000 WTNT31 KNHC 071737 TCPAT1 BULLETIN Hurricane Nate Intermediate Advisory Number 13A NWS National Hurricane Center Miami FL AL162017 100 PM CDT Sat Oct 07 2017 ...OUTER RAINBANDS OF NATE MOVING ONSHORE IN SOUTHEASTERN LOUISIANA... SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...27.6N 88.9W ABOUT 105 MI...170 KM S OF THE MOUTH OF THE MISSISSIPPI RIVER ABOUT 195 MI...315 KM S OF BILOXI MISSISSIPPI MAXIMUM SUSTAINED WINDS...90 MPH...150 KM/H PRESENT MOVEMENT...NNW OR 340 DEGREES AT 25 MPH...40 KM/H MINIMUM CENTRAL PRESSURE...982 MB...29.00 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * Grand Isle Louisiana to the Alabama/Florida border * Metropolitan New Orleans and Lake Pontchartrain A Storm Surge Warning is in effect for... * Morgan City Louisiana to the Okaloosa/Walton County Line Florida * Northern and western shores of Lake Pontchartrain A Tropical Storm Warning is in effect for... * Lake Maurepas * West of Grand Isle to Morgan City Louisiana * East of the Alabama/Florida border to Indian Pass Florida A Hurricane Watch is in effect for... * Lake Maurepas * East of the Alabama/Florida border to the Okaloosa/Walton County Line * West of Grand Isle to Morgan City Louisiana A Storm Surge Watch is in effect for... * East of the Okaloosa/Walton County Line to Indian Pass Florida A Tropical Storm Watch is in effect for... * West of Morgan City to Intracoastal City Louisiana 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 Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 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. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. A Hurricane Watch means that hurricane conditions are possible within the watch area. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. 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 100 PM CDT (1800 UTC), the center of Hurricane Nate was located near latitude 27.6 North, longitude 88.9 West. Nate is moving rapidly toward the north-northwest near 25 mph (40 km/h), and this general motion is expected to continue through this evening. A turn toward the north is forecast tonight, followed by a turn toward the northeast on Sunday. On the forecast track, the center of Nate will approach the mouth of the Mississippi during the next several hours and will make landfall along the central U.S. Gulf Coast tonight. Reports from an Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds are near 90 mph (150 km/h) with higher gusts. Strengthening is expected before landfall, and Nate is forecast to be a category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale when the center reaches the Gulf Coast. Hurricane-force winds extend outward up to 35 miles (55 km), primarily to the east of the center and tropical-storm-force winds extend outward up to 125 miles (205 km). The minimum central pressure estimated from the Hurricane Hunter aircraft data is 982 mb (29.00 inches). HAZARDS AFFECTING LAND ---------------------- WIND: Along the northern Gulf Coast, hurricane conditions are expected in the hurricane warning area beginning in the next several hours, with tropical storm conditions expected to begin during the next few hours. Tropical storm conditions are expected in the tropical storm warning area tonight and Sunday. Hurricane conditions are possible in the hurricane watch area tonight, and tropical storm conditions are possible in the tropical storm watch area tonight and Sunday. 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... Mouth of the Mississippi River to the Mississippi/Alabama border...7 to 11 ft Mississippi/Alabama border to the Alabama/Florida border, including Mobile Bay...6 to 9 ft Morgan City, Louisiana to the mouth of the Mississippi River...4 to 6 ft Alabama/Florida border to the Okaloosa/Walton County Line...4 to 6 ft Okaloosa/Walton County Line to Indian Pass, Florida...2 to 4 ft Indian Pass to Crystal River, Florida...1 to 3 ft The deepest water will occur along the immediate coast near and to the 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. RAINFALL: Nate is expected to produce the following rain accumulations through Monday: Western Cuba: 2 to 4 inches, max 6 inches. Cayman Islands: 1 to 3 inches. East of the Mississippi River from the central Gulf Coast into the Deep South, eastern Tennessee Valley, and southern Appalachians: 3 to 6 inches, max 10 inches. Across the Ohio Valley into the central Appalachians: 2 to 4 inches, max 6 inches. TORNADOES: A couple of tornadoes will be possible beginning late this afternoon over parts of the central Gulf Coast region. SURF: Swells generated by Nate will affect land areas around the Gulf of Mexico during the next day or so. 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 400 PM CDT. $$ Forecaster Beven