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Hurricane Season 2011: Tropical Cyclone Grant (Southern Indian Ocean)
MODIS captured a visible image of Tropical Cyclone Grant's remnants on Dec. 27 at 0423 UTC › View larger image
The MODIS instrument aboard NASA's Aqua satellite captured a visible image of Tropical Cyclone Grant's remnants on Dec. 27 at 0423 UTC (Dec. 26, 11:23 p.m. EST). In the image Grant appeared elongated, an indication of weakening.
Credit: NRL/NASA
NASA Satellite Sees Cyclone Grant Weaken and Elongate Over Land

Over the weekend, Tropical Storm Grant has been moving inland over the Northern Territory. NASA satellite data revealed that Grant's cloud cover has elongated and the storm has weakened.

Grant was formerly known as System 94S. On Dec. 25, the low strengthened and the low-level center of circulation consolidated enough to be classified as a tropical storm, and the Joint Typhoon Warning Center named it "Grant." Grant reached tropical storm-force and by Dec. 27, Grant had been downgraded to a tropical low pressure system. It made landfall 186 miles (300 km) east of Darwin on the morning of Dec. 27 (local time, Australia). Heavy rainfall and flooding are the biggest threats from Grant's remnants as the system continues to track over land.

According to the Australian Broadcasting Corporation, Grant moved over the Cobourg Peninsula with wind gusts up to 87 mph (140 kmh). Downed trees and power outages were reported on Croker Island, located 142 miles (230 kilometers) northeast of Darwin. Floodwaters were responsible for the derailing of a freight train between Katherine and Pine Creek. Katherine is a town located 200 miles (320 km) southeast of Darwin in the "Top End" of Australia in the Northern Territory.

At 0000 UTC on Dec. 27 (7 p.m. Dec. 26), Grant's remnants had maximum sustained winds near 25 knots (29 mph/46 kmh). It was located 155 nautical miles southeast of Darwin and was moving to the southeast near 4 knots (5 mph/7 kmh) and is expected to turn to the east.

NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Aqua satellite captured a visible image on Dec. 27 at 0423 UTC (Dec. 26, 11:23 p.m. EST). The image showed Grant appeared elongated. Infrared satellite instrument data "showed that Grant had become shallow and disorganized" over the 12 hours before, according to the Joint Typhoon Warning Center.

The Australian Bureau of Meteorology has forecast heavy rainfall from Grant. That rainfall is expected to cause flooding of low lying areas over the Arnhem and northern Roper-McArthur Districts. Higher than normal tide levels between Milingimbi and Groote Eylandt in the Gulf of Carpentaria are expected over the next couple of days

Grant is forecast to continue weakening today. It is expected to move eastward toward the Gulf of Carpentaria late on Dec. 28 (local time). The Joint Typhoon Warning Center noted that once Grant's remnants reach the Gulf, redevelopment is possible.

Text credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.