Heavy Rain · American Samoa

A landslide occurred along the main road in Seetaga village, blocking the westbound lane. A University of Hawaii/American Samoa Power Authority rainfall station in Aasu Village (approximately 1'2 miles northeast of the incident site) measured 0.76 inches of rain between 11 AM and Noon, aligning with the reported landslide time. Soils were already saturated from persistent above-average rainfall since October, with 2.18 inches measured at Aasu Village over the broader episode. The combination of saturated grounds and short-duration heavy rainfall likely contributed to the landslide.

A subtropical high pressure system positioned to the southwest of American Samoa and an equatorial ridge to the north enhanced low-level wind convergence with a surface trough over the islands. This synoptic setup produced periods of heavy rainfall across the territory. From November 16th through midday November 17th, WSO Pago Pago measured 1.67 inches of rain. Ongoing wet conditions since October contributed to saturated soils across the islands.