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BULLETIN
Hurricane Willa Intermediate Advisory Number 9A
NWS National Hurricane Center Miami FL       EP242018
600 AM MDT Mon Oct 22 2018

...EXTREMELY DANGEROUS HURRICANE WILLA MOVING NORTHWARD...
...EXPECTED TO PRODUCE LIFE-THREATENING STORM SURGE, WIND, AND
RAINFALL OVER PORTIONS OF WEST-CENTRAL AND SOUTHWESTERN MEXICO...


SUMMARY OF 600 AM MDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...18.7N 107.3W
ABOUT 200 MI...325 KM SSW OF LAS ISLAS MARIAS MEXICO
ABOUT 155 MI...255 KM SW OF CABO CORRIENTES MEXICO
MAXIMUM SUSTAINED WINDS...155 MPH...250 KM/H
PRESENT MOVEMENT...N OR 355 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...931 MB...27.49 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* San Blas to Mazatlan, including Las Islas Marias

A Tropical Storm Warning is in effect for...
* Playa Perula to San Blas
* North of Mazatlan to Bahia Tempehuaya

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area within the next 36 hours.
Preparations to protect life and property should be rushed to
completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.

Interests elsewhere along the coasts of west-central and
southwestern mainland Mexico should monitor the progress of Willa.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 600 AM MDT (1200 UTC), the eye of Hurricane Willa was located
near latitude 18.7 North, longitude 107.3 West.  Willa is moving
toward the north near 7 mph (11 km/h), and this general motion is
expected to continue today.  Willa is forecast to accelerate toward
the north-northeast and move over or very near the Islas Marias
early Tuesday and make landfall along the southwestern coast of
mainland Mexico in the hurricane warning area late Tuesday or
Tuesday night.

Maximum sustained winds are near 155 mph (250 km/h) with higher
gusts.  Willa is an extremely dangerous category 4 hurricane on the
Saffir-Simpson Hurricane Wind Scale.  Some slight strengthening is
possible today, and Willa could become a category 5 hurricane later
this morning.  While some weakening is forecast by tonight and
Tuesday, Willa is expected to be a dangerous hurricane when it
reaches the coast of Mexico.

Hurricane-force winds extend outward up to 30 miles (45 km) from
the center and tropical-storm-force winds extend outward up to 90
miles (150 km).

The estimated minimum central pressure is 931 mb (27.49 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE:  A dangerous storm surge is likely along portions of
the coast of southwestern Mexico by Tuesday or Tuesday night,
especially near and to the south of where the center of Willa makes
landfall.  Near the coast, the surge will be accompanied by large
and destructive waves.

RAINFALL:  Willa is expected to produce storm total rainfall
accumulations of 6 to 12 inches, with local amounts to 18 inches,
across portions of western Jalisco, western Nayarit, and southern
Sinaloa in Mexico.  This rainfall will cause life-threatening flash
flooding and landslides.

Farther inland, Willa is expected to produce rainfall amount of 2 to
4 inches across portions of Zacateca, Durango, southeast Chihuahua,
and Coahuila in Mexico, with local amounts to 6 inches possible.
This rainfall could cause life-threatening flash flooding.

WIND:  Hurricane conditions are expected within the hurricane
warning area beginning Tuesday afternoon, with tropical storm
conditions expected by Tuesday morning.  Tropical storm conditions
are expected within the tropical storm warning areas tonight and
Tuesday.

SURF:  Large swells generated by Willa will continue to affect
portions of the coast of southwestern and west-central Mexico
during the next few days. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 900 AM MDT.

$$
Forecaster Brown

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