27 Aug 2021 | 11:44 PM UTC
Caribbean Sea: Hurricane Ida moves through northwestern Caribbean Sea and approaches Gulf of Mexico Aug. 27 /update 2
Hurricane Ida makes landfall on Isla de la Juventud, Cuba, and nears Gulf of Mexico Aug. 27; landfall forecast in Louisiana, US, Aug. 29.
Event
Hurricane Ida has made landfall over Cuba's Isla de la Juventud and is forecast to make landfall in western mainland Cuba late Aug. 27 before moving into the Gulf of Mexico. As of 17:00 EDT Aug. 27, the system's center of circulation was approximately 70 km (45 miles) northwest of Isla de la Juventud and about 145 km (90 miles) southwest of Havana.
Forecast models indicate the system will continue to strengthen and move northwestward across the Gulf of Mexico from late Aug. 27 through Aug. 28 until it approaches the US Gulf Coast Aug. 29. Ida is forecast to make landfall as a Category 4 hurricane in coastal Louisiana Aug. 29. After landfall, the storm is likely to weaken rapidly as it turns to track northward and then northeastward, transiting over southern Louisiana and much of Mississippi through the early afternoon hours of Aug. 31. The system is then forecast to transition into a post-tropical cyclone by early afternoon of Sept. 1 as it tracks over Tennessee. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.
Authorities have issued a state of emergency for Louisiana in advance of the storm. Mandatory evacuation orders are in effect in Plaquemines Parish along the entire East Bank as well as along the parish's West Bank from the Phillips 66 Alliance Refinery to Venice. Areas of Orleans Parish, including New Orleans, that lie outside of the levee protection system are likewise under a mandatory evacuation order, as is Grand Isle. Other areas along the coast of Louisiana are also under voluntary or mandatory evacuation orders, including the low-lying areas of Lafourche Parish, Port Fourchon, Barataria, Crown Point, Jean Lafitte, and Lower Lafitte. Voluntary evacuation orders may be upgraded to mandatory orders as the storm nears.
Government Advisories
As of 17:00 EDT Aug. 27, authorities have issued watches and warnings for the following areas:
Hurricane Warning: the Cuban provinces of Artemisa and Pinar del Rio, as well as Isla de la Juventud; Intracoastal City, Louisiana, to the mouth of the Pearl River; Lake Pontchartrain, Lake Maurepas, and metropolitan New Orleans, La.
Hurricane Watch: Cameron, La., to west of Intracoastal City, La.; mouth of the Pearl River to the Mississippi-Alabama border.
Tropical Storm Warning: Cuban provinces of Matanzas, Mayabeque, and Havana; Cameron, La., to west of Intracoastal City, La.; mouth of the Pearl River to the Mississippi-Alabama border.
Tropical Storm Watch: Mississippi-Alabama border to the Alabama-Florida border.
Storm Surge Warning: east of Rockefeller Wildlife Refuge, La., to the Mississippi-Alabama border; Vermilion Bay, Lake Borgne, Lake Pontchartrain, and Lake Maurepas, La.
Storm Surge Watch: Sabine Pass to Rockefeller Wildlife Refuge, La.; Mobile Bay.
Officials are likely to modify or issue additional warnings and/or watches in response to the developing system in the coming hours and days.
Hazardous Conditions
Hurricane Ida will likely bring heavy rainfall and strong winds to areas in the path of the storm through at least Sept. 1. Ida is also likely to bring rough seas to affected coastal areas through at least Aug. 29. Sustained heavy rainfall could trigger flooding in low-lying communities near streams, creeks, rivers, and urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs could experience flash flooding after relatively short periods of intense rainfall. Flooding could isolate some communities for several days. Forecasts indicate the system may bring 15-25 cm (6-10 inches) of rainfall to areas across Jamaica, and 20-30 cm (8-12 inches) of rainfall across the Cayman Islands, Isla de la Juventud, and western Cuba. Locally higher totals are possible.
As Ida approaches the US, the storm will likely bring 20-41 cm (8-16 inches) of rainfall from southeastern Louisiana to coastal Mississippi and Alabama through early Aug. 30; isolated maximum totals of up to 51 cm (20 inches) of rainfall are possible. Rainfall totals of 10-20 cm (4-8 inches) are possible across southern and central Mississippi into the Tennessee Valley.
Prolonged sea swells and storm surge generated by the system will likely result in coastal flooding as the system approaches land. Persistent onshore flow could make it difficult for the surge to recede and for water levels to decrease in coastal river catchments. In addition to the heavy rain, flooding, and storm surge, the storm could produce damaging wind gusts, resulting in power outages due to uprooted trees and toppled utility lines.
The system threatens to bring a dangerous storm surge to parts of the US Gulf Coast during high tide (i.e., up to 3-4.5 meters [10-15 feet) above ground from Morgan City, La., to the mouth of the Mississippi River, and lesser heights in other areas along the Gulf Coast); the surge will likely cause major coastal flooding. The deepest water will occur along the coastline near and to the east of the location of the storm's landfall, where the surge will likely be accompanied by large and dangerous waves.
Transport
Inclement weather associated with the storm could trigger localized business, transport, and utility disruptions in coastal areas of Jamaica, the Cayman Islands, Cuba, the Yucatan Peninsula, and the Southern US over the coming days. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Areal flooding in urban locations could also result in severe traffic congestion, while strong winds will pose a hazard to high-profile vehicles. Heavy rain and low visibility may trigger flight disruptions at regional airports.
Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after weather conditions have improved. If there is severe damage to infrastructure, repair or reconstruction efforts may exacerbate residual disruptions.
Advice
Activate contingency plans in areas where officials forecast hurricane or tropical storm conditions. Heed all evacuation orders. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the high potential for severe flooding and storm surge. Stockpile water, batteries, and other essentials in advance. Charge battery-powered devices when electricity is available; restrict the use of cellular phones to emergencies only. Power down mobile devices when not in use. Keep important documents and necessary medications in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming days.
Plan accordingly for protracted commercial, transport, and logistics disruptions in areas in the path of the storm, especially if vital infrastructure is damaged. Seek updated information on road conditions before driving or routing shipments through areas where flooding has occurred. Confirm flights before checking out of hotels or driving to the airport; clearing passenger backlogs may take several days in some locations.
