Along the lines of wondering what our winter will be like, I attended the 21st Winter Weather Forecast Conference on Saturday at OMSI.
Andy Bryant from the National Weather Service’s Portland office gave his agency’s forecast, much of it from the Climate Prediction Center. From November through March expect equal chances of above, below or normal temperatures and precipitation. Since it is a winter without El Nino or La Nina, it settles down to a neutral influence on weather patterns. He noted that in such years we receive our heaviest snowfall here in the lowlands. Remember December 2008? The Cascade snow pack will be below to near normal.
Kyle Dittmer from the Columbia River Inter-Tribal Fish Commission recognizes the absence of sea surface temperatures and utilizes sun activity and run-off of the past 20 years in the Columbia to make his forecasts. He forecasts a near-normal winter with rainfall/temperatures but expects some late-winter or early-spring weather action with maybe four snow events here in the city. Expect more extremes from wet to dry and back to wet like this autumn.
Jim Little, retired local TV forecaster, is trying to automate his forecast using objectively chosen analog years — looking at this year so far and looking back to past years to see what the winter was like. He predicts a cool November and December with near-normal rainfall, a wet January with near-normal temperatures, and February near normal on both aspects.
