As of Oct. 10, Tropical Storm Delta has transitioned to a post-tropical cyclone as it continues to bring impacts to portions of the southern and eastern US. Forecast models indicate that Delta's remnants will bring thunderstorms with heavy rainfall, strong winds, and flooding across the southern and eastern US through at least Oct. 12. The affected areas include eastern Arkansas, far southeastern Missouri, southern Kentucky, Tennessee, northern Mississippi, Alabama, the Florida Panhandle, Georgia, South Carolina, southern North Carolina, western Virginia, eastern West Virginia, Maryland, and Washington, DC.
As of Oct. 10, the US National Weather Service (NWS) has issued tornado watches for far eastern Alabama and far western Georgia. Additionally, flash flood and flood watches are in effect for far northeastern Georgia and far western North Carolina. The Weather Prediction Center (WPC) has issued a "Slight Risk" (Level 2 of 4) of excessive rainfall for far eastern Arkansas, northern Mississippi, northern Alabama, western Tennessee, far northeastern Georgia, and western North Carolina over the coming days. Authorities with the Storm Prediction Center have issued a "Slight Risk" (Level 2 of 5) for severe weather across eastern Alabama and far western Georgia. Storms in the "Slight Risk" region are not forecast to be widespread or long-lived. Isolated intense storms are possible; however, widespread damage is unlikely. Authorities could issue new warnings throughout the system's progression in the coming days. Any new weather warnings that may be issued could remain active even after the system's immediate threat has diminished, as some areas may still be highly susceptible to rain-induced hazards.
Delta's remnants will continue to bring heavy rainfall, gusty winds, and high waves to portions of the southern and eastern US through at least Oct. 12. Forecast models indicate 7.5-15 cm (3-6 inches) of rainfall are possible in far northeastern Georgia, western North Carolina, western South Carolina, and western Virginia. Additionally, 2.5-7.5 cm (1-3 inches) of rainfall are possible from northern Alabama and the Tennessee Valley into the Mid-Atlantic region. Locally higher rainfall totals are possible in areas affected by persistent bands of thunderstorms.
Sustained heavy rainfall could trigger flooding in low-lying communities near streams, creeks, or rivers, as well as in 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.
In addition to the heavy rain and flooding, and despite weakening, the system is likely to produce tropical storm-force gusts in excess of 45 knots (85 kph, 50 mph) as it moves further inland. Widespread and prolonged power outages due to uprooted trees and toppled utility lines are possible; as of 1600 CDT, over 600,000 customers in Texas, Louisiana, and Mississippi remain without power. 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. Additionally, Delta's remnants will likely produce tornadoes, especially in Alabama, the Florida Panhandle, and western Georgia through at least early Oct. 11.
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 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.