System 93W is a large low pressure area in the Western North Pacific Ocean that appears poised for tropical development in NASA satellite imagery. The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA’s Aqua satellite captured both an infrared and visible image of System 93W on May 4 at 01:53 UTC. The width of the AIRS image track is 1056 miles, the width of System 93W appears to be approximately 800 miles from west to east. The AIRS imagery showed an improved low-level circulation center and unorganized, but deep convection. Convection is rapidly rising air that forms the thunderstorms that power a tropical cyclone.

The strongest convection appeared around the center of System 93W’s circulation where cloud-top temperatures were measured to be as cold as or colder than -63F/-52C. Cloud-top temperatures are important because they tell forecasters how high thunderstorms are, and the higher the thunderstorm, the colder the cloud tops and the more powerful the thunderstorms.

The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA’s Aqua satellite passed over System 95B from its orbit in space and captured an infrared image of the low pressure area on April 29 at 07:53 UTC. Infrared imagery acts like taking the temperature of the system’s clouds – and there were some high, very cold clouds that indicated powerful convection and strong thunderstorms in the center. Some cloud top temperatures were as cold as or colder than -63F/-52C. Infrared imagery indicated that there was scattered convection around all sides of the low-level center, and even some curved banding of thunderstorms.

On April 29, System 95B was located about 420 nautical miles east-northeast of Colombo, Sri Lanka near 9.5 North and 96.5 East. System 95B is drifting and currently has estimated sustained surface winds between 15 and 20 knots. Despite the waters in the Bay of Bengal being warm enough to sustain the development of a tropical cyclone, there is a westerly wind field present.