000
WTNT43 KNHC 081440
TCDAT3

Hurricane Katia Discussion Number  12
NWS National Hurricane Center Miami FL       AL132017
Issued by the NWS Weather Prediction Center College Park MD
1000 AM CDT Fri Sep 08 2017

Infrared imagery and a GPM microwave composite data indicate
improved banding over the western portion of the circulation with
visible pictures showing the formation of a ragged eye. Subjective
Dvorak satellite intensity estimates from TAFB and SAB both
supported 80 kt winds earlier, and aircraft data suggested that
Katia has continued to intensify, so the initial intensity has been
increased to 85 knots.  Further strengthening is possible, and Katia
could be approaching 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 240/4 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 track forecast has
changed little from the previous one, and remains roughly in the
middle of the guidance.

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


FORECAST POSITIONS AND MAX WINDS

INIT  08/1500Z 21.0N  95.8W   85 KT 100 MPH
 12H  09/0000Z 20.6N  96.4W   90 KT 105 MPH
 24H  09/1200Z 19.7N  97.4W   45 KT  50 MPH...INLAND
 36H  10/0000Z 19.1N  98.4W   25 KT  30 MPH...POST-TROP/INLAND
 48H  10/1200Z...DISSIPATED

$$
Forecaster Bann/Carbin