Tropical Storm — Belau, Guam

2004-06-13 to 2004-06-15 · Belau, Guam

Wider weather episode

TROPICAL STORM DIANMUAfter developing about 125 miles southwest of Yap on the morning of June 13th, Tropical Depression 09W moved slowly northwest between Yap and Palau that evening. It became a tropical storm early on the 14th, and appeared to be headed safely away from Yap. However, Tropical Storm Dianmu slowed abruptly and turned to an east-northeast track. Dianmu dealt Yap a glancing blow, passing about 75 miles northwest of that island as a 65 mph tropical storm at about 0400 SST on the 15th. Meanwhile, southwest monsoon flow into Dianmu brought gusty winds and heavy rain to Palau on the 13th and 14th. By 1300 SST on the 15th, Dianmu was a typhoon, centered over 150 miles north of Yap and moving quickly away.At Yap, the highest 2-minute wind was 32 mph; from the south-southwest on the 14th at 2353 SST, and from the west-southwest on the 15th at 0650 SST. The maximum gust of 59 mph from the south-southwest was recorded at 2253 SST on the 14th. Since Yap spent most of its time in a dry slot between Dianmu's central cloud mass and its outer rain band, the greatest 24-hour rainfall at the airport was only 0.56 inches through 1600 SST on the 15th. The lowest sea-level pressure at the airport was 998.3 mb at 0457 SST on the 15th. No damage or injuries were reported at Yap.While Palau had less wind than Yap, much more rain fell there as a result of persistent monsoon flow into Dianmu. The maximum 24-hour rainfall was 5.22 inches through 1300 SST on the 14th, while 7.19 inches fell in the 48 hours ending at 0400 SST on the 15th, resulting in minor flooding. The highest 2-minute wind was only 21 mph on the 14th, while the peak gusts of 44 mph were recorded at the Weather Service Office on the 15th at 0902 SST and 1659 SST. No damage or injuries were reported.

Source: NOAA Storm Events Database, event_id 5432032. Narrative written by the NWS forecast office that issued the report.