Tropical Storm Sally Prompts Hurricane Watch for Gulf Coast

Expected intensification of Tropical Storm Sally prompted the National Hurricane Center to issue a Hurricane Watch for a portion of the Gulf Coast.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Sally was located at latitude 25.7°N and longitude 81.9°W which put it about 30 miles (50 km) south-southwest of Naples, Florida.  Sally was moving toward the west at 7 m.p.h. (11 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 1004 mb.

A Hurricane Watch was issued for the portion of the coast from Grand Isle, Louisiana to the Alabama/Florida border including New Orleans, Lake Pontchartrain and Lake Maurepas.  A Tropical Storm Watch was in effect for the portion of the coast from the Ochlockonee River, Florida to the Alabama/Florida Line.

The circulation around Tropical Storm Sally continued to get better organized on Saturday afternoon as it moved slowly away from Southwest Florida.  Bands of showers and thunderstorms strengthened in the eastern half of Sally and the strongest winds were occurring in those bands.  Bands in the western half of the tropical storm consisted primarily of showers and lower clouds.  Storms near the center of circulation began to generate upper level divergence which pumped mass away from the tropical storm.  Winds to tropical storm force extended out 80 miles (130 km) southeast of the center of Tropical Storm Sally.  Winds in the other parts of the circulation were blowing at less than tropical storm force.

Tropical Storm Sally will move through an environment favorable for intensification during the next 48 hours.  Sally will move over water where the Sea Surface Temperature is near 30°C.  It will move under an upper level ridge where the winds are weak and there will be little vertical wind shear.  Tropical Storm Sally will intensify and it could strengthen into a hurricane by Monday.  Once an inner core forms, Sally could intensify rapidly and there is a chance it could strengthen into a major hurricane.  The environment will not be as favorable for rapid intensification as it was for Hurricane Laura, but rapid strengthening is possible.

Tropical Storm Sally will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Sally toward the northwest during the next 48 hours.  On its anticipated track Tropical Storm Sally could approach the Gulf Coast by Monday night or Tuesday.  Sally may move more slowly toward the north when it nears the western end of the high pressure system.  It will almost certainly be a hurricane when it makes landfall.  Sally could cause a storm surge of 10 feet (3 meters).  Since it will be moving slowly, Sally could drop very heavy rain and fresh water flooding will be possible.

Elsewhere, Tropical Storm Paulette continued toward Bermuda, Tropical Depression Rene churned in the Central Atlantic and Tropical Depression Twenty formed over the Eastern Atlantic.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Paulette was located at latitude 28.4°N and longitude 58.5°W which put it about 460 miles (740 km) southeast of Bermuda.  Paulette was moving toward the northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 987 mb.  A Hurricane Warning was in effect for Bermuda.

At 5:00 p.m. EDT on Saturday the center of Tropical Depression Rene was located at latitude 24.3°N and longitude 45.6°W which put it about 1200 miles (1935 km) east-northeast of the Northern Leeward Islands.  Rene was moving toward the northwest at 14 m.p.h. (22km/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 1006 mb.

At 5:00 p.m. EDT on Saturday the center of Tropical Depression Twenty was located at latitude 11.4°N and longitude 33.5°W which put it about 2030 miles (3265 km) east of the Northern Leeward Islands.  The depression was moving toward the west-northwest at 9 m.p.h. (15 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 1005 mb.