Flood — Yakutat Coastal, Alaska

2014-01-23 to 2014-01-24 · near Yakutat, Yakutat Coastal, Alaska

Event narrative

The persistent onshore flow with numerous weather systems moving over the Yakutat area from mid December through the end of January produced thirty-four point forty-five inches in forty-four days with only two days of no rain. It was the 5th wettest forty-four day period on record for that time period with an daily average rainfall amount greater than three quarters of an inch. January was also the 4th wettest on record with three daily records on the, 5th(three point sixty one), 22nd(three point thirty six) and the 23rd(three point ninety five). Minor to moderate flooding was reported across the Yakutat area on the 23rd and 24th after seven point thirty one inches of rain fell at the airport and nine point ninety six inches fell at the Situk River gauge in just under 2 days. The combination of record rainfall amounts and very moist antecedent soil conditions produced a lot of runoff into streams and drainage ditches. The massive amount of runoff caused the Situk River to crest at seventy-two point seventy one feet which is the second highest crest in the 26 year record. The camp ground, trail and boat launch near the nine mile bridge along the Situk River flooded significantly. Forest Highway #10 going out to the upper Situk River and to the Harlequin Lake was flooded in certain areas with some spots along the road totally washed out. There was also flooding that took place along the lower portions of the Situk River with portions of the established trail system destroyed. The road going out to the lower Situk River landing near mile marker 4.2 was flooded and the road going out to Canon Beach was flooded with about a foot of water. The road going out to Tawa Creek and Lost River was also flooded.

Wider weather episode

A persistent anomalous high amplitude upper level ridge over the eastern Pacific and western North America started to build to the north and cutoff over Southeast Alaska in mid January. The series of atmospheric rivers that affected Southeast Alaska from the mid December through the end of January shifted to the west by the third week. This shift refocused the stream of moisture from the tropics to the west and was pointed right at the Northern Gulf of Alaska coast. This atmospheric river was evident from satellite imagery. When the warm front moved over the Yakutat area in the morning hours of the 23rd the weather sounding recorded the highest ever precipitable water value for that time of year, one point zero seven inches. There was about 36 hours of moderate to heavy precipitation as the front was slow to move across the area. The large amount of rain during that time period produced minor to moderate flooding over the Yakutat area.

View location on OpenStreetMap → (59.6158, -139.5538)

Source: NOAA Storm Events Database, event_id 493055. Narrative written by the NWS forecast office that issued the report.