Tropical Storm 03S (Southern Indian Ocean) - NASA's TRMM Satellite Sees Tropical Storm 03S Form in Southern Indian Ocean

 TRMM data on Dec. 6 at 0401 UTC revealed that the heaviest rain (red) in newborn Tropical Storm 03S was occurring around the western side, where there were areas of rain falling at a rate of 2 inches (50 mm) per hour. Credit: NASA/TRMM

The third tropical cyclone of the Southern Indian Ocean season formed today, Dec.6, as NASA's Tropical Rainfall Measuring Mission satellite known as TRMM passed overhead. TRMM captured rainfall rate data from Tropical Storm 03S and noticed some powerful thunderstorms around the center of circulation that hinted it would intensify from a low pressure area into a tropical storm in a short time.

NASA's TRMM satellite passed over Tropical Storm 03S (TS03S) on Dec. 6 at 0401 UTC (Dec. 5 11:01 p.m. EST, U.S.). TRMM data revealed a hot towering thunderstorm higher than 9.3 miles (15 kilometers) around the center of circulation. A "hot tower" is a tall cumulonimbus cloud that reaches at least to the top of the troposphere, the lowest layer of the atmosphere. It extends approximately nine miles (14.5 km) high in the tropics. The hot towers in Bopha were over 9.3 miles (15 km) high. These towers are called "hot" because they rise to such altitude due to the large amount of latent heat. Water vapor releases this latent heat as it condenses into liquid.

NASA research has indicated that the presence of hot towers typically means that the storm will intensify in the next six hours. After the TRMM pass, the low pressure area that was formerly System 98S did intensify into Tropical Storm 03S. TRMM data also revealed that the heaviest rain in the storm was occurring around the western side, where there were areas of rain falling at a rate of 2 inches (50 mm) per hour.

At 1500 UTC (10 a.m. EST, U.S.) on Dec. 6, TS03S had maximum sustained winds near 35 knots (40 mph/64.8 kph). It was located about 385 nautical miles (443 miles/713 km) southeast of Diego Garcia, near 12.4 south latitude and 76.8 east longitude. TS03S was moving to the west at 8 knots (13.5 mph/14.8 kph).

Forecasters at the Joint Typhoon Warning Center expect TS03S to intensify over the next couple of days before it hits adverse atmospheric conditions. TS03S is currently no threat to land.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center