[2] Columbia Basin Snowpack Feels El Niño

With the current El Niño nailing the West Coast with textbook conditions, a shift in the jet stream has channeled steady storms into California, leading to a milder, somewhat drier Northwest, and snowpack that may end up well below average for the Columbia Basin.

However, snowpack levels in the upper Columbia north of the border were still running right at average on Jan. 15, according to data from the BC River Forecast Centre, with the lower Columbia at 87 percent (up 5 percent from the week before).

Early snowfall had the upper Columbia running 138 percent of average by Dec. 1.

South of the border, early snows have given way as temperatures have risen. Upper Columbia watersheds were averaging 88 percent of average snowpack by Jan. 21, with overall precipitation at 95 percent.

Further south, the Yakima drainage was at 86 percent of average snowpack.

Idaho's Upper Snake region was running at barely half the average snowpack, while the Clearwater and Salmon River watersheds were slightly better, at 66 percent of average.

In Montana, the Kootenai and Flathead basins were at 82 percent of average snowpack.

Back on Jan. 8, the National Weather Service's River Forecast Center estimated that the Jan.-July water supply at the Columbia above The Dalles would be about 82 percent of normal. Snake River flows at Lower Granite were pegged at 75 percent of average. A new water supply forecast will be out in a few days.

This may improve a bit since precipitation levels above The Dalles have been nearly normal this month, 94 percent of average. Last month saw only 57 percent of average precipitation.

But the outlook for the region is for below-average precipitation and above average temperatures through March.

Ocean temperatures in the equatorial Pacific where the El Niños are born, have "eased slightly" over the past two weeks, according to the Australian Bureau of Meteorology, but are still more than 2 degrees C above average in many areas, "and generally remain above values observed at the peak of the 2006 El Niño event." The bureau's Jan. 20 update said temperatures are expected to remain above El Niño thresholds until the coming southern autumn (our spring).

The Jan. 18 update from NOAA's Climate Prediction Center also expects the El Niño to last into the coming spring. -B. R.

The following links were mentioned in this story:

California Regional Weather Server

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