PULLMAN, Wash. – In the Goldilocks story of May’s remarkable weather, the beginning of the month was too hot, the end was too cool, and the middle was just right.
Washington experienced a wide range of unusual, record-setting weather events in May, which were highlighted by two distinct episodes: a prolonged heat wave early in the month and an extended period of cool, wet weather at the end.
Historic finale
“If the spring of 2013 is viewed as a play with three acts, then May was certainly an historic finale,” AgWeatherNet meteorologist Nic Loyd said. “The marked transition from dry heat early in May to record wet and cold conditions later in the month makes May of 2013 singularly unique.”
High temperatures showed significant changes from well-above average to well-below average during the course of the month. Cold temperatures the morning of May 1 caused a monthly record-low temperature of 30 degrees at WSU Tri-Cities. However, rapid warming started a prolonged heat wave, during which time Orondo (north of Wenatchee) recorded high temperatures above 90 degrees for six consecutive days.
The middle of May was characterized by more seasonal and pleasant weather.
However, a cold storm system moved into Washington on May 21, and stalled for several days over the Northwest. May 22 was the coldest May day on record at places like Cowiche, which recorded a high of only 48 degrees. Prior, a sub-50 degree high at Cowiche had not been recorded later than April. Along with the cool weather came significant rainfall in typically arid south central Washington. Parts of the Yakima Valley recorded storm total rainfall amounts of up to 2.5 inches. The May 21 and 22 storm at Parker (near Yakima) was the heaviest May rain event on record, and one of the largest ever. Overall, both May and spring season were the warmest at Prosser since 2005, which halts the recent trend of cool springs.
Varied impact
“As expected, the dynamic spring weather has had varied impacts on Washington’s agricultural community,” said AgWeatherNet Director Gerrit Hoogenboom. “Although the early warmth allowed heat units to accumulate, it also stressed dryland crops in need of water. Later in the May, the cool and wet weather was generally beneficial to the eastern Washington wheat crop, although thundershowers on May 21 caused hail damage on the apple crop in the Quincy area.”
Although relatively normal by comparison, March and April also had their share of notable weather events. A potent March 20 storm delivered high winds, rain, and mountain snow to the state. Paradise, Mt. Rainier received about 2 feet during the storm, and even the Everett area experienced a late season snowfall on March 22.