Climate Watch

By Rick Thoman Alaska Climate Specialist Alaska Center for Climate Assessment and Policy International Arctic Research Center/University of Alaska Fairbanks

In this last Climate Watch installment on El Niño and Nome climate, we’ll look at how seasonal precipitation totals (melted snow plus any rain) has played out over the past 50 years.

This is not quite the same as seasonal snowfall, since November rain is significant in some years, and — while rare —it still can happen.

The graphic shows the total November through March precipitation during the 16 El Niño winters since 1976/77 as a difference from average. The most striking feature is that in many El Niño seasons the total precipitation during these five months is not too far from average. That is, El Niño is overall not a useful predictor of cold season precipitation.

However, while there have been no especially dry El Niño winters, a few seasons had a lot of precipitation. In most of these seasons, the higher than usual precipitation was distributed over two or three months, implying multiple storms during the winter, though overall there is no tendency for more storminess (or at least the number of windy days) than average during El Niño seasons. The 1979/80 winter was different: Over 2.5 inches of rain fell the first two weeks of November 1979 and this accounted for most of “excess precipitation”; in fact, precipitation (and total snowfall) the remainder of the winter was not too far from average. significantly tilts the odds to favor a comparatively mild winter, but doesn’t provide us with any clues for more or less precipitation, snow or storminess relative to average over the course of the winter season.