Tropical Storm Dianmu Strengthening

Tropical Depression 05W formed east of the island of Ishigakijima, Japan, then strengthened into Tropical Storm Dianmu. Two instruments on Aqua provided an infrared and microwave look at Dianmu and caught signs that the tropical storm was strengthening on its way toward South Korea. The name Dianmu is the name of the goddess of thunder and lightning in Chinese folklore.

Early on August 8, Dianmu formed in the Northwestern Pacific Ocean and by 2100 UTC (5 p.m. EDT) Dianmu had maximum sustained winds near 35 knots (40 mph) and was about 180 miles southwest of Okinawa, Japan. On August 9 at 04:35 UTC (12:35 a.m. EDT), the Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua satellite captured an infrared image of Tropical Storm Dianmu. The AIRS infrared image showed very cold cloud-top temperatures and showed banding of strong thunderstorms around the north, east and south of the center of circulation.

Those cloud tops were so high that they were colder than -63 Fahrenheit. The center of circulation was also clearly visible in the infrared image and appeared as a small circle. At 1500 UTC (11 a.m. EDT), Dianmu’s maximum sustained winds were near 52 mph (45 knots). It was located about 180 nautical miles northwest of Okinawa, Japan. That’s near 29.2 North and 125.3 East.

Dianmu is moving north at 17 mph and creating 18-foot high waves. Forecasters at the Joint Typhoon Warning Center in Pearl Harbor, Hawaii forecast Dianmu to continue on a northward track in the Northwestern Pacific Ocean. A ridge of high pressure sitting east of Japan is causing the storm to track north and it will continue in that direction for the next day. The Joint Typhoon Warning Center expects Dianmu to intensify because upper level winds will diminish.