By Rachel Webber, College of Agricultural, Human & Natural Resource Sciences
PROSSER, Wash. – Washington state weather could hardly make up its mind in 2013, as temperatures flipped from unusually warm to cool by the end of the year.
Overall, 2013 temperatures were only slightly above average, since conditions in January and late 2013 were cool enough to partially balance the abnormally warm growing season. The mean high temperature in July was the warmest on record for any month, while the mean low temperatures were the warmest on record for the months of August and September.
Unlikely activity
Typically active and stormy periods, such as January and October to December, were particularly uneventful in 2013. In fact, most of the active weather came during the unlikeliest time of the year.
“The Sept. 15 severe weather outbreak had an adverse effect on agriculture in eastern Washington,” said AgWeatherNet Director Gerrit Hoogenboom. “Powerful winds flattened entire corn fields in Franklin County while also blowing apples off of trees in the lower Columbia Basin.”
A Web based, publicly available system, AgWeatherNet provides access to near-real-time weather data and value-added products from Washington State University’s statewide weather network, along with decision aids for agricultural producers and other users.
Fall wind and rain
A winter-like storm brought heavy rain, high wind and mountain snow to Washington Sept. 28-30. East Olympia received nearly three inches of rain in 24 hours on Sept. 28, while winds gusted to 71 mph at Huntsville. Much of western Washington was wetter in September than in October and November combined, while a few locations received almost as much rain during the 3-day superstorm as was recorded during the subsequent two months.
Earlier in September, an unusual, late-season severe weather outbreak spawned torrential rainfall, gusty wind and large hail on Sept. 15. Parts of eastern Washington received upwards of one inch of rainfall in only 15 minutes, and winds gusted to more than 60 mph in areas near strong thunderstorms.
Hot, cold and dry
Earlier on Sept. 15, College Place near Walla Walla registered a high temperature of 101 degrees, which is the latest date AgWeatherNet has ever recorded a 100-degree temperature.
“During the period from April to September, Prosser’s mean temperature was a whopping 1.7 degrees above average and 2.4 degrees warmer than normal at night,” said AgWeatherNet meteorologist Nic Loyd. “By contrast, Prosser’s December mean low temperature was 7.2 degrees below average and the largest monthly temperature departure in four years.”
2013 was also a rather dry and benign year. Vancouver and Seattle experienced a net precipitation deficit in 2013. At Vancouver, for example, the annual precipitation minus evapotranspiration value was +7.53 inches in 2012 but only -12.24 in 2013.
Temperature extremes
Notable weather also occurred at other times during 2013. In May, Washington experienced one of the most drastic pattern reversals ever to occur in the course of a spring month. An early heat wave sent temperatures soaring into the upper 90s in parts of eastern Washington.
However, much cooler and wetter weather arrived for the second half of the month. High temperatures on May 22 were only in the 40s in some areas of central Washington that had climbed into the 90s earlier in the month. Despite the fact that temperatures normally increase during May, Prosser’s average high temperature during the final 12 days of May (66.3 degrees) was 17 degrees cooler than during the first 12 days of the month.
During the early summer, a major heat wave on July 1-2 caused temperatures to soar as high as 108 degrees in what was the earliest heat wave of that magnitude since 1992.
Following a cool and uneventful October and November, temperatures at Pullman plummeted to -12 degrees during an arctic outbreak in early December. High temperatures at Prosser were below freezing for nine straight days, while Mount Vernon recorded low temperatures below 20 degrees for four consecutive nights.
Contacts:
Nic Loyd, WSU AgWeatherNet meteorologist, 509-786-9357, nicholas.loyd@wsu.edu
Rachel Webber, WSU CAHNRS Communications, 509-335-0837, rcwebber@wsu.edu