Flash Flood — Micronesia, Guam

2025-08-25 · near Pohnpei, Micronesia, Guam

Event narrative

Video on social media showed flash flooding due to the nearby river (likely the Lehnmesi River) overflowing due to heavy rain and flowing up to a house. This was located in Kitti, one of the twelve administrative divisions of Pohnpei and located in the southwest sector of the island. Caption of video states this is the first time the river flooded up to their house since moving in (length of time unknown). Water is completely covering the low part a one land road/driveway and it is difficult to judge depth. The car port near the road appears to be elevated and water is about 2 inches deep when comparing it to the tires of the 3 vehicles parked in the car port, and while the camera pans around from the car port to a patio area, a cinder block about 6 inches is size is seen competely submerged next to the house. An automated weather station at Weather Service Office (WSO) Pohnpei, located in Kolonia (north part of the island and south of the airport), reported 2 inches of rain falling in 2 hours (1149ChST to 1349ChST) with rain rates ranging 2.83 to 3.78 inches from 1234ChST (1334LST) to 1304ChST (1404LST). Damage reports are limited from Pohnpei, but costs were roughly estimated to be around 5 Thousand $USD for miscellaneous property damage.

Wider weather episode

The Intertropical Convergence Zone (ITCZ) developed across eastern Micronesia, producing areas of gusty winds and heavy rainfall, especially along embedded trade-wind troughs. Heavy rainfall impacted Pohnpei on August 25 with an automated weather station at Weather Service Pohnpei recording rain rates from 2.83 to 3.78 inches from 1234ChST (1334LST) to 1304ChST (1404LST). Then on August 28th, ASCAT wind data showed 30 kt winds along a sharp trough moving near Pohnpei and producing heavy showers and isolated thunderstorm, these wind reached Pohnpei around 1900-2000ChST (2000-2100LST) lead to power outages island wide due to downed trees.

View location on OpenStreetMap → (6.8204, 158.1627)

Source: NOAA Storm Events Database, event_id 1294578. Narrative written by the NWS forecast office that issued the report.