Flood — Taiya Inlet, Alaska

2019-09-20 to 2019-09-21 · near Skagway, Taiya Inlet, Alaska

Event narrative

There was a rain event to prime soils a day before the flooding event after a very dry period for the northern inner channels of Southeast Alaska. Moderate to heavy rains moved over the area on September 20th. The high rain rates continued for the next forty-eight hours. Rainfall totals from this time frame ranged from one to two inches near sea level with higher amounts in the headwaters at higher elevations. The very warm temperatures created very high freezing levels that increase runoff from snow or ice melt. The Taiya River started to rise through the afternoon of September 20th and went above minor flood stage of sixteen point five feet by the early evening hours. The river continued to rise at steep fashion through the night and went above moderate flood stage of seventeen feet a little past midnight of September 21st. The Taiya River crested in the early morning of September 21st at seventeen point sixty-four feet. The rain slowly diminished through the rest of the morning hours and the river slowly receded to be below minor flood stage by the afternoon of September 21st. The National Park Service reported that there was some flooding Chilkoot trail.

Wider weather episode

A deep trough of low pressure with a long fetch from the North Pacific to the Gulf of Alaska produced a very strong and wet weather system. The atmospheric river slammed into northern southeast Alaska panhandle from September 20th through the 21st. The northern inner channels received moderate to heavy rainfall with stations reporting one to two inches of at sea level with more at higher elevations. Along with the heavy rainfall there was very high freezing levels which ranged from eight to ten thousand feet. These high freezing level accompanied with the heavy rain increased the runoff from any snow left in the mountains and ice melt from area glaciers. All of the rain and snow/ice melt produce moderate flooding along the Taiya River and flooded the Chilkoot trail, part of the Klondike Gold Rush National Historical Park, near Dyea Alaska. The river crested around seventeen point sixty-four feet which is above moderate flood stage of seventeen feet in morning hours of September 21st.

View location on OpenStreetMap → (59.4820, -135.3423)

Source: NOAA Storm Events Database, event_id 857412. Narrative written by the NWS forecast office that issued the report.