TD 25 Strengthens into Tropical Storm Gamma

A U.S. Air Force Reserve Hurricane Hunters’ reconnaissance plane found Friday evening that former Tropical Depression 25 had strengthened into Tropical Storm Gamma.  At 8:00 p.m. EDT on Friday the center of Tropical Storm Gamma was located at latitude 18.8°N and longitude 85.8°W which put it about 135 miles (220 km) southeast of Cozumel, Mexico.  Gamma was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1000 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Punta Herrero to Cabo Catoche, Mexico.  Tropical Storm Watches were in effect for the portions of the coast from Punta Herrero tp Puerto Costa Maya and from Cabo Catoche to Dzilam, Mexico.

A reconnaissance airplane found winds to tropical storm force and a lower minimum surface pressure when it started sampling former Tropical Depression Twentyfive.  The National Hurricane  Center upgraded the system to Tropical Storm Gamma based on data from the plane. The inner end of a rainband wrapped around the eastern and southern parts of the center of circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Storm Gamma.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the tropical storm.  The removal of mass allowed the surface pressure to decrease.

Tropical Storm Gamma will move through an environment favorable for intensification during the next 18 hours.  Gamma will move over water where the Sea Surface Temperature is near 30°C.  It will move under an upper level ridge over the Northwestern Caribbean Sea.  The upper level winds are weak in the middle of the ridge and there will be little vertical wind shear. Tropical Storm Gamma will strengthen during the next 18 hours and it could strengthen to a hurricane.

Tropical Storm Gamma will move around the southwestern part of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer the depression toward the northwest during the next 24 hours.  On its anticipated track Tropical Storm Gamma could approach the northeast coast of the Yucatan Peninsula on Saturday.  Gamma will bring gusty winds and heavy rain to the northern part of the Yucatan Peninsula.  Gusty winds and heavy rain could occur in the area around Cancun and Cozumel.  Locally heavy rain could cause flash floods in some locations.