A broad area of low pressure across the Great Lakes region stalled out well to the west of the region early on Sunday April 30th.  A secondary area of low pressure developed and moved up the Eastern Seaboard and tracked across interior New England from Sunday April 30th through Monday May 1st. Heavy rainfall occurred, and flooding was enhanced for this weather event due to the seasonal timing of the rains with spring soils being high in moisture and the vegetation still dormant.  These two factors lead to increased run-off. Rain started across southern and coastal areas early on Sunday April 30th, with the heaviest rainfall Sunday night into early Monday morning. The rainfall on Sunday produced limited flooding, but set the stage for what was to come by swelling rivers and filling ditches ahead of the heavier rain. Heavy rain started around 3 AM and continued through 10 AM Monday with rainfall rates between 1 to 1.5 inches an hour. This caused flooding to rapidly develop, resulting in widespread flash flooding. The rainfall ended by midday on Monday May 1st. Runoff spilled into tributary rivers and major rivers that led to ongoing flooding for the next several days with most rivers cresting late on Monday May 1st or on May 2nd.

Flood in CARROLL, NEW HAMPSHIRE
From 01-MAY-23 06:00:00 to 02-MAY-23 01:00:00 (EST-5)
Location: CONWAY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

The Saco River came out of banks on May 1st that caused significant flooding to several camps and campgrounds between Conway and Bartlett.  The flooding significantly impacted travel in and out of the area due to closed roads. Flooding started on the upper portion of the West Side Road with minor property inundation. The floodwater moved downstream causing significant damage to area campgrounds in North Conway and backwater on the Ellis River.  In North Conway a section of West Side Road flooded, cutting off access to several homes. River Road flooded on the west bank of the Saco River flooding agricultural lands.  Floodwaters inundated first floors of properties in Transvale Acres.  Moat Brook Road flooded cutting off seasonal camps. Widespread agricultural flooding occurred between Conway and Fryberg.  The river levels were at the bridge deck of the Saco River Covered Bridge in Conway.  The USGS river gage in Conway crested at a 13.6 feet, exceeding the 9 foot flood stage by 4.6 feet.

Flash Flood in GRAFTON, NEW HAMPSHIRE
From 01-MAY-23 06:00:00 to 01-MAY-23 08:00:00 (EST-5)
Location: LINCOLN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Rainfall between 0.5 and 1.25 inches fell over still frozen soils in portions of the White Mountains during the morning of May 1. The excessive runoff resulted in significant and multiple washouts on the Kancamangus Highway in Lincoln, which lies between the steep slopes of mountains peaking over 3,000 feet.

Flash Flood in GRAFTON, NEW HAMPSHIRE
From 01-MAY-23 06:00:00 to 01-MAY-23 08:00:00 (EST-5)
Location: BETHLEHEM JCT
Flood cause: Heavy Rain / Snow Melt
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Rainfall between 0.5 and 1.25 inches fell over still frozen soils in portions of the White Mountains during the morning of May 1. The excessive runoff resulted in significant and multiple washouts on the Mount Washington Auto-road in the White Mountains.

Flash Flood in CARROLL, NEW HAMPSHIRE
From 01-MAY-23 05:44:00 to 01-MAY-23 08:15:00 (EST-5)
Location: TAMWORTH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Locally heavy rain caused New Hampshire Route 113 to close due to flooding in multiple areas between Tamworth and Madison. Route 153 was closed due to flooding in Eaton.

Flood in CARROLL, NEW HAMPSHIRE
From 01-MAY-23 09:19:00 to 01-MAY-23 13:00:00 (EST-5)
Location: CENTER OSSIPEE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Locally heavy rain caused Route 16B flooding at the intersection of Route 16 in Center Ossipee.