Flood — Somerset, Maine

2023-12-18 to 2023-12-21 · near Fairfield, Somerset, Maine

Event narrative

Catastrophic flooding occurred along the Kennebec River at Skowhegan following heavy rain and snowmelt event on the 18th. Heavy rain averaging 5 inches fell across the entire Kennebec Valley, and in the mountains an additional 3 inches of snowmelt runoff resulted in major flooding for the Kennebec River and its headwater tributaries. In Madison, the flood exceeded the record event in 1987, however in Skowhegan the flood levels were a few feet lower. The streamflows were estimated around 178 kcfs which falls between a 100 and 500 year flood, otherwise referred to as a 1% and 0.2% annual chance exceedance event. The majority of the property flooding occurred on the east side of the river along Route 201, however homes along Winding Hill Road in Norridgewock also sustained significant flood damage. In Skowhegan, Island Avenue was inundated up to 8 inches deep on the entrance to the southern bridge from route 201. Water depths were up to 5 feet on Route 2 just south of the island. Over a dozen properties, both residential and business were damaged in Skowhegan alone. The estimates in losses are over $10 million for public and private.

Wider weather episode

Low pressure began organizing in the Gulf of Mexico on the 16th, setting record low sea level pressures as it traversed the Southeast through the 17th. Strong high pressure over the North Atlantic created a deep southeasterly flow that drew warm air into New England ahead of the approaching storm. By the time precipitation arrived on the evening of the 17th, temperatures were warm enough for rain everywhere except the highest peaks. Early on the 18th a shortwave trough was approaching from the Great Lakes and led to rapid deepening of the low pressure as it paralleled the Eastern Seaboard. Even as the center of the storm remained near Chesapeake Bay on the morning of the 18th, a strong low level jet had developed and winds began to gust in excess of 50 mph well inland from the coast. Damaging wind gusts continued into the afternoon. Hundreds of thousands of customers lost power due to falling limbs and downed wires. The anomalously warm air mass also led to intense rainfall rates beginning on the evening of the 17th, which continued into the 18th. Upsloping winds also enhanced precipitation along the southeast facing slopes of the mountains. Widespread 3 to 4 inches of rain fell, with isolated pockets of 6 to 8 inches. This fell on top of snow that was ripe from previous rainfall about a week earlier. An additional 2 to 3 inches of snow water equivalent was likely added to rainfall runoff. Numerous road washouts and road closures occurred due to flash flooding and fast responding small stream and tributaries. Widespread moderate to major flooding occurred along mainstem rivers. The storm destroyed 13 homes, caused major damage to 106 others, with an additional 65 homes receiving minor flood damage. Private damage was in the millions with public infrastructure damage of 20+ million being reported by FEMA.

View location on OpenStreetMap → (44.5874, -69.5434)

Source: NOAA Storm Events Database, event_id 1151026. Narrative written by the NWS forecast office that issued the report.