1. Life-threatening storm surge and hurricane conditions are expected later today and tonight in portions of western Cuba, including the Isle of Youth, where a Hurricane Warning is in effect. Life-threatening heavy rains, flash flooding and mudslides are expected across Jamaica, the Cayman Islands, and western Cuba, including the Isle of Youth.

2. The risk of life-threatening storm surge inundation is increasing along the coasts of Louisiana, Mississippi, and Alabama. Inundation of 7 to 11 feet above ground level is possible within the area from Morgan City, Louisiana, to Ocean Springs, Mississippi, including Lake Borgne. Interests in these areas should follow any advice given by local officials.

3. Ida is expected to be a dangerous major hurricane when it reaches the northern Gulf Coast on Sunday, and the risk of hurricane-force winds continues to increase, especially along portions of the Louisiana coast, including metropolitan New Orleans. Potentially devastating wind damage could occur where the core of Ida moves onshore.

4. Ida is likely to produce heavy rainfall later Sunday into Monday across the central Gulf Coast from southeast Louisiana to coastal Mississippi and Alabama, as well as the Lower Mississippi Valley, resulting in considerable flash, urban, small stream, and riverine flooding.

CHANGES WITH THIS ADVISORY: The government of Cuba has replace the Tropical Storm Warning with a Hurricane Warning for the Isle of Youth, and the Cuban provinces of Pinar del Rio and Artemisa. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for...
- Cuban provinces of Pinar del Rio and Artemisa, and the Isle of Youth A Storm Surge Watch is in effect for...
- Sabine Pass to Alabama/Florida border
- Vermilion Bay, Lake Borgne, Lake Pontchartrain, Lake Maurepas, and Mobile Bay A Hurricane Watch is in effect for...
- Cameron, Louisiana to the Mississippi/Alabama border
- Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans A Tropical Storm Warning is in effect for...
- Little Cayman and Cayman Brac
- Cuban provinces of Matanzas, Mayabeque, and Havana A Tropical Storm Watch is in effect for...
- Mississippi/Alabama border to the Alabama/Florida border. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area, in this case within the next 12 hours. 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 watch is typically issued 48 hours before the anticipated first occurrence of tropical storm force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. Interests elsewhere in central and western Cuba and elsewhere along the northern U.S. Gulf coast should monitor the progress of this system. Hurricane warnings will likely be required for portions of the northern Gulf coast later today. Interests in the Dry Tortugas should also monitor the progress of Ida. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service.

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: A dangerous storm surge will raise water levels by as much as 4 to 6 feet above normal tide levels in areas of onshore winds along the immediate coast of the Isle of Youth and near and to the east of where the center crosses the coast of western Cuba. Near the coast, the surge will be accompanied by large and destructive waves. 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 Ocean Springs, MS including Lake Borgne...7 11 ft Rockefeller Wildlife Refuge, LA to Morgan City, LA including Vermilion Bay...4 7 ft Ocean Springs, MS to MS/AL border...4 7 ft MS/AL border to AL/FL border including Mobile Bay...3 5 ft Lake Pontchartrain...4 6 ft Lake Maurepas...3 5 ft Sabine Pass to Rockefeller Wildlife Refuge, LA...2 4 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: Tropical storm conditions are expected on Little Cayman and Cayman Brac through early this afternoon. Hurricane conditions are expected to reach the Isle of Youth and portions of western Cuba in the Hurricane Warning area by later this afternoon and evening, with tropical storm conditions beginning within the next couple of hours on the Isle of Youth.

Hurricane conditions are possible in the hurricane watch area along the northern Gulf coast late Saturday night or Sunday and tropical storm conditions are possible in the watch area late Saturday night or Sunday.

RAINFALL: Ida is expected to produce total rainfall accumulations of 6 to 10 inches with maximum totals of 15 inches across Jamaica. Rainfall totals of 8 to 12 inches with isolated maximum amounts of 20 inches are expected across the Cayman Islands and western Cuba, including the Isle of Youth. These rainfall amounts may produce life threatening flash floods and mudslides. As Ida approaches the central Gulf Coast Sunday afternoon, total rainfall accumulations of 8 to 16 inches with isolated maximum amounts of 20 inches are possible from southeast Louisiana to coastal Mississippi and Alabama through Monday morning. Ida is forecast to turn northeast as it moves inland later Monday with rainfall totals of 4 to 8 inches possible across southern and central Mississippi. This is likely to result in considerable flash, urban, small stream, and riverine flooding.

