Flood · American Samoa

An NWS employee reported a landslide in Leone Village during the morning of November 20th. Dirt and debris blocked both ends of the main roadway through the village. A nearby University of Hawaii/American Samoa Power Authority rainfall gauge located in Aasu Village, approximately one mile north of the landslide site, recorded 1.71 inches of rainfall between 3:00 AM and 10:00 AM. This short-duration heavy rainfall, combined with already saturated soils following multiple weeks of above-average rain, likely contributed to the resulting landslide.

A strong trough produced slow-moving thunderstorms across American Samoa from the overnight hours of November 19th through midday November 20th. Weak steering flow supported repeated cell development over the same areas, resulting in enhanced rainfall. These storms generated localized heavy rainfall, with WSO Pago Pago measuring 2.85 inches in 36 hours. Soils were already saturated from persistent above-average rainfall throughout October and November. The combination of renewed heavy rainfall and saturated antecedent conditions led to flooding impacts across the territory and contributed to a landslide on Tutuila Island.