ZCZC MIATCPAT5 ALL TTAA00 KNHC DDHHMM BULLETIN Hurricane Tammy Intermediate Advisory Number 9A NWS National Hurricane Center Miami FL AL202023 200 PM AST Fri Oct 20 2023 ...CENTER OF TAMMY EXPECTED TO APPROACH THE LEEWARD ISLANDS TONIGHT... ...HEAVY RAINFALL AND FLOODING LIKELY OVER MUCH OF THE LESSER ANTILLES... SUMMARY OF 200 PM AST...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...14.1N 58.9W ABOUT 145 MI...235 KM ESE OF MARTINIQUE ABOUT 225 MI...365 KM SE OF GUADELOUPE MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H PRESENT MOVEMENT...WNW OR 285 DEGREES AT 7 MPH...11 KM/H MINIMUM CENTRAL PRESSURE...991 MB...29.26 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Dominica has issued a Hurricane Watch for Dominica. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * Guadeloupe * Antigua, Barbuda, Montserrat, St. Kitts and Nevis A Hurricane Watch is in effect for... * Dominica * Anguilla * St. Maarten * St. Martin and St. Barthelemy A Tropical Storm Warning is in effect for... * Dominica * Anguilla * St. Maarten * St. Martin and St. Barthelemy * Saba and St. Eustatius A Tropical Storm Watch is in effect for... * Barbados * Martinique A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area, in this case within the next 24 hours. Preparations to protect life and property should be rushed to completion. A Hurricane Watch means that hurricane conditions are possible within the watch area, in this case within the next 24 hours. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Additional watches and warnings could be required later today or tonight. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 200 PM AST (1800 UTC), the center of Hurricane Tammy was located near latitude 14.1 North, longitude 58.9 West. Tammy is moving toward the west-northwest near 7 mph (11 km/h), and this general motion is expected to continue through this afternoon. A turn toward the northwest is anticipated by this evening, followed by a north-northwestward and northward turn Saturday night through Sunday night. On the forecast track, the center of Tammy will move near or over portions of the Leeward Islands tonight and on Saturday, and then move north of the northern Leeward Islands on Sunday. Data from an Air Force Reserve reconnaissance aircraft indicate that the maximum sustained winds are near 75 mph (120 km/h) with higher gusts. Gradual strengthening is forecast during the next couple of days, and Tammy is expected to be a hurricane while it moves near or over portions of the Leeward Islands. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). The minimum central pressure estimated from reconnaissance aircraft data is 991 mb (29.26 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Tammy can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT5 and WMO header WTNT45 KNHC and on the web at hurricanes.gov/text/MIATCDAT5.shtml WIND: Tropical storm conditions are expected within the tropical storm warning area beginning later today or tonight. Hurricane conditions are expected in the hurricane warning area by late tonight or early Saturday. Hurricane conditions are possible in the hurricane watch area in the Leeward Islands on Saturday. Tropical storm conditions are possible within the tropical storm watch area beginning later today. RAINFALL: Tammy is expected to produce the following storm total rainfall: Leeward Islands: 4 to 8 inches with maximum amounts of 12 inches Northern Windward Islands: 2 to 4 inches with maximum amounts of 6 inches British and U.S. Virgin Islands into eastern Puerto Rico: 1 to 2 inches with maximum amounts of 4 inches These rains may produce isolated flash and urban flooding, along with isolated mudslides in areas of higher terrain. STORM SURGE: Storm surge could raise water levels by as much as 1 to 3 feet above normal tide levels near where the center of Tammy moves across the Leeward Islands. Near the coast, the surge will be accompanied by large and dangerous waves. SURF: Swells generated by Tammy will continue to affect portions of the Lesser Antilles 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 complete advisory at 500 PM AST. $$ Forecaster Brown NNNN