Tropical Storm Ida Prompts Hurricane Watch for Louisiana and Mississippi

The threat posed by Tropical Storm Ida prompted the issuance of a Hurricane Watch for the coast of Louisiana and Mississippi on Thursday night. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Ida was located at latitude 18.6°N and longitude 80.5°W which put it about 65 miles (105 km) southeast of Grand Cayman. Ida was moving toward the northwest at 12 m.p.h. (19 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. (65 km/h). The minimum surface pressure was 1006 mb.

A Hurricane Watch was issued for the portion of the coast from Cameron, Louisiana to the Mississippi/Alabama border. The Hurricane Watch included New Orleans, Lake Ponchartrain and Lake Maurepas. Tropical Storm Warnings were in effect for the Cayman Islands. Tropical Storm Warnings were also in effect for the Cuban provinces of Matanzas, Mayabeque, Havana, Artemisa, Pinar del Rio and the Isle of Youth. A Tropical Storm Watch was in effect for the portion of the coast from the Mississippi/Alabama border to the Alabama/Florida border.

The circulation around Tropical Storm Ida was gradually becoming more organized. A few more thunderstorms were beginning to develop near the center of Ida. A rainband was wrapping around the eastern and northern sides of the center of circulation. However, the distribution of thunderstorms was still asymmetrical. The strongest thunderstorms were occurring in bands forming on the eastern side of Tropical Storm Ida. An upper level low near Florida was producing south-southwesterly winds that were blowing over the western side of Ida’s circulation. Those winds were causing moderate vertical wind shear and they were contributing to the asymmetrical distribution of thunderstorms. Wind to tropical storm force extended out 70 miles (110 km) in the northeastern quadrant of Tropical Storm Ida. The winds in the other parts of Ida’s circulation were blowing at less than tropical storm force.

Tropical Storm Ida will move around the southwestern part of a subtropical high pressure system over the Atlantic Ocean during the next several days. The high will steer Ida toward the northwest. On its anticipated track Tropical Storm Ida will move over the Cayman Islands during the next few hours. Ida could be near western Cuba on Friday evening. Tropical Storm Ida will bring gusty winds and locally heavy rain to the Cayman Islands and parts of western Cuba. Ida will move over the Gulf of Mexico during the weekend. It could approach the central coast of the Gulf of Mexico on Sunday.

Tropical Storm Ida will move into an environment that will become more favorable for intensification during the next 60 hours. The upper low near Florida will move off to the northwest and it will weaken. When the upper low weakens, they vertical wind shear will decrease. Ida will move over water where the Sea Surface Temperatures are near 30°C. Ida is likely to strengthen to a hurricane during the next 36 hours. An upper level ridge will be over the Gulf of Mexico during the weekend. The upper level winds will be weak and there will be little vertical wind shear. Ida could intensify rapidly once an inner core with an eye and an eyewall develop. Ida could rapidly intensify to a major hurricane over the Gulf of Mexico.

On its anticipated track Ida could approach the coast of Louisiana on Sunday. Ida could be a major hurricane when it nears the coast. Ida will bring strong winds and locally heavy rain to the central Gulf Coast. It could generate a significant storm surge of up to 7 to 11 feet (2 to 3.3 meters). A Storm Surge Watch has been issued for the coast from Sabine Pass to the Alabama/Florida border. The Storm Surge Watch includes Vermilion Bay, Lake Borgne, Lake Pontchartrain, Lake Maurepas, and Mobile Bay.