When NASA's Aqua satellite flew over Tropical Cyclone Dianne on Feb. 18 at 06:47 UTC (2:47 p.m. Australia/Perth local time/1:47 a.m. EST) it provided information to forecasters that showed Dianne moving farther west than previously forecast. That movement is keeping the storm farther away from Western Australia and that's good news because Dianne strengthened.
The Atmospheric Infrared Sounder (AIRS) instrument on the Aqua satellite showed a larger area of strong thunderstorms around Dianne's center today, Feb. 18, compared to yesterday. The greatest area of deep convection (rapidly rising air that forms the thunderstorms that power the tropical cyclone) are over the northern semi-circle of the storm.
AIRS infrared data takes temperatures of cloud tops and sea surface temperatures and noticed the stark contrast between the two indicating that the thunderstorm cloud tops were very high, very cold (-52C/-63F) and very strong. Meanwhile, the sea surface temperatures were very warm (warmer than 80F/26.5C) and adding power to Dianne.