000 WTPZ34 KNHC 220838 TCPEP4 BULLETIN Hurricane Willa Advisory Number 9 NWS National Hurricane Center Miami FL EP242018 300 AM MDT Mon Oct 22 2018 ...EXTREMELY DANGEROUS HURRICANE WILLA MOVING SLOWLY NORTHWARD... ...EXPECTED TO PRODUCE LIFE-THREATENING STORM SURGE, WIND, AND RAINFALL OVER PORTIONS OF WEST-CENTRAL AND SOUTHWESTERN MEXICO... SUMMARY OF 300 AM MDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...18.2N 107.1W ABOUT 230 MI...375 KM S OF LAS ISLAS MARIAS MEXICO ABOUT 175 MI...285 KM SSW OF CABO CORRIENTES MEXICO MAXIMUM SUSTAINED WINDS...155 MPH...250 KM/H PRESENT MOVEMENT...N OR 360 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. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. 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 within 36 hours. 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 300 AM MDT (0900 UTC), the center of the eye of Hurricane Willa was located near latitude 18.2 North, longitude 107.1 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 on Tuesday and make landfall along the southwestern coast of mainland Mexico in the hurricane warning area Tuesday night or Wednesday morning. 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 late Tuesday or early Wednesday. 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 by late Tuesday, 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 intermediate advisory at 600 AM MDT. Next complete advisory at 900 AM MDT. $$ Forecaster Stewart