September 1, 2012 - Tropical Storm Isaac (09L) over Louisiana

Tropical Storm Isaac (09L) over Louisiana

The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASAís Aqua satellite captured this true-color image of Isaac on August 30 at 1930 UTC (2:30 p.m. CDT) drenching the Gulf Coast states of Louisiana and Mississippi. Although the eye was well inland, near Monroe, Louisiana, the clouds and storm bands measured about 249 miles (400 km) across.

Just before this image was captured, at 1800 UTC (1:00 p.m. CDT), the National Hurricane Center (NHC) reported that Isaac was located about 25 miles (45 km) southwest of Monroe, Louisiana and carried maximum sustained winds of 40 mph (65 km/h), and it was no longer at hurricane strength. Tropical storm force winds extended up to 195 miles (315 km) outward, mainly to the southeast of the center over water and along the coasts of Mississippi and southeastern Louisiana.

Hurricane Isaac reached hurricane strength the morning of August 28 shortly before making a brief landfall near the mouth of the Mississippi River at 2345 UTC (6:45 p.m. CDT). At that time, Isaac qualified as a Category 1 hurricane, carrying one minute sustained winds of about 80 mph (130 km/h). The storm then skirted the southeastern Louisiana coast and made a second landfall west of Port Fourchon at 0712 UTC (2:15 a.m. CDT) on August 29, at about the same intensity. By August 30, Isaac had weakened, but still carried extremely heavy rain throughout the region as it slowly crawled inland. On August 31, the storm had weakened to a Tropical Depression, with maximum sustained winds reported near 25 mph (40 km/h) at 0900 UTC (4:00 a.m. UTC) and was slowly moving northward. Isaac is expected to turn northeast and track over the mid-Mississippi Valley and into the Ohio Valley on Labor Day, Monday, Sept. 3 as it continues to crawl to the Mid-Atlantic.

As a result of the heavy rainfall, flooding has been widespread, with Louisiana the hardest hit state. According to the National Hurricane Center, as of 7:00 p.m. CDT August 30 the city of New Orleans had received 20.08 inches of rain, and Grand Bay, Alabama received 11.07 inches. Kiln, Mississippi had received 17.04 inches and Vero Beach, Florida had received 17.04 inches of rain.

A storm surge of 8.8 feet was reported at Shell Beach, Louisiana, and the US Geological Survey reported that the storm surge drove water up the Mississippi River at a pace nearly 50 percent faster than the downstream flow for at least 24 hours, producing a crest 10 feet above the riverís normal height at Belle Chase, LA. The south-flowing waters of the Mississippi were reported to have turned northward in the face of the surge, making the river flow backwards in the storm-affected region.

Image Facts
Satellite: Aqua
Date Acquired: 8/30/2012
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC