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Hurricane Season 2008: Asma (Indian Ocean)
Oct. 23, 2008

Southern Hemisphere's Tropical Storm Asma Now a Memory

Satellite image of Asma Credit: NASA/JPL/Colorado State University/Naval Research Laboratory-Monterey
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Tropical Cyclone Asma formed on October 19, and by October 23, the first tropical cyclone of the Southern Hemisphere was a remnant low pressure area.

On October 19, NASA's CloudSat satellite flew overhead in space and captured this image of Asma in the southern Pacific Ocean. At that time Asma's winds were approximately 30 knots (34 mph) with gusts to 40 knots (46 mph).

NASA's CloudSat Satellite Sliced Asma Sideways

NASA's CloudSat satellite's Cloud Profiling Radar captured a sideways look across Asma. Here, it is compared with a top-down satellite image to show where CloudSat took its sideways view.

The top image is from the MTSAT satellite on Oct. 19, 18:00 Zulu Time (2:00 p.m. EDT). The image was supplied through the U.S. Naval Research Laboratory. The Multi-functional Transport Satellite (MTSAT) series fulfills a meteorological function for the Japan Meteorological Agency and an aviation control function for the Civil Aviation Bureau of the Ministry of Land, Infrastructure and Transport.

The image on the bottom is from NASA's CloudSat satellite also taken on Oct. 19. The red line through the MTSAT satellite image shows the vertical cross section of radar, basically what Asma's clouds looked like sideways. The colors indicate the intensity of the reflected radar energy. The top of Asma's clouds were almost 14 kilometers (9 miles) high.

The blue areas along the top of the clouds indicate cloud ice. Where the solid line (the ground or sea surface) along the bottom of the panel disappears is an area of heavy precipitation. It is likely that in the area the precipitation rate exceeds 30mm/hr (1.18 inches/hour) based on previous studies.

As of October 23 Asma's clouds were scattered and the tropical storm of the Southern Hemisphere was only a memory.

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

Oct. 21, 2008

Asma Gasping For Life

Tropical Cyclone Asma is looking at a very short life in the Southern Hemisphere.

According to the Joint Typhoon Warning Center, the agency that forecasts tropical cyclones in the Indian and western Pacific Oceans, Asma has been weakening from Oct. 20 through Oct. 21.

Tropical Cyclone Asma still had sustained winds near 35 knots (42 mph) but was quickly weakening over an area of cooler waters and increased wind shear (winds that tear a storm apart). On Oct. 21 at 6:00 Zulu Time (2:00 a.m. EDT), Asma was near 12.2 degrees south and 58.8 degrees east. That's about 575 nautical miles north-northeast of la Reunion. Asma tracked westward at 10 knots (11 mph). Asma is expected to continue tracking westward while weakening further. It is expected to dissipate by late in the day on Oct. 22. Text credit: Rob Gutro/Goddard Space Flight Center

Oct. 20, 2008

Tropical Cyclone Asma Forms in the Southern Indian Ocean

Satellite image of Asma Credit: JTWC/SATOPS
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Tropical Cyclone 01s has formed in the Indian Ocean. "01s" means the first storm of the tropical cyclone season in the southern hemisphere. On October 20, 01s strengthened into a tropical storm and was given the name "Asma." Asma means "prestige" in Arabic.

On Oct. 20 at 6:00 Zulu Time (2:00 a.m. EDT), Asma was located near 12.5 degrees south latitude and 61.7 degrees east longitude. That's east of the northern tip of the island nation, Madagascar. Asma had sustained winds near 55 knots (63 mph) and was moving toward the south-southwest near 8 knots (9 mph).

The cyclone has intensified over the past 12 hours after moving into a region of decreasing vertical wind shear (winds that can weaken a storm and tear it apart). Alma is expected to track generally westward over the next 48 hours, and moderate vertical wind shear and passage across cooler water will likely limit this intensification to a slow rate. Current forecast models take the storm toward the northern tip of Madagascar.

The satellite image is from the MTSAT satellite and was supplied through the Joint Typhoon Warning Center.

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