Tropical storm Choi-wan was spinning over open waters of the Northwestern Pacific Ocean when NASA's Aqua satellite saw the strengthening storm.
At NASA's Jet Propulsion Laboratory in Pasadena, California a false-colored infrared image was created using data from the AIRS instrument that flies aboard NASA's Aqua satellite. The AIS image showed the powerful, heavy rainmaking storms with cold cloud tops as cod as -63F/-53C in a comma shaped Typhoon Choi-Wan on Oct. 5 at 2:35 UTC (Oct. 4 at 10:35 p.m. EDT). Strong thunderstorms wrapped from east to south, west and north. The northeastern quadrant of the storm had very little strong thunderstorms, giving the storm the appearance of a tipped over letter "c."
At 1500 UTC (11 a.m. EDT) it was centered near 22.6 North latitude and 152.2 East longitude. That's about 669 nautical miles (769 miles/1,239 km) northeast of Andersen Air Force Base, Guam. Choi-Wan was moving to the west-northwest at 12 knots (13.8 mph/22.2 kph). Maximum sustained winds were near 60 knots (69 mph/111 kph).
The Joint Typhoon Warning Center said that "satellite imagery shows a deepening in the curved banding (or strengthening of thunderstorms developing) along the southern periphery and wrapping into the low level circulation center."
Choi-wan is forecast to move west, later northwest and strengthen into a typhoon before turning north.