Official Discussion issued by the National Hurricane Center

Katia (AL132017) DATA RELEASED: 9/7/2017 4:00:00 PM UTC

Copy of official data

Hurricane Katia Discussion Number   9
NWS National Hurricane Center Miami FL       AL132017
400 PM CDT Thu Sep 07 2017

Katia has changed little in organization since this morning, with
limited convective banding features.  An eye has not yet become
apparent in satellite imagery.  The current intensity is held at 70
kt which is roughly the mean of Dvorak estimates from TAFB and SAB.
An Air Force Reserve Unit Hurricane Hunter aircraft is scheduled to
investigate Katia this evening to check its intensity.  Global
models continue to show a well-developed upper-level outflow
structure tonight and Friday, and strengthening is likely prior to
landfall.  The official intensity forecast is above the model
consensus, and it is possible that Katia will approach major
hurricane status prior to crossing the coast of Mexico early
Saturday.

Comparing afternoon satellite position estimates to reconnaissance
center fixes from this morning, there does not appear to have been
much motion today.  A mid-level ridge is forecast to build to the
north of Katia during the next day or so.  This should cause Katia
to move generally southwestward, and make landfall in Mexico in 36
hours or so.  The official track forecast has been shifted just
slightly southward and is mainly a blend of the latest simple and
corrected consensus guidance tracks.

FORECAST POSITIONS AND MAX WINDS

INIT  07/2100Z 21.6N  94.6W   70 KT  80 MPH
12H  08/0600Z 21.3N  95.0W   80 KT  90 MPH
24H  08/1800Z 20.9N  95.6W   90 KT 105 MPH
36H  09/0600Z 20.3N  96.7W   90 KT 105 MPH
48H  09/1800Z 19.5N  97.6W   40 KT  45 MPH...INLAND
72H  10/1800Z...DISSIPATED

$$
Forecaster Pasch