TD 4E Strengthens to Tropical Storm Carlotta

Tropical Depression Four-E strengthened to Tropical Storm Carlotta south of Mexico on Friday afternoon.  At 2:00 p.m. EDT on Friday the center of Tropical Storm Carlotta was located at latitude 16.0°N and longitude 99.4°W which put it about 60 miles (95 km) south-southeast of Acapulco, Mexico.  Carlotta was moving toward the northeast at 5 m.p.h. (8 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 1006 mb.  A Tropical Storm Warning was in effect for the portion of the coast from Tecpan de Galeana to Lagunas de Chacahua, Mexico.

A single, distinct center of circulation developed in Tropical Depression Four-E on Friday afternoon and the National Hurricane Center designated the system as Tropical Storm Carlotta.  It is possible that the mountains in Mexico deflected the circulation in the lower levels and contributed to the improved organization of Tropical Storm Carlotta.  Stronger thunderstorms were forming near the center of circulation.  A primary band of showers and thunderstorms developed east and south of the core of Carlotta.  Other rainbands were revolving around the core of the tropical storm.  Storms in the core were generating upper level divergence and Carlotta looked like a tropical storm on satellite images.

Tropical Storm Carlotta will remain in an environment favorable for intensification while the center is over water.  The Sea Surface Temperature of the water south of Mexico is near 30°C.  The upper level winds are weak in that area and there is little vertical wind shear.  Carlotta could strengthen further during the next 12 hours.  When the center nears the coast of Mexico, the circulation could begin to pull in drier air from over the land.  If that happens, then Tropical Storm Carlotta could start to weaken even before the center officially makes landfall.

The steering winds are weak around Tropical Storm Carlotta.  A trough in the lower levels is moving across the southwestern Gulf of Mexico and it appears to be pulling Carlotta slowly toward the northeast.  On its anticipated track the center of Tropical Storm Carlotta will reach the coast of Mexico in 12 to 18 hours.  Tropical Storm Carlotta is expected to make landfall east of Acapulco.  Carlotta will produce some gusty winds but the greater risks are heavy rain and flash floods.

Elsewhere, Tropical Depression Bud is moving over the Gulf of California.  At 11:00 a.m. EDT on Friday the center of Tropical Depression Bud was located at latitude 25.3°N and longitude 110.0°W which put it about 70 miles (110 km) west of Los Mochis, Mexico.  Bud was moving toward the north at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1002 mb.  Bud could drop heavy rain and cause flash floods in the states of Sinaloa, Sonora and Chihuahua.