A Hurricane Watch was issued for a portion of the northern Gulf Coast on Wednesday because of the threat posed by Tropical Storm Isaias.  At 2:00 p.m. EDT on Wednesday the center of Tropical Storm Isaias was located at latitude 22.6°N and longitude 93.4°W which put the center about 520 miles (840 km) south-southwest of the Mouth of the Mississippi River.  Isaias was moving toward the east-northeast at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 997 mb.

A Hurricane Watch is in effect for the portion of the coast from Bay St. Louis, Mississippi to Indian Pass, Florida.

A Tropical Storm Watch is in effect for the portion of the coast from the Jefferson Parish/Plaquemines Parish line in Louisiana to Bay St. Louis, Mississippi.

A Tropical Storm Watch is in effect for the portion of the coast from Indian Pass to Aucilla River, Florida.

Tropical Storm Isaias was strengthening on Wednesday afternoon.

New thunderstorms continued to develop near the center of Tropical Storm Isaias.  Thunderstorms were also occurring in bands that were revolving around the center of Isaias’ circulation.  Storms near the center of Isaias generated more upper level divergence that pumped more mass away from the tropical storm.  The removal of more mass caused the surface pressure to decrease.

The distribution of wind speeds in Tropical Storm Isaias was becoming more symmetrical.  Winds to tropical storm force extended out 45 miles (75 km) from the center of Isaias’ circulation.

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

An upper level trough over the eastern U.S. and the Gulf of Mexico will steer Tropical Storm Isaias toward the east-northeast during the next 24 hours.  A different upper level trough approaching from the Southern Plains west will start to steer Isaias toward the north on Thursday.  Tropical Storm Isaias could reach the northern Gulf Coast by Friday night.

Tropical Storm Isaias is likely to be a hurricane when it reaches the northern Gulf Coast.  Isaias could be a major hurricane when it reaches the coast.  Isaias will bring strong winds and locally heavy rain to the northern Gulf Coast.  Heavy rain could cause flash floods in some locations.

Tropical Storm Isaias could cause a storm surge of up to 12 feet (3.6 meters) along portions of the northern Gulf Coast.

A Storm Surge Watch is in effect for the portion of the coast from the Mouth of the Mississippi River to Yankeetown, Florida.