Gulf of Mexico: Tropical Storm Elsa tracking north-northwest off southern US early July 6 /update 9

Event

Tropical Storm Elsa is tracking north-northwest in the eastern Gulf of Mexico, southwest of Florida, US, early July 6 after making landfall on the south coast of Cuba the afternoon of July 5. As of 02:00 EDT, the storm's center of circulation was approximately 80 km (50 miles) north of Havana, Cuba. Forecast models indicate the system will strengthen slightly and turn northward across the Florida Straits, making a close approach to Key West, Fla., US, early July 6 and Tampa, Fla., early July 7.

Elsa will then likely begin moving northeast and make landfall as a tropical storm near Gainesville, Fla., early July 7. After landfall, the system is forecast to weaken rapidly into a tropical depression 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 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 02:00 AST July 6, the following warnings and watches are in effect:

• Tropical Storm Warning: Matanzas, Mayabeque, Havana, and Artemisa provinces, Cuba; the Florida Keys from Craig Key west to Dry Tortugas, and the west coast of Florida from Flamingo to Ochlockonee River, US.

• Tropical Storm Watch: West of the Ochlockonee River to Indian Pass, Florida, US

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

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

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 Charlotte, Citrus, Collier, DeSoto, Hardee, Hernando, Hillsborough, Lee, Levy, Miami-Dade, Monroe, Pasco, Pinellas, and Sarasota counties in Florida in advance of Tropical Storm Elsa.

Authorities evacuated at least 180,000 people in Cuba in advance of the storm due to the risk of flooding. At least one death in Saint Lucia and two deaths in the Dominican Republic due to Tropical Storm Elsa have been reported, and at least 43 houses were damaged in Saint Vincent and the Grenadines. Barbados has been the most affected, with at least 1,100 houses suffering varying degrees of damage and 62 having completely collapsed. Crews are continuing to resolve widespread power outages; Grantley Adams International Airport (GAIA) has reopened.

Hazardous Conditions
Elsa will likely bring heavy rainfall, strong winds, and rough seas to the Cayman Islands and Cuba through July 6, and Florida through 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) through at least July 6. In the Cayman Islands, rainfall of 2.5-7.5 cm (1-3 inches) is forecast. 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) through July 7. The rest of Florida into southeast Georgia and the Low Country of South Carolina could see 5-10 cm (2-4 inches) of rainfall with localized maximum totals up to 15 cm (6 inches) through July 7. The coastal portions of South Carolina and North Carolina could see 2.5-7.5 cm (1-3 inches) of rain, with localized maximum amounts up to 13 cm (5 inches) through July 8. 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 the southern coast of Cuba, 0.9-1.5 meters (3-5 feet) for Englewood, Fla. to Aucilla River including Tampa Bay, 0.6-1.2 meters (2-4 feet) from Aucilla River to Ochlockonee River as well as Bonita Beach to Englewood including Charlotte Harbor, Fla., 0.3-0.9 meters (1-3 feet) for Flamingo to Bonita Beach, Fla., and 0.3-0.6 meters (1-2 feet) for Craig Key to Dry Tortugas, Fla. as well as Ochlockonee River to Indian Pass. 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 southern Florida through at least July 6.

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 in the Cayman Islands and Cuba, and July 7 in Florida. 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)
Dominican Republic Oficina Nacional de Meteorologia (Spanish)
Dominica Meteorological Service
Haiti Centre national de meteorologie (French)
Jamaica Meteorological Service