Flood — Ketchikan Channels, Alaska

2014-01-14 · near Ketchikan, Ketchikan Channels, Alaska

Event narrative

It rained thirty seven point twenty three inches over the Ketchikan area for about thirty six days straight with just 4 days less than a trace. A strong weather front moved through the area and produced heavy rain of three point twenty one inches on January 14. The very moist antecedent soil conditions, high rain rates along with strong winds gusts of fifty-eight mph triggered land/mudslides. These slides knocked down power lines and the power to the entire city of Ketchikan for a few hours. A slide on Price of Wales Island damaged a home near the Hollis area with another big slide that blocked the road near the town of Coffman Cove.

Wider weather episode

A strong and very moist weather front with a tropical connection moved across Southeast Alaska January 13 and 14. An anomalous ridge of high pressure set up over the eastern Pacific and western North America during the first week of January. The blocking ridge was oriented in a way that it steered a large plume of high precipitable water values northward. The associated atmospheric river moved into the eastern Gulf of Alaska from the North Pacific and then over the panhandle on January 14. The front produced strong wind gusts over the area as the front moved over the area. The combination of the wind and very wet soil conditions from almost 35 straight days of rain produced mud-slides over Prince of Wales Island, Ketchikan and Sitka areas near steep terrain and/or clear cut areas.

View location on OpenStreetMap → (55.4719, -131.7783)

Source: NOAA Storm Events Database, event_id 489388. Narrative written by the NWS forecast office that issued the report.