ZCZC MIATCPAT1 ALL TTAA00 KNHC DDHHMM BULLETIN Tropical Storm Irma Intermediate Advisory Number 51A NWS National Hurricane Center Miami FL AL112017 800 PM EDT Mon Sep 11 2017 ...IRMA WEAKENING BUT HEAVY RAINS CONTINUE ACROSS THE SOUTHEASTERN UNITED STATES... SUMMARY OF 800 PM EDT...0000 UTC...INFORMATION ---------------------------------------------- LOCATION...31.9N 84.4W ABOUT 55 MI...85 KM SE OF COLUMBUS GEORGIA ABOUT 120 MI...195 KM S OF ATLANTA GEORGIA MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...NNW OR 330 DEGREES AT 16 MPH...26 KM/H MINIMUM CENTRAL PRESSURE...986 MB...29.12 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Storm Surge Warning has been discontinued from north of Clearwater Beach to the Aucilla River. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * North of Fernandina Beach to the South Santee River A Tropical Storm Warning is in effect for... * North of Altamaha Sound to the South Santee River A Storm Surge Warning means there is a danger of life-threatening inundation from rising water moving inland from the coastline, in this case during the next 12 hours, in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. Interests elsewhere in the southeastern United States should monitor the progress of Irma. For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ At 800 PM EDT (0000 UTC), the center of Tropical Storm Irma was located near latitude 31.9 North, longitude 84.4 West. Irma is moving toward the north-northwest near 16 mph (26 km/h), and a turn toward the northwest is expected by Tuesday morning. On the forecast track, the center of Irma will continue to move over southwestern Georgia tonight and move into Alabama on Tuesday. Maximum sustained winds have decreased to near 45 mph (75 km/h) with higher gusts. Continued weakening is forecast, and Irma is likely to become a tropical depression on Tuesday. Tropical-storm-force winds extend outward up to 415 miles (665 km) from the center. The estimated minimum central pressure based on surface observations is 986 mb (29.12 inches). HAZARDS AFFECTING LAND ---------------------- 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... Bonita Beach to Ochlockonee River, including Tampa Bay...1 to 3 ft South Santee River to North of Fernandina Beach...2 to 4 ft Fernandina Beach to Flagler/Volusia County line, including the St. Johns River...1 to 3 ft The deepest water will occur along the immediate coast in areas of onshore winds, 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. WIND: Tropical storm conditions are expected in portions of the warning area into tonight. Rainfall: Irma is expected to produce the following rain accumulations through Wednesday: South Carolina and north-central Georgia and Alabama into the southern Appalachians...3 to 6 inches with isolated 10 inches. Northern Mississippi and southern portions of Tennessee and North Carolina...2 to 4 inches. TORNADOES: Isolated tornadoes are possible tonight along the South Carolina coast. SURF: Swells generated by Irma are affecting the southeast coast of the United States. 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 1100 PM EDT. $$ Forecaster Berg NNNN