PROSSER, Wash. – The pundits claim that timing is everything, and never was that more vividly the case than with Washington’s December weather. Despite very mild temperatures early in the month, colder weather made a belated arrival just in time for many locations to experience a white Christmas. Thanks to the arrival of a cold storm system on Christmas morning, snow fell across much of the state on Dec. 25.
In fact, December was both snowy in the mountains and unusually warm. Although the final December climate numbers seem to present a paradox, a closer inspection of daily weather shows that opposing trends can coexist given the right circumstances.
Active conditions prevailed for much of the month, so December was seasonally wet, windy and warmer than normal. However, periods of heavy snowfall led to an above normal Cascade snowpack. Heavy snow fell in the mountains on the 6th and 7th, and blizzard conditions followed Dec. 16-17.
“Some of the same storms that caused windy and warm conditions in eastern Washington also produced much needed snow in the mountains,” said AgWeatherNet meteorologist Nic Loyd. “Many lowland areas that began December with temperatures in the 50s received snowfall during the mid and latter part of the month, which was then preserved by a timely cold period after Christmas.”
Overall, December temperatures were well above average, especially in southeastern Washington. Prosser temperatures were 4.5 degrees above average during both day and night, making December the warmest since 1999 and the second warmest since at least 1989.
Remarkably, Long Beach experienced only one dry day – Dec. 30 – as the string of wet weather that began in mid October continued. Dec. 19 was a particularly rainy day, as Long Beach recorded nearly 3.5 inches of rain. Other notable December weather events included Walla Walla reaching 61 degrees on consecutive days (Dec. 4 and 5) and Wenatchee Heights recording a 63 mph wind gust on the 17th.
Despite the abnormal weather, Washington’s agricultural interests were not worried about December conditions negatively impacting regional crops.
“Luckily, December was generally free of any agriculturally adverse weather conditions like severe cold outbreaks,” said AgWeatherNet director Gerrit Hoogenboom. “Precipitation early in the month was beneficial to the winter wheat crop, while snow cover later in the month provided insulation from cold air temperatures.”
For more information on Washington’s December weather, please see the December Weather Review on the AgWeatherNet website, http://www.weather.wsu.edu, located under the AWN News link.