Ketchikan faces 2 to 3.5 inches of rain, road ponding through Monday

Drivers in the Ketchikan area should expect standing water on roads overnight into Monday as an atmospheric river crosses the southern panhandle, with rainfall totals that could reach 2 to 3.5 inches by Monday afternoon, the National Weather Service in Juneau said Sunday.

The heaviest rain is expected after 4 p.m. Sunday through early Monday morning, with rates near 0.3 inches per hour over Ketchikan, Metlakatla and Misty Fjords. Misty Fjords is expected to see the highest totals. Small streams and rivers may rise, but forecasters said no river flooding is expected at this time.

The 3:34 p.m. statement described moderate to high confidence and added the roadway ponding warning. It was still the office's most recent word on the storm Sunday evening. The office's area forecast discussion runs slightly higher, putting 24-hour totals at 2.5 to 3.5 inches, with isolated spots reaching 4 inches.

Mariners face a separate hazard. A Small Craft Advisory runs through Monday morning for Clarence Strait, where the marine forecast calls for southeast wind to 25 knots, "Gusts to 35 kt late. Seas 5 ft building to 8 ft." The advisory itself, updated at 3:48 p.m., runs until 7 a.m. Monday and puts seas at 6 to 8 feet, calling conditions hazardous to small craft. Pilots should expect visibility as low as 2 to 3 miles and ceilings down to 500 to 1,000 feet around Ketchikan, Misty Fjords and Annette Island overnight.

Aaron Jacobs, senior service hydrologist at NWS Juneau, wrote in a 2018 research poster that coastal watersheds here are adapted to near-constant rain, and that significant flooding comes when rainfall "lasts for an unusually long time."

Residents can report flooding to the Weather Service at 1-907-266-5127.