall and quickly dissipates. The official forecast
has changed little from the previous one, and is based primarily on
the HFIP Corrected Consensus multi-model.

In addition to the hurricane-force winds, very heavy rains
associated with Katia are expected to affect eastern Mexico. These
rains could cause life-threatening flash floods and mudslides.


FORECAST POSITIONS AND MAX WINDS

INIT  08/0900Z 21.3N  95.4W   80 KT  90 MPH
 12H  08/1800Z 21.0N  96.0W   85 KT 100 MPH
 24H  09/0600Z 20.3N  97.0W   90 KT 105 MPH...INLAND
 36H  09/1800Z 19.3N  98.2W   40 KT  45 MPH...INLAND
 48H  10/0600Z...DISSIPATED

$$
Forecaster Roberts

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