Tropical Depression — Saipan, Guam

2024-09-11 · Saipan, Guam

Event narrative

Saipan and Tinian reported no wind-related damage with the passage of Tropical Storm Bebinca. Near Saipan's airport (215 ft in elevation), max sustained wind of 31 kt (36 mph) was recorded around 0315ChST with a max gust of 38 kt (44 mph) around the same time. Only higher elevations saw winds around tropical storm strength with a private weather station on Wireless Ridge (elevation of 673 ft) reporting max sustained winds of 39 kt (45 mph) at 0325ChST and a max gust of 46 kt (53 mph) at 0655ChST. On Saipan, there were problems with runoff due to heavy showers, resulting in considerable erosion of gravel roads. Much of the highway/street infrastructure along western Saipan is under construction, with exposed gravel and dirt in many areas from San Antonio northward to Garapan. Problems were compounded in the days of monsoon surge later in the week, and more so on Monday, September 16 with a strong monsoon surge. Winds with the second surge exceeded those during Tropical Storm Bebinca, with more impacts on the 16th than the 10-11th. See High Wind entry for monsoon surge on September 16th.

Wider weather episode

TS Bebinca originated in the Federated States of Micronesia near Pohnpei and Kosrae as a surface trough. Bebinca gradually consolidated into a closed low-level circulation as it moved WNW past Pohnpei and Chuuk as was monitored as Invest 95W. The Joint Typhoon Warning Center (JTWC) issued its first warning on TD 14W as it sat about 200 miles SE of Guam on 10 Sep. It was briefly elevated to a 40 mph TS as it passed to the west of southern Guam early morning on the 11th. Rainfall was the more notable hazard with Guam seeing the bulk of rainfall. Heavy rains were less prevalent across the CNMI, but Saipan did see some erosion and runoff due to all the loose soil and gravel from large stretches of road work. Little wind damage was reported beyond some downed limbs and fleshier vegetations such as banana and papaya trees.

Source: NOAA Storm Events Database, event_id 1219148. Narrative written by the NWS forecast office that issued the report.