000 WTNT34 KNHC 290248 TCPAT4  BULLETIN Hurricane Ida Advisory Number  11 NWS National Hurricane Center Miami FL       AL092021 1000 PM CDT Sat Aug 28 2021  ...IDA FORECAST TO STRENGTHEN RAPIDLY BEFORE LANDFALL... ...LIFE-THREATENING STORM SURGE, POTENTIALLY CATASTROPHIC WIND DAMAGE, AND FLOODING RAINFALL EXPECTED TO IMPACT THE NORTHERN GULF COAST BEGINNING SUNDAY MORNING...   SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...27.2N 88.0W ABOUT 145 MI...235 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER ABOUT 235 MI...375 KM SE OF HOUMA LOUISIANA MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H PRESENT MOVEMENT...NW OR 325 DEGREES AT 16 MPH...26 KM/H MINIMUM CENTRAL PRESSURE...964 MB...28.47 INCHES   WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY:  None.  SUMMARY OF WATCHES AND WARNINGS IN EFFECT:  A Storm Surge Warning is in effect for... * East of Rockefeller Wildlife Refuge 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, 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 Hurricane Warning means that hurricane conditions are expected somewhere within the warning area.  A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.  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 within 36 hours.  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 1000 PM CDT (0300 UTC), the center of Hurricane Ida was located near latitude 27.2 North, longitude 88.0 West. Ida is moving toward the northwest near 16 mph (26 km/h), and this general motion should continue through late Sunday or early Monday, followed by a slower northward motion on Monday.  A northeastward turn is forecast by Monday night.  On the forecast track, the center of Ida will continue moving across the central and northern Gulf of Mexico tonight and early Sunday, and make landfall along the coast of Louisiana within the hurricane warning area Sunday afternoon or evening. Ida is then forecast to move well inland over portions of Louisiana and western Mississippi on Monday and Monday night.  Maximum sustained winds are near 105 mph (165 km/h) with higher gusts.  Rapid strengthening is forecast during the next 12 to 18 hours and Ida is expected to be an extremely dangerous major hurricane when it makes landfall along the Louisiana coast on Sunday.  Rapid weakening is expected after landfall.  Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km).  The estimated minimum central pressure based on data from the NOAA Hurricane Hunter aircraft is 964 mb (28.47 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...  Morgan City, LA to Mouth of the Mississippi River...10-15 ft Mouth of the Mississippi River to Ocean Springs, MS including Lake Borgne...7-11 ft Burns Point, LA to Morgan City, LA...6-9 ft Lake Pontchartrain...5-8 ft Ocean Springs, MS to MS/AL border...4-7 ft Intracoastal City, LA to Burns Point, LA including Vermilion Bay...4-6 ft Lake Maurepas...4-6 ft Pecan Island, LA to Intracoastal City, LA...2-4 ft MS/AL border to AL/FL border including Mobile Bay...2-4 ft Sabine Pass to Pecan Island, LA...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:  Hurricane conditions are expected in the hurricane warning area along the Louisiana coast beginning Sunday with tropical storm conditions expected to begin later tonight or early Sunday morning.  These conditions will spread inland over portions of Louisiana and Mississippi Sunday night and Monday.  RAINFALL:   Heavy rainfall from Ida will begin to impact the Louisiana coast Sunday morning, spreading northeast into the Lower Mississippi Valley later Sunday into Monday.  Total rainfall accumulations of 8 to 16 inches with isolated maximum amounts of 20 inches are possible across southeast Louisiana into southern Mississippi through Monday. This is likely to result in life-threatening flash and urban flooding and significant riverine flooding impacts.  Elsewhere across eastern Louisiana, Mississippi, far southwestern Alabama and the Middle Tennessee Valley -- considerable flash and riverine flooding impacts are likely on Monday and Tuesday, with rainfall totals of 4 to 8 inches possible. Rainfall from Ida will begin to affect the Ohio Valley by mid-week, resulting in flash and riverine flooding impacts.  TORNADOES:  Tornadoes will be possible Sunday into Monday across eastern Louisiana, Mississippi, central and southern Alabama, and the Florida Panhandle.  SURF:  Swells are beginning to reach the northern Gulf coast and will continue to affect that area through 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 intermediate advisory at 100 AM CDT. Next complete advisory at 400 AM CDT.  $$ Forecaster Cangialosi