Tropical Storm Elsa Prompts Watch for Florida Keys

The forecast of the future track prompted the issuance of a Tropical Storm Watch for the Florida Keys from Craig Key to the Dry Tortugas on Saturday. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Elsa was located at latitude 17.9°N and longitude 75.3°W which put it about 175 miles (280 km) east-northeast of Montego Bay, Jamaica. Elsa was moving toward the west-northwest at 17 m.p.h. (28 km/h). The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 1004 mb.

Hurricane Watches were in effect for the Cuban provinces of Camaguey, Granma, Guantanamo, Holguin, Las Tunas and Santiago de Cuba. Tropical Storm Warnings were in effect for Jamaica and for the portion of the coast from Port Au Prince, Haiti to the southern border with the Dominican Republic. Tropical Storm Warnings were also in effect for the Cuban provinces of Camaguey, Granma, Guantanamo, Holguin, Las Tunas and Santiago de Cuba, Ciego de Avila, Sancti Spiritus, Cienfuegos, and Villa Clara. A Tropical Storm Watch was in effect for the Florida Keys from Craig Key to the Dry Tortugas. Tropical Storm Watches were also in effect for Cayman Brac, Little Cayman and the Cuban provinces of Matanzas, Mayabeque and Havana.

Tropical Storm Elsa looked impressive on infrared satellite images on Saturday night, but data from reconnaissance planes indicated that its circulation was not as well organized as it appeared to be. Very strong thunderstorms developed in bands east of the center of Elsa. Thunderstorms also increased in a band on the western periphery of the tropical storm. However the lower level center of circulation was still to the west of the center in the middle levels of the Tropical Storm Elsa. The lack of vertical alignment of the two centers was preventing Elsa from intensifying on Saturday evening. The strong thunderstorms east of the center were generating strong upper level divergence that was pumping mass away from the tropical storm. Winds to tropical storm force extended out 130 miles (210 km) from the center of Tropical Storm Elsa.

Tropical Storm Elsa will move through an environment somewhat favorable for intensification during the next 12 hours. Elsa will move over water where the Sea Surface Temperatures are near 30°C. Tropical Storm Elsa will move more slowly during the next 24 hours. If Elsa moves more slowly, there is a chance that the lower level and middle level centers could become vertically aligned. It will move into a region where the upper level winds are weak and there will be less vertical wind shear. Tropical Storm Elsa could intensify back to a hurricane before it reaches Cuba on Sunday.

Tropical Storm Elsa will move south of the subtropical high pressure system over the Atlantic Ocean during the next 12 hours. The high will continue to steer Tropical Storm Elsa toward the west-northwest, but Elsa is likely to move more slowly. An upper level trough over the eastern U.S. is forecast to weaken the western end of the high pressure system on Sunday. When the high weakens, then Tropical Storm Elsa will move more toward the northwest. On its anticipated track the center of Tropical Storm Elsa will pass just to the north of Jamaica. Elsa could be near eastern Cuba by Sunday morning. Tropical Storm Elsa could approach the Florida Keys on Monday. Elsa will cause gusty winds and locally heavy rain over parts of Haiti, Jamaica and Cuba.