By Linda Weiford, WSU News
PULLMAN, Wash. – Many Washington residents will wake up to Jack Frost nipping at their lawns, gardens and windshields tomorrow morning as the first widescale frost of the season descends on both sides of the Cascade range.
The chilliest air of autumn is expected to hit Wednesday morning, depositing frost in locations from Olympia to Pullman, said meteorologist Nic Loyd of AgWeatherNet, Washington State University’s statewide weather station network.
“With low temperatures predicted to drop to below 32 degrees, most areas of central and eastern Washington will get frost – as well as some areas in the western portion of the state,” he said.
And though some people may scowl at this frost-laden forecast, “it’s behind schedule by several weeks. For many places throughout the state, the average first frost arrives on Oct. 19,” he explained.
Since cold weather will be a major player in tomorrow’s late-arriving frost, just how chilly will it get? Temperatures early in the day are expected to dip into the low 20s in some areas, including Pullman-Moscow (Idaho), Spokane, the Yakima Valley, Ritzville and Ellensburg.
In most places, however, the mercury is expected to hover near 30 and then inch upward later in the morning.
Frost occurs when ice crystals are formed from water vapor near the ground, as opposed to snow crystals that form high in the clouds. Cold temperatures, clear skies and light winds are required for the cold air to settle near the ground where frost is created. By early tomorrow morning, all are expected to be present, Loyd said.
More frost is forecast for Thursday, though only in isolated pockets as temperatures creep up and clouds move in.
“The last time we saw such an expansive frost was in April,” he said.