Flash Flood — Merrimack, New Hampshire

2025-06-06 · near West Henniker, Merrimack, New Hampshire

Event narrative

In Henniker, highway and road management reported road damage from flooding along Bear Hill Road, Ray Road, Hemlock Corner Loop and parts of Dodge Hill Road due to heavy downpours dropping around 3 inches of rain on saturated soils.

Wider weather episode

A stationary front stalled over southern New Hampshire on the evening of June 6 into midday on June 7th. Repeated rounds of heavy rain and thunderstorms brought up to 4 inches of rainfall to areas across Merrimack and Hillsborough Counties between 3 and 7 PM. The heavy rain with rates measured over 2 inches per hour at times, was sufficient to cause flash flooding with multiple roads flooded, some with washouts, and some property damage. Numerous severe thunderstorms also developed on the afternoon of June 6th as amble instability and moisture interacted with the stalled front boundary. Large hail and damaging winds were reported.

View location on OpenStreetMap → (43.1443, -71.8503)

Source: NOAA Storm Events Database, event_id 1252490. Narrative written by the NWS forecast office that issued the report.