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Hurricane Willa Intermediate Advisory Number 12A
NWS National Hurricane Center Miami FL       EP242018
1200 AM MDT Tue Oct 23 2018

...DANGEROUS WILLA EXPECTED TO BRING LIFE-THREATENING STORM SURGE,
WIND, AND RAINFALL TO PORTIONS OF WEST-CENTRAL AND SOUTHWESTERN
MEXICO...


SUMMARY OF 1200 AM MDT...0600 UTC...INFORMATION
-----------------------------------------------
LOCATION...20.6N 107.3W
ABOUT 80 MI...130 KM SW OF LAS ISLAS MARIAS MEXICO
ABOUT 190 MI...305 KM SSW OF MAZATLAN MEXICO
MAXIMUM SUSTAINED WINDS...140 MPH...225 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...942 MB...27.82 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 1200 AM MDT (0600 UTC), the center of Hurricane Willa was located
near latitude 20.6 North, longitude 107.3 West. Willa is moving
toward the north near 9 mph (15 km/h). A turn toward the north-
northeast is expected later this morning, followed by a faster
motion toward the northeast by this evening. On the forecast track,
the center of Willa will move near or over Las Islas Marias later
this morning and afternoon and make landfall within the hurricane
warning area along the west-central coast of mainland Mexico later
afternoon or this evening.

Maximum sustained winds have decreased to near 140 mph (225 km/h)
with higher gusts. Willa is an extremely dangerous category 4
hurricane on the Saffir-Simpson Hurricane Wind Scale. While gradual
weakening is forecast today, Willa is expected to be a dangerous
major hurricane when it reaches the coast of Mexico. Rapid weakening
is expected after landfall tonight and Wednesday.

Hurricane-force winds extend outward up to 35 miles (55 km) from
the center and tropical-storm-force winds extend outward up to 125
miles (205 km).

The estimated minimum central pressure is 942 mb (27.82 inches).


HAZARDS AFFECTING LAND
----------------------
STORM SURGE:  An extremely dangerous storm surge is likely along
portions of the coast of southwestern Mexico in southern Sinaloa
and Nayarit, 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, southern
Sinaloa, and far southern Durango 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 the rest of Durango and portions of Zacateca,
southeast Chihuahua, and Coahuila, 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 this afternoon, with tropical storm
conditions expected later this morning. Tropical storm conditions
are expected within the tropical storm warning areas this morning
and continuing into this afternoon.

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.  Swells should begin to affect portions
of the coast of the southern Baja California peninsula later today.
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 300 AM MDT.

$$
Forecaster Stewart

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