Winter storm smacks Sisters hard

On Wednesday, December 14, Old Man Winter took dead aim on Central Oregon and dealt the region a staggering blow.

The wintery blast closed schools, federal and state offices, as well as many businesses. For several days following the storm, citizens were still digging their way out of the massive snowfall in an attempt to regain some sense of normalcy.

Forecasters at the National Weather Service (NWS) office in Pendleton began to take notice of a rather disorganized mass of clouds in the eastern Pacific Ocean about 700 miles west of central California. It was the result of an extremely moist southwesterly flow of subtropical air that was starting to show some organization. The developing system was mentioned in the 10:09 p.m. PST forecast discussion for Sunday, December 11. The concern was that if this moisture-ladened air made landfall far enough north, it would overrun the deep cold that was already in place over Washington and Oregon, producing significant snowfall.

By Monday evening, December 12, forecasters decided that enough of the various computer models were showing a more northerly trajectory for the storm. So, at 6:57 p.m. they issued a winter storm watch. A watch means that there is a potential for heavy snow or significant ice accumulations. Part of the forecast that was issued during this time read, "...a strong and wet Pacific system is still on track to spread precipitation south to north across the region (Pendleton forecasting region) Wednesday and Wednesday night. Thus significant snow accumulations look to be possible over a good portion of the area."

As more of the models converged on the same solution, the watch was upgraded to a warning at 2:50 p.m. on December 13. A portion of the forecast issued at this time stated, "Precipitation amounts will be highest over Central Oregon where northeast to east low-level flow will result in upslope affects that will enhance precipitation development. Thus this area should see significant snows between 10 and 20 inches before precipitation decreases late Wednesday evening."

When residents awoke Thursday morning (December 15), they discovered that the NWS had pretty much delivered on its promise of copious amounts of snow. While official snowfall depths in many communities remain unavailable at this writing, several unofficial measurements were truly impressive.

Some parts of Bend registered up to 17 inches of snow, shattering a one-day record in December of 13 inches set in 1924. Redmond picked up at least a foot of the white stuff which, if it holds up, would break their previous one-day total of nine inches set on New Year's Eve 1992.

Here in Sisters residents in the Crossroad and Tollgate developments reported depths of about two feet. It's likely, however, that measurement included approximately four to five inches of snow that was on the ground previous to the December 14 storm. Reports of 17 inches were common in town. Sisters' one-day snowfall record of 16.5 inches occurred in December 1983.

The Climate Prediction Center is calling for an equal chance of above-normal and below-normal values for both temperature and precipitation during the month of January 2017 for Central Oregon.