SURF: Swells generated by this system will affect the Cayman Islands and Cuba through tonight. Swells will begin reaching portions of the northern Gulf coast Saturday night or early Sunday. These swells are likely to cause life threatening surf and rip current conditions. Please consult products from your local weather office.

At 1100 AM EDT (1500 UTC), the center of Tropical Storm Ida was located near latitude 20.7 North, longitude 82.1 West. Ida is moving toward the northwest near 15 mph (24 km/h), and this general motion should continue over the next few days. On the forecast track, the center of Ida will pass near or over the Isle of Youth and western Cuba later today, and move over the southeastern and central Gulf of Mexico tonight and Saturday. Ida is forecast to make landfall along the U.S. northern Gulf coast within the hurricane watch area on Sunday. Reports from Air Force and NOAA reconnaissance aircraft indicate that the maximum sustained winds have increased to near 65 mph (100 km/h) with higher gusts. Additional strengthening is forecast today and Ida is expected to be a hurricane when it nears western Cuba later today. Steady to rapid strengthening is expected when Ida moves over the southeastern and central Gulf of Mexico over the weekend, and Ida is expected to be a major hurricane when it approaches the northern Gulf coast. Tropical storm force winds extend outward up to 90 miles (150 km) from the center. A wind gust to 45 mph (72 km/h) was recently reported on Cayman Brac and a wind gust to 41 mph (67 km/h) has been observed on Cayo Largo, Cuba, within the past hour or two. The latest minimum central pressure reported by an Air Force Reserve reconnaissance aircraft is 996 mb (29.42 inches).

Radar imagery from Grand Cayman and Cuba as well as satellite data continue to show an improvement in Ida's overall structure this morning, with an increase in banding, the development of a small central dense overcast, and more recently an improved inner-core feature. Both the NOAA and Air Force reconnaissance aircraft reported that the pressure has fallen to around 996 mb, and the Air Force plane has measured flight-level and SFMR winds that support an initial intensity of 55 kt.

Although there is still some southwesterly shear over Ida, the outflow has begun to expand over the northeastern and southeastern portions of the circulation. The upper-level trough near the Yucatan peninsula that has been imparting the shear over Ida is forecast to weaken and move westward during the next 12 to 24 hours, which should result in a more favorable upper-level wind pattern. This, in combination with warm sea surface temperatures and a moist environment along the forecast track of the storm are expected to result in steady to rapid strengthening. Ida is now foreast to become a hurricane when it is near western Cuba and once it moves over the southeastern Gulf of Mexico a period of rapid strengthening is likely to begin, with the NHC intensity forecast explicitly calling for rapid intensification to major hurricane strength between 24 and 48 hours. The official intensity forecast is on the higher side of the intensity guidance but not quite as high as the slightly more aggressive CTCI, HWRF, and HCCA models. In addition to the increase in strength, the dynamical model guidance indicates that Ida's wind field will grow larger as it moves over the Gulf of Mexico and this is reflected in the NHC wind radii forecast. In summary, there is a higher-than-normal confidence that a significant hurricane will impact a large portion of the northern Gulf coast by late this weekend and early next week.

Ida is moving northwestward or 320/13 kt. The track forecast reasoning is unchanged from before. A mid-level ridge over the western Atlantic is forecast to move westward and this should keep Ida on a general northwestward heading during the next 48-60 hours. This track will bring the storm across western Cuba later today, over the southeastern and central Gulf of Mexico on Saturday and Saturday night, to the coast of Louisiana by late Sunday. The track guidance is in remarkably good agreement with very little cross-track spread during the first 60 hours or so of the forecast period. After that time, Ida is forecast to reach the western portion of the ridge, which is expected to cause the storm to slow down and turn northward and then northeastward over the southeastern United States. The NHC track forecast is near or just east of the various consensus aids, in best agreement with the GFS ensemble mean. Although the small spread in the guidance through landfall increases the overall confidence in the track forecast, users are reminded to not focus on the exact details of the forecast track as storm surge, wind, and rainfall impacts will extend far from the center.