Gulf of Mexico: TS Fred tracking north-northwestward early Aug. 15; landfall forecast near Pensacola, Florida, US early Aug. 17 /update 10

Event

Tropical Storm Fred continues to track north-northwestward in the Gulf of Mexico, north of Cuba early Aug. 15. As of 05:00 EDT Aug. 15, the storm's center of circulation was approximately 175 km (110 miles) west of the Dry Tortugas, Florida, US. Forecast models indicate the system will strengthen as it turns northward in the Gulf of Mexico and moves away from Cuba over the course of Aug. 15. Fred is then forecast to make another landfall as a tropical storm near Pensacola, Florida early Aug. 17. The system will subsequently weaken rapidly as it tracks northward across Alabama and will likely dissipate over the Alabama-Tennessee border by early Aug. 18. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

Government Advisories
As of 05:00 EDT Aug. 15, the following warnings and watches are in effect:

• Tropical Storm Watch: The Alabama-Florida border to Ochlockonee Florida

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

Hazardous Conditions
The storm will likely bring heavy rainfall, strong winds, and rough seas to coastal areas in Florida, Alabama, Georgia, North Carolina, and South Carolina through at least Aug. 17. 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 8-12.5 cm (3-5 inches) to parts of southern Florida and the Florida Keys through Aug. 16. 10-20 cm (4-8 inches) of rainfall is likely across the Florida Big Bend and Panhandle, while across south-central and southeast Alabama through Georgia and the Western Carolinas, 7.5-15 cm (3-6 inches) of rainfall can be expected through Aug. 17. Isolated greater rainfall totals are possible in Cuba, the Bahamas, and Florida. Torrential precipitation could trigger flash floods and mudslides. Heavy rains could begin impacting parts of the US Southeast and the southern and central Appalachians beginning Aug. 17 as the system moves inland.

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. The storm surge is forecast to raise water levels by 0.3-0.9 m (1-3 feet) above the normal tide from the mouth of the Pearl River, Louisiana, to the Suwannee River, Florida, including Mobile Bay, Pensacola Bay, Choctawhatchee Bay, and Saint Andrew Bay. 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 may be possible across parts of the west coast of Florida and the coastal Florida Panhandle through at least early Aug. 16.

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
Cuba Instituto de Meteorologia (Spanish)