NASA sees Tropical Storm Alenga intensifying

The Tropical Rainfall Measuring Mission satellite called TRMM again passed over intensifying tropical storm Alenga in the South Indian Ocean on December 5, 2011 at 2103 UTC (6:03 p.m. EST). As expected, Alenga had become better organized with TRMM's Precipitation Radar (PR) seeing scattered bands of heavy rainfall spiraling into the center of the storm.

A 3-D image using TRMM PR was created at NASA's Goddard Space Flight Center in Greenbelt, Md. Very powerful storms were seen in the 3-D image. Some of those powerful thunderstorms reached heights of about 16 km (~9.9 miles). TRMM PR also found a reflectivity value of 53.67 dBZ which is an another indication that very heavy rainfall was occurring in those storms.

On Dec. 7, 2011 at 0600 UTC (1 a.m. EST), Tropical Storm Alenga's maximum sustained winds were up to 55 knots (63 mph/102 kmh)from 45 knots (52 mph/83 kmh)a day ago. Alenga was still safely at sea and far from land. The center of Alenga was located about 415 nautical miles west-southwest of the Cocos Islands near 14.5 South latitude and 90.2 East longitude. Alenga was moving to the east-southeast near 15 knots (17 mph/28 kmh).

On Dec. 7, satellite imagery showed improved banding of thunderstorms around the low-level center of the cyclone. The strongest bands of thunderstorms were on the northern side of Alenga's center.

Tropical Storm Alenga is forecast to keep strengthening because of warm sea surface temperatures and low wind shear. Alenga may reach hurricane-force over the next day or two before encountering strong westerly wind shear and weakening.

Provided by NASA's Goddard Space Flight Center