The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite captured an infrared image of the tropical low pressure area called "System 97W" on April 6 at 0611 UTC (2:11 a.m. EDT). Infrared data basically takes the temperature of atmospheric, land or oceanic objects. The infrared data revealed the coldest temperatures were in thunderstorm cloud tops around the center of System 97W's circulation. Those cloud tops were as cold as or colder than -63 degrees Fahrenheit (-52 Celsius) indicating strong convection (rapidly rising air that forms the thunderstorms that power a tropical cyclone). That's an indication that the storm is getting stronger. There is also a banding of thunderstorms around the low-level center of circulation.
AIRS data also showed that the sea surface temperatures were above 80F (26.7 C), which is the threshold for maintaining a tropical cyclone, so the water remains a power source for intensification. At 0600 UTC on April 6, 2011, System 97W was about 170 miles west-northwest of Brunei near 6.2 North and 112.4 East. Maximum sustained surface winds are estimated at 15 to 20 knots. Minimum sea level pressure is estimated to be near 1008 millibars.