ZCZC MIATCPAT5 ALL TTAA00 KNHC DDHHMM BULLETIN Hurricane Maria Intermediate Advisory Number 18A NWS National Hurricane Center Miami FL AL152017 200 PM AST Wed Sep 20 2017 ...AIR FORCE HURRICANE HUNTER PLANE FINDS MARIA'S CENTER JUST OFFSHORE OF THE NORTHWESTERN COAST OF PUERTO RICO... SUMMARY OF 200 PM AST...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...18.5N 66.9W ABOUT 15 MI...20 KM W OF ARECIBO PUERTO RICO ABOUT 95 MI...155 KM E OF PUNTA CANA DOMINICAN REPUBLIC MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H PRESENT MOVEMENT...NW OR 305 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...961 MB...28.38 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * U.S. Virgin Islands * British Virgin Islands * Puerto Rico, Culebra, and Vieques * Dominican Republic from Cabo Engano to Puerto Plata * Turks and Caicos Islands and the Southeastern Bahamas A Tropical Storm Warning is in effect for... * Dominican Republic west of Puerto Plata to the northern border of the Dominican Republic and Haiti * Dominican Republic west of Cabo Engano to Punta Palenque A Hurricane Watch is in effect for... * Dominican Republic from Isla Saona to Cabo Engano A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. 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. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Interests elsewhere in Hispaniola and the Bahamas should monitor the progress of Maria. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside the United States, please monitor products issued by your national meteorological service. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ At 200 PM AST (1800 UTC), the center of Hurricane Maria was located by an Air Force Reserve Hurricane Hunter aircraft just offshore of the northwestern coast of Puerto Rico near latitude 18.5 North, longitude 66.9 West. Maria is moving toward the northwest near 12 mph (19 km/h), and this general motion with a gradual decrease in forward speed is expected through early Friday. On the forecast track, the center of Maria will move away from the northwestern coast of Puerto Rico this afternoon. The center will then pass offshore of the northeastern coast of the Dominican Republic tonight and Thursday and then move near the Turks and Caicos Islands and southeastern Bahamas Thursday night and Friday. Maximum sustained winds are near 115 mph (185 km/h) with higher gusts. Maria is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Little change in strength is forecast during the next 48 hours, and Maria is expected to remain a dangerous major hurricane through Friday. Hurricane-force winds extend outward up to 60 miles (95 km) from the center, and tropical-storm-force winds extend outward up to 150 miles (240 km). A sustained wind of 45 mph (72 km/h) with a gust to 77 mph (124 km/h) was recently reported at Mayaguez, Puerto Rico. A sustained wind of 46 mph (74 km/h) with a gust to 76 mph (122 km/h) was recently reported at Cabo Rojo, Puerto Rico. The minimum central pressure based on the aircraft data is 961 mb (28.38 inches). HAZARDS AFFECTING LAND ---------------------- WIND: Hurricane conditions are occurring over portions of Puerto Rico, and tropical storm conditions are continuing over the remainder of Puerto Rico and the Virgin Islands. Tropical storm conditions are likely beginning in the warning areas in the Dominican Republic, and hurricane conditions should start in the hurricane warning area tonight. Tropical storm conditions are expected to begin in the Turks and Caicos Islands and the southeastern Bahamas Thursday morning, with hurricane conditions starting Thursday evening. Wind speeds atop and on the windward sides of hills and mountains and on high-rise buildings could be much stronger than the near- surface winds indicated in this advisory. STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water is expected to reach the following heights above ground if the peak surge occurs at the time of high tide... Puerto Rico...6 to 9 ft The deepest water will occur along the immediate coast near and to the north and east of the landfall location, where the surge will be accompanied by large and destructive waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office. A dangerous storm surge accompanied by large and destructive waves will raise water levels by as much as 4 to 6 feet above normal tide levels in the hurricane warning area in the Dominican Republic, and 1 to 3 ft elsewhere along the northern coasts of the Dominican Republic and Haiti. A dangerous storm surge accompanied by large and destructive waves will raise water levels by as much as 10 to 15 feet above normal tide levels in the hurricane warning area near and to the north of the center of Maria for both the Southeastern Bahamas and the Turks and Caicos Islands. RAINFALL: Maria is expected to produce the following rainfall totals through Friday: Puerto Rico...20 to 25 inches, isolated 35 inches U.S. and British Virgin Islands...additional 5 to 10 inches, isolated 15 inches Northern and eastern Dominican Republic, Turks and Caicos and southeast Bahamas...8 to 16 inches, isolated 20 inches Northern Haiti...2 to 4 inches Rainfall on these islands will cause life-threatening flash floods and mudslides TORNADOES: Several tornadoes are possible over Puerto Rico and the U.S. Virgin Islands today. SURF: Swells generated by Maria are affecting the Leeward Islands, Puerto Rico, and the Virgin Islands. These swells will begin affecting the northern coast of Hispaniola, the Turks and Caicos Islands, and the Southeastern Bahamas during the next day or two. 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 500 PM AST. $$ Forecaster Berg NNNN