US: Tropical Depression Fred tracking north-northeastward over southwestern Georgia early Aug. 17 /update 14

Event

Tropical Depression Fred is tracking north-northeastward over southwestern Georgia early Aug. 17. As of 04:00 CDT Aug. 17, the storm's center of circulation was approximately 25 km (15 miles) south-southwest of Columbus, Georgia. Forecast models indicate the system will weaken as it tracks across western and northern Georgia Aug. 17 before tracking across the southern and central Appalachian Mountains late Aug. 17 and into the central Appalachians by early Aug. 18. Fred is forecast to dissipate in northern West Virginia, near the West Virginia-Pennsylvania border, by afternoon Aug. 13. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

Government Advisories
As of 04:00 CDT Aug. 17, the Storm Prediction Center (SPC) has issued a "Slight Risk" (Level 2 on a 5-tier scale) for severe weather for northeastern Georgia, western North Carolina, western South Carolina, and southwestern Virginia through early Aug. 18.

The Weather Prediction Center (WPC) has issued a "High Risk" for excessive rainfall for southwestern North Carolina, where the heaviest rainfall is forecast. A "Moderate Risk" for excessive rainfall is in place for northeastern Georgia, western North Carolina, and northwestern South Carolina, while a "Slight Risk" for excessive rainfall has been issued for northern Georgia, eastern Kentucky, northern Florida, western Maryland, southern New York, western and eastern North Carolina, far southeastern Ohio, most of Pennsylvania, most of South Carolina, eastern Tennessee, western Virginia, and West Virginia through at least early Aug. 19. Additionally, flood and flash flood watches and warnings are in place for northern Georgia, far eastern Kentucky, western North Carolina, western South Carolina, eastern Tennessee, western Virginia, and southern West Virginia. A tornado watch is in place for northern Georgia through at least 13:00 EDT Aug. 17.

Officials could issue new warnings and/or watches in response to the system in the coming hours.

Hazardous Conditions
The storm will likely bring heavy rainfall and strong winds to areas in western Florida, Alabama, western Georgia, eastern Tennessee, eastern Kentucky, western Virginia, West Virginia, western Pennsylvania, eastern Ohio, western North Carolina, and South Carolina through at least Aug. 18. 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. Forecast models indicate the system will likely bring rainfall totaling 10-20 cm (4-8 inches) across portions of Georgia and the Southern Appalachians and 5-10 cm (2-4 inches) of rain to the central Appalachians, including portions of the Mid-Atlantic states. Torrential precipitation could trigger flash floods and mudslides. There is a risk of landslides across the North Carolina mountains and portions of the Blue Ridge Escarpment through Aug. 17.

Prolonged sea swells and storm surge generated by the system may result in coastal flooding. 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 fallen trees and toppled utility lines. Tornadoes are possible across parts of Georgia, the western Carolinas, and southwestern Virginia through late Aug. 17.

Transport
In addition to the immediate threat to personal safety, inclement weather associated with the storm could trigger localized business, transport, and utility disruptions in areas impacted by the system. 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 adverse 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.

Resources

US National Hurricane Center
National Weather Service