Hurricane Ida Rapidly Intensifies to Cat. 4

Hurricane Ida rapidly intensified to Category 4 on the Saffir-Simpson Scale during the overnight hours. At 7:00 a.m. EDT on Sunday the center of Hurricane Ida was located at latitude 28.3°N and longitude 89.4°W which put it about 75 miles (120 km) south-southeast of Grand Isle, Louisiana. Ida was moving toward the northwest at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 175 m.p.h. (280 km/h). The minimum surface pressure was 935 mb.

A Hurricane Warning was in effect for the portion of the coast from Intracoastal City, Louisiana to the Mouth of the Pearl River. The Hurricane Warning included New Orleans, Lake Pontchartrain and Lake Maurepas. Tropical Storm Warnings were in effect for the portions of the coast from Cameron, Louisiana to Intracoastal City and from the Mouth of the Pearl River to the Alabama/Florida Line.

Hurricane Ida rapidly intensified to Category 4 southeast of Louisiana on Saturday night. A circular eye with a diameter of 17 miles (28 km) was at the center of Ida. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Hurricane Ida. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the hurricane. The removal of mass caused the surface pressure to decrease rapidly and the wind speed increased quickly.

The circulation around Hurricane Ida increased in size when it rapidly intensified. Winds to hurricane force extended out 40 miles (65 km) from the center of Ida. Winds to tropical storm force extended out 140 miles (220 km) from the center of circulation. The Hurricane Intensity Index (HII) for Ida was 31.5. The Hurricane Size Index (HSI) was 14.1 and the Hurricane Wind Intensity Size Index (HWISI) was 45.6. Hurricane Ida was as strong as Hurricane Laura was last year and Ida was just a little smaller than Laura was. Hurricane Ida will be capable of causing regional severe damage.

Hurricane Ida will move through an environment favorable for intensification during the next few hours. Hurricane Ida will move over water where the Sea Surface Temperature is near 30˚C.  It will be under an upper level ridge over the Gulf of Mexico.  The winds will be weak in the ridge and there will be little vertical wind shear.  Ida could strengthen a little more before it makes landfall in southeast Louisiana. Hurricane Ida could pull some slightly drier air over the southeastern U.S. into its circulation when it nears the coast. If that happens, Ida will stop intensifying and it could weaken slightly just before it makes landfall.

Hurricane Ida will move around the southwestern part of a high pressure system that extends from the Atlantic Ocean to the eastern Gulf of Mexico.  The high will steer Ida toward the northwest during the next 12 hours.  On its anticipated track Hurricane Ida is likely to make landfall the coast of southeast Louisiana as a major hurricane in a few hours.  Ida will be capable of causing severe damage. Hurricane Ida could cause a storm surge of up to 12 to 16 feet (3.6 to 5 meters). A Storm Surge Warning has been issued for the coast from west of Vermillion Bay to the Mississippi/Alabama border. The Storm Surge Warning includes Vermillion Bay, Lake Borgne, Lake Pontchartrain, and Lake Maurepas. Hurricane Ida move toward the north as it moves inland over southeastern Louisiana. Ida could produce hurricane force winds in New Orleans and Baton Rouge. Widespread power outages could occur in southeast Louisiana. Ida will also drop heavy rain over parts of eastern Louisiana and Mississippi. Flash floods could occur in that region.