Hurricane Willa remains a dangerous Category 4 in the Eastern Pacific Ocean and will threaten Mexico with destructive winds, life-threatening storm surge and flooding rainfall as it makes landfall Tuesday.
Willa achieved Category 5 intensity at 11 a.m. EDT Monday before weakening slightly back to a Category 4 by 5 p.m. EDT Monday, but the difference in impacts between a Category 4 and 5 hurricane is negligible.
A hurricane warning is in effect from San Blas to Mazatlán, including Las Islas Marias. A tropical storm warning is in effect from Playa Perula to San Blas and from north of Mazatlán to Bahia Tempehuaya.
Willa is tracking northward and will turn to the north-northeast by Tuesday. It should approach landfall along the southwestern coast of mainland Mexico Tuesday afternoon or evening, which is expected to occur anywhere from near Mazatlán to the north of Puerto Vallarta.
Tropical storm conditions (39- to 73-mph winds) could arrive as early as Tuesday morning in the hurricane warning area. By Tuesday afternoon, hurricane conditions (74-plus-mph winds) will develop along that same stretch of the coastline.
Tropical storm conditions are expected to develop within the tropical storm warning areas by early Tuesday.
Increasing wind shear will lead to some slight weakening as Willa approaches landfall, but it will still be a strong and dangerous hurricane as it moves inland Tuesday.
Where the core of Willa's most intense winds roars ashore, there will likely be widespread tree damage, power outages and structural damage.
Rough surf will continue to affect parts of the southwestern and west-central Mexico coastline, contributing to a high risk of rip currents during the next few days, the National Hurricane Center (NHC) said.
Those in low-lying areas near the coast where Willa is forecast to push inland should seek higher ground due to the threat of life-threatening storm surge flooding. Follow the advice of local officials for any evacuations. The worst storm surge inundation will occur near and just south of where Willa's center crosses the coast.
Locally, up to 18 inches of rain is possible in western Jalisco, western Nayarit and southern Sinaloa in Mexico, according to the NHC. Up to 6 inches of rain is possible farther inland across Zacateca, Durango, southeastern Chihuahua and Coahuila.
Dangerous flash flooding and landslides will occur because of the heavy rain in those areas.
After dissipating over Mexico's mountainous terrain, the remnant upper-level energy and moisture from Willa could eventually enhance rainfall in Texas and perhaps the northern Gulf Coast Wednesday into Thursday.
Willa's Rapid Intensification
Hurricane Willa's maximum sustained winds increased by 55 mph in the 24 hours ending 5 p.m. EDT Sunday, easily meeting the criteria for rapid intensification. Willa's winds increased by an additional 25 mph during the following three hours from 5 p.m. to 8 p.m. EDT Sunday.
At 11 a.m. EDT Monday, Willa became a Category 5 hurricane with maximum sustained winds of 160 mph. That means Willa's winds increased from 40 mph when it was first named Saturday at 11 a.m. EDT to 160 mph just 48 hours later.
Willa is just the fourth Eastern Pacific hurricane to reach Category 5 strength in the month of October dating to 1971. The others were Patricia (2015), Rick (2009) and Kenna (2002).
Tropical Storm Vicente
Tropical Storm Vicente is a very small tropical cyclone but will continue to pose a threat of heavy rain to southern Mexico early this week.
Vicente is forecast to weaken as it remains just offshore or near the southern coast of Mexico through Tuesday. It could make landfall as a tropical depression or dissipate before reaching Mexico's southwestern coast later Tuesday.
Regardless, the main threat from Vicente is heavy rainfall. Vicente or its remnant is expected to produce 3 to 6 inches of rain in parts of southern Mexico, with locally up to 10 inches over portions of Guerrero, Michoaca, Colima and Jalisco.
Flash flooding and landslides could threaten southern Mexico, particularly in the mountainous terrain.