Arctic outbreaks headline state’s 2013-14 winter season

By Rachel Webber, College of Agricultural, Human & Natural Resource Sciences

PROSSER, Wash. – Better late than never. That’s a common sentiment among Washingtonians in the aftermath of a February of significant recovery in the mountain snowpack.

After a disappointing and relatively inactive fall and early winter, Mother Nature began to repay the snow debt owed to the Cascades. A stormy mid-February brought copious amounts of critically needed snowfall to the mountains, along with significant rain to western areas and mild and breezy conditions to the east.

“Many growers and other Washingtonians breathed a sigh of relief when heavy mountain snowfall finally materialized,” said Gerrit Hoogenboom, AgWeatherNet director. “Snowpack increased from about half of normal to near normal during February, such that summer water supplies should be adequate if we can continue to accumulate snow in the mountains during the spring.”

A Web-based, publicly available system, AgWeatherNet (http://weather.wsu.edu/awn.php) 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.

Prosser particularly cold

The other big weather story of February was the early-month cold air outbreak.

“The February deep freeze was the second arctic blast of the winter,” said AgWeatherNet meteorologist Nic Loyd. “Although these two events were far from unprecedented, they may have seemed more unusual than they actually were due to the conspicuous lack of arctic outbreaks in recent years.”

High temperatures on Feb. 7 were as cold as the mid-teens in parts of eastern Washington while several locations fell below zero at night.

Prosser experienced its coldest February temperature (1 degree on the 7th) since the historic 1996 arctic outbreak. Overall, Prosser experienced its coldest February since 1996 and the coldest February average high since 1993. Also, 2014 marks the first time in 20 years that Prosser’s average high was cooler in February than in January.

Pullman’s string of frigid nights

The winter season was generally cooler than normal as a result of the two arctic blasts. Early December was chilly and mostly dry. In fact, Pullman recorded low temperatures of below -5 degrees for five consecutive nights during that period.

However, a dirty ridge gained control of Washington’s weather in mid-December and remained anchored in place until early January. As a result, daytime temperatures were rather mild and conditions were drier than normal, with only periodic weak storms passing through the region.

Active and very mild weather arrived for the second week of January, as a series of storms brought rain to western areas along with wind and warmth to the east. The latter half of January was stagnant and dry, with cool and cloudy weather in the interior lowlands and mild and dry conditions in the mountains and at the coast.

Winter closes calmly

The unusual chill of early February gave way to the stormiest period of the winter. Despite mild temperatures in the east, much needed snow fell in the Cascades and notable rainfall affected western Washington. Finally, somewhat calmer and more seasonal weather closed out the month of February.

Overall, Prosser’s average low temperature this winter was the coolest since 1992-93. Even so, that fact is much more a testament to the recent lack of extreme cold than it is to this winter’s chill.

Contacts:

Nic Loyd, WSU AgWeatherNet meteorologist, 509-786-9357, nicholas.loyd@wsu.edu

Rachel Webber, WSU CAHNRS Communications, 509-335-0837, rcwebber@wsu.edu