Coastal Flood — Coastal Rockingham, New Hampshire

2024-03-10 · Coastal Rockingham, New Hampshire

Event narrative

In the Portsmouth region at the Seavey Island gauge, the tide reached 11.97 feet MLLW at 10:47AM. The storm surge was recorded at 2.07 feet. In Hampton, New Hampshire, Highland Ave along NH101 flooded due to high water levels and battering surf. Most closures were due to inundation coastal flooding, but wave action flooding along the exposed coastline also caused road closures due to debris and over wash. NH 1A was closed from NH286 to NH111 due to flooding. Further up the coast in Portsmouth, NH 1B causeway was flooded and closed at high tide. Waterfront parking lots were also closed in the Portsmouth Area due to high waters at high tide.

Wider weather episode

High pressure in control on the 9th began to slide northeast through the day as primary low pressure moved through the Great Lakes into southern Canada. A secondary area of low pressure developed over inland areas of the Carolinas. Sustained warm air advection forced a large area of moderate to heavy precipitation up and over the colder near-surface air mass. Light precipitation began as a mix, but in the higher elevations quickly changed to snow, heavy at times. Closer to the ocean, the coastal front progressed inland and snow changed to rain, which also fell heavy at times overnight. Warm air eventually won out, with precipitation ending as a light rain or mix and significant settling of existing snowpack. Strong onshore flow interacted with a high astronomical tide to bring coastal flooding to the Seacoast of New Hampshire.

Source: NOAA Storm Events Database, event_id 1169876. Narrative written by the NWS forecast office that issued the report.