| They forecast some weakening before landfall, but "Willa is still expected to be near major hurricane strength when it makes landfall along the west-central coast of Mexico." Track: https://www.nhc.noaa.gov/refresh/graphics_ep4+shtml/?cone#contents Floater: https://www.ssd.noaa.gov/PS/TROP/floaters/24E/24E_floater.html Wider East Pacific views: https://www.ssd.noaa.gov/PS/TROP/trop-epac.html NHC: https://www.nhc.noaa.gov/#Willa Hurricane Willa Discussion Number 9 NWS National Hurricane Center Miami FL EP242018 300 AM MDT Mon Oct 22 2018 Willa is an impressive hurricane with rapid to explosive deepening having occurred over the past 48 hours, and yielding a 105-kt intensity increase during that time. Satellite intensity estimates range from subjective Dvorak T-numbers of T6.5/127 kt from TAFB and SAB to objective T-numbers of T7.0/140 kt from UW-CIMSS ADT and NHC. The most recent UW-CIMSS SATCON value around 0437Z was 127 kt. Based on these data and the slightly more ragged appearance of the CDO over the past couple of hours, the intensity is raised to 135 kt, which is just below category 5 strength. Willa is now moving northward and the initial motion estimate is 360/06 kt. Willa is forecast to continue moving northward today as the hurricane rounds the western portion of a deep-layer ridge located over central Mexico and which extends westward along 20N latitude to near the Pacific coast of Mexico. On Tuesday, a turn toward the north-northeast and northeast at a slightly faster forward speed is expected as the hurricane gets caught up in southwesterly flow ahead of an approaching mid-/upper-level trough. The latest 00Z NHC model guidance is in decent agreement on this general track scenario, but with noticeable differences in the forward speed. Internal statistical analyses show that the ECMWF and UKMET models have had a slow westward bias over the past 48 hours, which has significantly affected the consensus models. As a result, the new NHC forecast is a little to the right of and slightly faster the previous advisory track and the consensus models, and lies close to GFS model which has verified the best thus far. On the forecast track, Willa is expected to move over Las Islas Marias on Tuesday and then move inland over southwestern and west-central Mexico Tuesday night or early Wednesday. A 72-hour position has been provided only for continuity purposes beyond the 48-hour period, and Willa will likely have dissipated by then. Water temperatures ahead of the powerful hurricane are forecast to increase from 28 deg C to near 29.5 deg C, and the depth of the warm water is also expected to increase, which would tend to offset any cold upwelling beneath Willa. The deep-layer shear is forecast to increase to a little more than 10 kt during the next 36 hours, and remain at that level during the duration of that time period. These conditions would favor at least slight strengthening before the internal dynamics of the hurricane in the form of an eyewall replacement cycle (ERC) induces some weakening. With the eye diameter already at 10-15 nmi, an ERC could begin at any time during the next 12 hours. Shortly after 36 hours, the shear is expected to increase sharply to more than 20 kt, which will cause more significant weakening. However, Willa is still expected to be near major hurricane strength when it makes landfall along the west-central coast of Mexico. After landfall, the mountainous terrain along with strong southwesterly wind shear of more than 30 kt will cause rapid weakening and dissipation of the cyclone inland over north-central Mexico. Key Messages: 1. Willa is forecast to be a dangerous hurricane when it reaches the Islas Marias and the coast of southwestern Mexico by late Tuesday or Wednesday morning, bringing a life-threatening storm surge and flash flooding along with damaging hurricane-force winds. A Hurricane Warning is in effect for these areas, and residents should rush preparations to completion to protect life and property and follow any advice given by local officials. FORECAST POSITIONS AND MAX WINDS INIT 22/0900Z 18.2N 107.1W 135 KT 155 MPH 12H 22/1800Z 19.2N 107.2W 135 KT 155 MPH 24H 23/0600Z 20.4N 107.2W 125 KT 145 MPH 36H 23/1800Z 21.8N 106.5W 115 KT 130 MPH 48H 24/0600Z 23.8N 104.6W 50 KT 60 MPH...INLAND WNCTRL MEXICO 72H 25/0600Z 27.0N 99.5W 20 KT 25 MPH...POST-TROP/INLAND 96H 26/0600Z...DISSIPATED INLAND $$ Forecaster Stewart 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 Recon is scheduled for later today: NOUS42 KNHC 211718 REPRPD WEATHER RECONNAISSANCE FLIGHTS CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL. 0115 PM EDT SUN 21 OCTOBER 2018 SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD) VALID 22/1100Z TO 23/1100Z OCTOBER 2018 TCPOD NUMBER.....18-150 I. ATLANTIC REQUIREMENTS 1. NEGATIVE RECONNAISSANCE REQUIREMENTS. 2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE. II. PACIFIC REQUIREMENTS 1. HURRICANE WILLA FLIGHT ONE -- TEAL 71 A. 22/1730Z B. AFXXX 0124E WILLA C. 22/1300Z D. 19.7N 107.6W E. 22/1700Z TO 22/2030Z F. SFC TO 10,000 FT 2. OUTLOOK FOR SUCCEEDING DAY: FIX WILLA AT 23/1730Z NEAR 21.2N 107.0W. $$ SEF From: https://www.nhc.noaa.gov/recon.php |