2013 Run Timing Outlook and Forecast Summary: Chinook Salmon, Yukon River Delta

Update:The 2013 Yukon Chinook run timing outlook and forecast season concluded on July 14, 2013. The preliminary post-season analysis briefly describes the results of the forecast compared to the daily catch summary data at the Big Eddy and Middle Mouth Lower Yukon test fisheries managed by the Alaska Department of Fish and Game. The rest of this page remains for archival purposes.

The outlook is for a late run this year. The outlook and its associated forecast are based on the historical fish and environmental variables for which the 2013 data are given below. This timing information is intended for use by fishery managers, residents of Yukon River communities, and others to estimate when the Chinook salmon run will arrive on the delta and how it will develop through June and July 2013. Contained on this page are: (1) the modeled and estimated cumulative percents of the 2013 Chinook salmon run, (2) the cumulative CPUE for 2013, calculated by combining numbers from the Big Eddy, Middle Mouth and North Mouth test fisheries, compared to a selection of historical runs, and (3) marine environmental data that were used as inputs to the 2013 outlook and forecast model. At times during the course of the season after sufficient catch data have accumulated to evaluate the timing models, the timing forecast may be updated if the run turns out to be earlier or later than now expected.

Chart 1. Forecast of the cumulative percent of the Chinook run in Y-1 on each date from June 1 through July 15, 2013. Blue bars are forecasts of the 15%, 25% and 50% run percentiles derived from a model that approximates the migration of 1985. The cyan-colored line shows 2013 cumulative CPUE converted to estimated run percentages.

Chart 2. 2013 Cumulative test fishery CPUE (cyan) compared to historical CPUE data provided by Arctic-Yukon-Kuskokwim Region, Alaska Department of Fish and Game. The earliest run was observed in 1996 (green), and the latest run was observed in 2012 (orange). Also shown are the average of all runs between 1989 and 2011 except 2009 (blue) and the 2010 run (purple). Note that the run of 1985 (red) is the historical year which looks most like the 2013 forecast, as of May 31.

Near Real-Time Marine Environmental Variables

Air Temperature (°F) for Nome and Emmonak, AK

April Mean Air Temperature Emmonak:

April Mean Air Temperature Nome:

Marine Surface Temperature (°C) for 63.1°N 165.5°W

May Mean Sea Surface Temperature:

Average Sea Ice Concentration (%) for 62–63°N, 166–169°W

Mean Ice Cover, March 20–June 1:

Winds measured at Emmonak Airport (mph)