Tropical Storm — Northern Marianas, Guam

2000-09-05 to 2000-09-08 · Northern Marianas, Guam

Event narrative

In Tinian some banana trees were reported damaged by gusty winds.

Wider weather episode

Tropical Storm Saomai passes close to the Mariana Islands. Saomai developed in the monsoon trough east of Guam on September 1. It developed quickly and became a tropical storm on the 2nd and a typhoon on the 4th. Increased vertical wind shear weakened Saomai to tropical storm strength on the 5th. The storm was heading west and it appeared that it would move north of Tinian. The tropical storm then became captured in the larger circulation of a monsoon gyre that had formed over the region. Rather than continue to move west the tropical storm moved south to just east of Guam on the 6th. It then made a loop and started to move northwestward and passed close to Tinian and Saipan. As it was moving away from the Marianas Saomai increased strength and became a typhoon. Even though Saomai did not make landfall on any island in Marianas, rain bands associated with the tropical storm moved over the area. Rainfall amounts across the Mariana Islands depending on which area of the island remained under rainbands the longest. Greatest 24 hour rainfall totals: 3.95 inches of rain fell at the National Weather Service Office in Tiyan. (midnight on the 6th to midnight on the 7th) Automated observing on Guam from 1000 local on the 6th to 1000 on the 7th: Apra Harbor station observed 7.84 inches Mangilao observed 6.41 inches. Merizo observed 3.11 inches. Fisher and Porter rain gages on Guam observed high amounts From 0600 on the 6th to 0600 on the 7th the Inarajan gage measured 7.60 inches From 0500 on the 6th to 0500 on the 7th the Fena Lake gage showed 8.80 inches and Piti gage showed 9.90 inches. In Saipan 2.42 inches of rain were recorded between 2200 on the 6th to 2200 on the 7th. Wind reports:GuamAt the National Weather Service Office in Tiyan the highest observed wind gust was 39mph at 0122 on the 6th. The highest sustained wind was 25 mph observed at 0854 on the 6th. The Navy COMNAVMAR the highest observed wind gust was 66 mph at 0231 on the7th. The highest sustained wind was 45 mph observed at 0215 on the 6th.Saipan At the International Airport the highest observed wind gust was 41mph at 1419 on the 7th.The highest sustained wind was 33 mph observed at 1411 on the 7th. Both of these observations are the last of several occurrences. Rota At the Airport the highest observed wind gust was 35mph at 0650 on the 7th. The highest sustained wind was 23 mph at 1153 on the 7th. Tinian At the Airport the highest observed wind gust was 29mph at 0850 on the 7th. The highest sustained wind was 21 mph at 1650 on the 7th. Damage reported from SaomaiOn Guam power was knocked out briefly in isolated areas. Gusty winds downed two old wooden telephone poles along Route 17 in Windward Hills. Localized minor flooding in poor drainage areas. Major flooding occurred in Merizo where a poorly designed storm drain clogged up with debris. This resulted in flooding of six houses. At the International Airport two flights were delayed and one cancelled due to the storm. In Saipan there were isolated power outages and minor flooding in poor drainage areas. In Tinian some banana trees were reported damaged.

Source: NOAA Storm Events Database, event_id 5173995. Narrative written by the NWS forecast office that issued the report.