Tropical Storm Helene formed over the Northwestern Caribbean Sea on Tuesday.  At 2:00 p.m. EDT on Tuesday the center of Tropical Storm Helene was located at latitude 19.4°N and longitude 84.5°W which put the center about 175 miles (280 km) south of the western tip of Cuba.  Helene was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 999 mb.

A Hurricane Watch is in effect for the portion of the coast from Indian Pass to Englewood, Florida.  The Hurricane Watch includes Tampa Bay.  A Hurricane Watch is in effect for the portion of the coast from Cabo Catoche to Tulum, Mexico.  The Hurricane Watch includes Cancun and Cozumel.  A Hurricane Watch is also in effect for the Cuban province of Pinar del Rio.

A Tropical Storm Warning is in effect for the Lower Florida Keys west of Seven Mile Bridge.  A Tropical Storm Warning is in effect for the Dry Tortugas.  A Tropical Storm Warning is in effect for the portion of the coast from Rio Lagartos to Tulum, Mexico.  The Tropical Storm Warning includes Cancun and Cozumel.  A Tropical Storm Warning was also in effect for the Cuban provinces of Artemisa, Pinar del Rio and Isle of Youth.

A Tropical Storm Watch is in effect for the Middle Florida Keys from Seven Mile Bridge to Channel 5 Bridge.  A Tropical Storm Watch is in effect for the portion of the coast from Englewood to Flamingo, Florida.  A Tropical Storm Watch is in effect for the portion of the coast from the Walton/Bay County Line to Indian Pass, Florida.

A U.S. Air Force Reserve Hurricane Hunter reconnaissance aircraft found that a low pressure system previously designated as Potential Tropical Cyclone Nine had strengthened over the Northwestern Caribbean Sea on Tuesday morning.  Based on data collected by the reconnaissance flight, the U.S. National Hurricane Center designated the system as Tropical Storm Helene.

The circulation around Tropical Storm Helene exhibited more organization on Tuesday.  The reconnaissance plane found a well defined low level center of circulation.  Even though the circulation around Helene was more organized, the distribution of thunderstorms was still asymmetrical.  Thunderstorms were occurring in bands in the eastern side of Tropical Storm Helene.  Bands in the western side of Helene consisted primarily of showers and lower clouds.  More thunderstorms were starting to develop in the bands in the western side of Helene’s circulation.  Storms near the center of Helene began to generate upper level divergence that pumped mass away from the tropical storm.

The distribution of wind speeds in Tropical Storm Helene was also asymmetrical.  Winds to tropical storm force extended out 140 miles (225 km) in the eastern side of Helene’s circulation.  The winds in the western side of Tropical Storm Helene were blowing at less than tropical storm force.

Tropical Storm Helene will move through an environment favorable for intensification during the next 24 hours.  Helene will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over the western Gulf of Mexico and the northwestern Caribbean Sea.   The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Storm Helene will intensify during the next 24 hours.  Helene is likely to strengthen to a hurricane by Wednesday morning.

Tropical Storm Helene will move around the western end of a high pressure system over the western Atlantic Ocean.  The high pressure system will steer Helene toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Helene will be near the northeastern tip of the Yucatan Peninsula on Wednesday morning.  Helene will move over the eastern Gulf of Mexico on Wednesday.  Helene is likely to approach northern Florida on Thursday afternoon.

Tropical Storm Helene is likely to be a hurricane when it reaches the northeastern tip of the Yucatan Peninsula.  Helene will bring strong winds and heavy rain to the northeastern part of the Yucatan Peninsula and to western Cuba.

Tropical Storm Helene could be a major hurricane when it approaches northern Florida on Thursday.  Helene will bring strong winds and heavy rain to northern Florida.  Heavy rain is likely to cause floods.  Helene could also cause a storm surge of up to 15 feet (4.5 meters) along portions of the coast of Florida.

A Storm Surge Watch is in effect for the portion of the coast from Indian Pass to Flamingo, Florida.  The Storm Surge Watch includes Tampa Bay and Charlotte Harbor.