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| #1059285 (Received by flhurricane at: 1:53 PM 29.Aug.2021) TCPAT4 BULLETIN Hurricane Ida Intermediate Advisory Number 14A NWS National Hurricane Center Miami FL AL092021 100 PM CDT Sun Aug 29 2021 ...EYE OF EXTREMELY DANGEROUS CATEGORY 4 HURRICANE IDA MOVING OVER SOUTHEASTERN LOUISIANA... ...CATASTROPHIC STORM SURGE, EXTREME WINDS, AND FLASH FLOODING IN PORTIONS OF LOUISIANA... SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...29.2N 90.3W ABOUT 20 MI...30 KM W OF GRAND ISLE LOUISIANA ABOUT 55 MI...90 KM SSW OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...150 MPH...240 KM/H PRESENT MOVEMENT...NW OR 320 DEGREES AT 13 MPH...20 KM/H MINIMUM CENTRAL PRESSURE...930 MB...27.46 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Intracoastal City Louisiana to the Alabama/Florida border * Vermilion Bay, Lake Borgne, Lake Pontchartrain, Lake Maurepas, and Mobile Bay A Hurricane Warning is in effect for... * Intracoastal City Louisiana to the Mouth of the Pearl River * Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans A Tropical Storm Warning is in effect for... * Cameron Louisiana to west of Intracoastal City Louisiana * Mouth of the Pearl River to the Alabama/Florida border A Storm Surge Warning means there is a danger of life-threatening inundation from rising water moving inland from the coastline 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 Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning 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 OUTLOOK ---------------------- At 100 PM CDT (1800 UTC), the eye of Hurricane Ida was located by NWS Doppler radar near latitude 29.2 North, longitude 90.3 West. Ida is moving toward the northwest near 13 mph (20 km/h), and a slightly slower northwestward motion should continue through this evening. A turn toward the north should occur by Monday morning, followed by a slightly faster northeastward motion by Monday night and Tuesday. On the forecast track, the center of Ida will move farther inland over southeastern Louisiana this afternoon and tonight. Ida is then forecast to move well inland over portions of Louisiana and western Mississippi Monday and Monday night, and move across the Tennessee Valley on Tuesday. Maximum sustained winds are near 150 mph (240 km/h) with higher gusts. Ida is an extremely dangerous category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Rapid weakening is expected during the next day or so, however Ida is forecast to remain a hurricane through late tonight. Hurricane-force winds extend outward up to 50 miles (85 km) from the center and tropical-storm-force winds extend outward up to 150 miles (240 km). A Florida Coastal Monitoring Observation Tower at South Lafourche Airport recently reported a sustained wind of 70 mph (113 km/h) and a wind gust of 102 mph (164 km/h). A sustained wind of 47 mph (60 km/h) and a gust of 63 mph (102 km/h) were recently reported at Lakefront Airport in New Orleans. A NOAA National Ocean Service tide gauge in Shell Beach, Louisiana, recently reported a water level of 6.8 feet above mean higher high water, which is an approximation of inundation in that area. The estimated minimum central pressure is 930 mb (27.46 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Ida can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4, WMO header WTNT44 KNHC, and on the web at hurricanes.gov/graphics_at4.shtml?key_messages. 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 could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Port Fourchon, LA to Mouth of the Mississippi River...12-16 ft Morgan City, LA to Port Fourchon, LA...8-12 ft Mouth of the Mississippi River to Bay St. Louis, MS including Lake Borgne...8-12 ft Bay St. Louis, MS to Ocean Springs, MS...5-8 ft Burns Point, LA to Morgan City, LA...5-8 ft Lake Pontchartrain...5-8 ft Ocean Springs, MS to MS/AL border...4-7 ft Lake Maurepas...4-6 ft East of Intracoastal City, LA to Burns Point, LA including Vermilion Bay...3-5 ft MS/AL border to AL/FL border including Mobile Bay...3-5 ft Rockefeller Wildlife Refuge, LA to Intracoastal City, LA...1-3 ft AL/FL border to Okaloosa/Walton County Line including Pensacola Bay...1-3 ft Overtopping of local levees outside of the Hurricane and Storm Damage Risk Reduction System is possible where local inundation values may be higher than those shown above. 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 dangerous 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: Catastrophic wind damage is likely near the core of Ida as it moves inland over southeastern Louisiana through this afternoon. Hurricane conditions will spread farther inland within the Hurricane Warning area over southeastern Louisiana through tonight. Tropical storm conditions will also spread inland over portions of Louisiana and Mississippi tonight and Monday. RAINFALL: Heavy rainfall from Ida will continue to impact the southeast Louisiana coast this morning, spreading northeast into the Lower Mississippi Valley later today into Monday. Total rainfall accumulations of 10 to 18 inches with isolated maximum amounts of 24 inches are possible across southeast Louisiana into far southern Mississippi through Monday. This is likely to result in life-threatening flash and urban flooding and significant riverine flooding impacts. Ida is forecast to turn to the northeast early Monday and track across the Middle Tennessee Valley and Upper Ohio Valley through Wednesday, producing the following rainfall totals: Coastal Alabama to the far western Florida panhandle: 5 to 10 inches with isolated maximum amounts of 15 inches, today through Tuesday morning. Central Mississippi: 4 to 8 inches with isolated maximum amounts of 12 inches, tonight through Monday night. Middle Tennessee Valley, Upper Ohio Valley, Central Appalachians into the Mid-Atlantic: 3 to 6 inches with isolated higher amounts, Tuesday into Wednesday. These rainfall totals will result in considerable flash and riverine flooding. TORNADOES: Tornadoes will be most likely through Monday over southeast Louisiana, southern Mississippi, southwest Alabama, and the western Florida Panhandle. A few tornadoes are also possible farther north across much of Mississippi and Alabama on Monday. SURF: Swells will affect the northern Gulf coast through early Monday. 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 Brown/Brennan |
