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Hydroclimate Report Water Year 2021

Michael L. Anderson | December 31st, 2022


Water year (WY) 2021 added to the climate change narrative with extreme dryness leading to record setting drought conditions. In both precipitation and temperature, there were new extremes with a record dry and warm spring being most notable. Late fall onset occurred again this year arriving in late November starting the seasonal snowpack on very dry soils. The WY ended with 48 percent of average precipitation statewide making it the second driest year in 126 years of record. It was also second warmest for statewide average temperature. For two-year totals, WY 2021 set a record, recording less precipitation than WY 1977. There was only one significant storm in the WY in late January which included low elevation snow and very strong damaging winds. The April 1 statewide snowpack registered 62% of average. Peak snowpack at 64% of average occurred the week before April 1. Runoff from the snowpack was far below expectations due to the dry antecedent conditions and record dry and warm spring. The lack of runoff resulted in the need for emergency drought response measures.

Keywords

climate change, water supply forecasting