- Incident: Hurricane Delta
- Location(s): Yucatan Peninsula, Mexico, southern and eastern US (map)
- Projected Landfall (Date): South-central or southwestern Louisiana, US (late Oct. 9 or early Oct. 10)
- Center of Circulation: Approximately 130 km (80 miles) north-northeast of Merida, Yucatan, Mexico
- Maximum Sustained Winds: 75 knots (140 kph, 85 mph)
Hurricane Delta has weakened considerably after making landfall in the Yucatan Peninsula near Playa del Carmen, Quintana Roo, Mexico, Oct. 7. As of 1600 CDT, the system's center of circulation was in the Gulf of Mexico approximately 130 km (80 miles) north-northeast of Merida, Yucatan. Forecast models indicate Delta will continue to track northwestward in the warm waters of the Gulf of Mexico, which will allow it to re-strengthen to a category-3 hurricane by Oct. 9. Impacts will likely be felt in portions of the Gulf Coast US beginning Oct. 9; the latest forecast guidance indicates that landfall is most likely in south-central or southwestern Louisiana between late Oct. 9 and early Oct. 10. This represents a westward shift from previous guidance. Following landfall, the system will rapidly weaken as it tracks across the US Gulf Coast region. Delta's remnants will likely bring heavy rainfall to portions of the eastern US, including the Southeast, Tennessee Valley, and Ohio Valley regions through at least Oct. 12. Significant uncertainty remains in the track and intensity forecast, and changes could occur over the coming days, especially regarding potential impacts and landfall along the Gulf Coast of the US.
As of 1600 CDT Oct. 7, the following warnings are in effect in response to the storm:
- Hurricane Warning: Tulum to Dzillam, Mexico, and Cozumel, Mexico
- Hurricane Watch: High Island, Texas to Grand Isle, Louisiana
- Tropical Storm Warning: Dzilam to Progreso, Mexico
- Tropical Storm Watch: San Luis Pass to west of High Island, Texas; east of Grand Isle, Louisiana to Bay St. Louis, Mississippi, including New Orleans; Lake Pontchartrain and Lake Maurepas
Authorities could issue new warnings or update/rescind existing advisories throughout the system's progression in the coming days. Weather warnings could remain active even after the system's immediate threat has diminished, as some areas may still be highly susceptible to rain-induced hazards. The possibility of localized evacuations cannot be discounted if weather conditions prove particularly hazardous. The proximity of the system's center of circulation to land will ultimately determine how significant the weather-related impacts will be; the greatest impacts will likely be felt just northeast of where the center passes.
In advance of Delta, Quintana Roo Governor Carlos Joaquin issued evacuation warnings for Isla Holbox, Punta Allen, Cancun's Hotel Zone, the tents of the Kumate Hospital in Cancun, Puerto Morelos, Punta Herrero, Maria Elena Island, and Banco Chinchorro. In Cuba, coastal areas of Pinar de Rio province are under evacuation orders. In the US, a state of emergency is in effect in Alabama and mandatory evacuations have been issued for Dauphin Island, Fort Morgan, Orange Beach, Gulf Shores, and Ono Island. A state of emergency has also been issued in Louisiana, and voluntary evacuation orders are in place for portions of Acadia, Iberia, Lafayette, Lafourche, Plaquemines, Saint Martin, and Saint Mary's parishes. Mandatory evacuations are in place for Vermillion and Jefferson parishes.
Hurricane Delta will continue to bring heavy rainfall, gusty winds, and high waves to portions of far southeastern Mexico through Oct. 8 before impacting the Gulf Coast of the US beginning Oct. 9. Widespread rain accumulations around 10-15 cm (4-6 inches) are forecast across the northern Yucatan Peninsula. Locally higher rainfall totals up to 25 cm (10 inches) are possible in areas affected by persistent bands of thunderstorms. Rainfall totals of 10-20 cm (4-8 inches) are expected in the central Gulf Coast region northward into the Mississippi Valley, with higher totals of up to 30 cm (12 inches) possible where the most persistent heavy rain bands occur. Heavy rainfall is also expected in portions of the Tennessee Valley and Ohio Valley, Oct. 11-12.
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. Prolonged swells and storm surge generated by the system will likely result in coastal flooding as the system approaches the islands. A persistent onshore flow could make it difficult for the surge to recede, and water levels decrease in coastal river catchments.
The greatest impacts in terms of strong winds and storm surge will be felt just to the east of the center of circulation relative to the storms track. This is partly due to the counterclockwise circulation of a hurricane in the northern hemisphere, which allows for a higher storm surge because the winds help bring additional water on to the shore. Forecast models indicate life-threatening storm surge totals of 2.1-3.4 meters (7-11 feet) are expected from Pecan Island, Louisiana to Port Fourchon, Louisiana including Vermilion Bay; surge of 1.2-2.1 meters (4-7 feet) is expected from Cameron, Louisiana to Pecan Island, Louisiana, as well as Port Fourchon, Louisiana to Ocean Springs, Mississippi including Lake Borgne. Surge of 0.6-1.5 meters (2-5 feet) is forecast in Lake Pontchartrain and Lake Maurepas, from Ocean Springs, Mississippi to the Alabama/Florida border including Mobile Bay, and from High Island, Texas to Cameron, Louisiana including Calcasieu Lake. Minor storm surge is also possible in Galveston Bay, Texas.
In addition to the heavy rain, flooding, and storm surge, the system is likely to produce damaging wind gusts as its center approaches the Gulf Coast of the US. Hurricane-force gusts over 90 knots (165 kph, 100 mph) are possible along the Gulf Coast of the US near where the center of Delta makes landfall, including south-central and southwestern Louisiana; tropical-storm-force gusts in excess of 45 knots (85 kph, 50 mph) cannot be ruled out farther inland as well as in far southeastern Texas and southeastern Louisiana. Widespread and prolonged power outages due to uprooted trees and toppled utility lines are possible. Rain-induced landslides are also possible in hilly areas where the ground is loose and unstable, especially in areas where heavy rainfall occurred during previous tropical systems, including Hurricane Laura. Additionally, Hurricane Delta is likely to produce tornadoes as it approaches the US.
In addition to the immediate threat to personal safety, inclement weather associated with the storm could trigger localized business, transport, and utility disruptions over the coming days. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel 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 conditions have improved. If there is severe damage to infrastructure, repair, or reconstruction efforts may exacerbate residual disruptions.
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 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 weeks. Keep any necessary medications in a waterproof container.
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.
Visit the Hurricane Delta Risk Intelligence & Readiness Resource Center for all storm-related alerts, readiness resources, and other expert insights.