Gulf of Mexico: Tropical Storm Elsa tracking northward in the Gulf of Mexico, west of the Florida Keys. July 6 /update 10

Event

Tropical Storm Elsa is tracking northward in the eastern Gulf of Mexico, west of the Florida Keys, US, July 6. As of 11:00 EDT, the storm's center of circulation was approximately 105 km (65 miles) west-northwest of Key West, Florida. Forecast models indicate the system will strengthen slightly and track northward along the western Florida coastline, making a close approach to Key West, Fla., early July 6 and Tampa, Fla., early July 7. Elsa will then likely begin tracking northeast and make landfall as a tropical storm in Levy County, Florida, early July 7.

After landfall, the system is forecast to weaken slightly as it tracks northeastwards across Florida July 7 and continues to South Carolina, early July 8. Elsa is forecast to track northeastwards across South Carolina and North Carolina and exit into the North Atlantic Ocean, late July 8. Elsa is likely to strengthen slightly and transition into a post-tropical cyclone with tropical storm strength winds and make landfall near Yarmouth, Nova Scotia, Canada, late July 9. The storm is forecast to continue track in a northeasterly direction across Nova Scotia and over Newfoundland through late July 10. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

Government Advisories
As of 11:00 EDT July 6, the following warnings and watches are in effect:

• Hurricane Watch: Egmont Key to the Steinhatchee River, Florida

• Tropical Storm Warning: Florida Keys from Craig Key westward to the Dry Tortugas, and the west coast of Florida from Flamingo to Ochlockonee River

• Tropical Storm Watch: Mouth of Saint Marys River to the Ochlockonee River, Florida

• Storm Surge Warning: West coast of Florida from Bonita Beach to the Aucilla River, including Tampa Bay

• Storm Surge Watch: West of the Aucilla River to the Ochlockonee River, Florida

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

A state of emergency has been declared for Alachua, Charlotte, Citrus, Collier, Columbia, Dixie, Franklin, Gilchrist, Hamilton, Hernando, Hillsborough, Jefferson, Lake, Lafayette, Lee, Levy, Madison, Manatee, Marion, Monroe, Pasco, Pinellas, Sarasota, Sumter, Suwannee, Taylor and Wakulla counties in Florida in advance of Tropical Storm Elsa. As of July 6, the Tampa International Airport (TPA) is closed beginning 17:00 EDT July 6 through at least early July 7. Additionally, Citrus and Hernando counties in Florida have issued voluntary evacuations in response to Tropical Storm Elsa.

Hazardous Conditions
Elsa will likely bring heavy rainfall, strong winds, and rough seas to western Cuba through at least the remainder of July 6, and Florida through at least July 7. 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 13-26 cm (5-10 inches) of rainfall across portions of Cuba, with isolated maximum amounts of 38 cm (15 inches). Across the Florida Keys into southwest and western portions of the Florida Peninsula will likely see 7.5-12.5 cm (3-5 inches) of rain, with localized maximum amounts up to 20 cm (8 inches). The rest of Florida is forecast to receive 5-10 cm (2-4 inches) of rainfall with localized maximum totals up to 15 cm (6 inches). Additionally, portions of southeastern Georgia and South Carolina could see 7.5-12.5 cm (3-5 inches) with localized maximum totals of up to 20 cm (8 inches). The coastal portions of North Carolina and into southeastern Virginia could see 2.5-7.5 cm (1-3 inches) of rain, with localized maximum amounts up to 13 cm (5 inches). The forecast heavy rainfall could trigger flash flooding and mudslides, potentially isolating some communities for several days.

Prolonged sea swells and storm surge generated by the system may result in coastal flooding. Forecasts predict storm surges of 0.9-1.5 meters (3-5 feet) for Englewood, Florida to Aucilla River including Tampa Bay. Additionally, 0.6-1.2 meters (2-4 feet) from Aucilla River to Ochlockonee River as well as Bonita Beach to Englewood, Florida including Charlotte Harbor. Storm surge totals of 0.3-0.9 meters (1-3 feet) are possible for Flamingo to Bonita Beach, Florida. Storm surge levls of 0.3-0.6 meters (1-2 feet) are forecast across Craig Key, Florida to Dry Tortugas as well as Ochlockonee River to Indian Pass and the mouth of the Saint Marys River to the South Santee River, South Carolina. 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, Elsa could produce damaging wind gusts, resulting in power outages due to fallen trees and toppled utility lines. Tornadoes are possible across Florida, southeastern Georgia, South Carolina, eastern North Carolina, and far southeastern Virginia through at least July 8.

Transport
In addition to the immediate threat to personal safety, inclement weather associated with the storm could trigger localized business, transport, and utility disruptions through July 6 across western Cuba, and July 7 across Florida US. 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)