Expect frosty morning in Tri-Cities

The first big frost of the season is expected Wednesday morning in the Tri-Cities.

The National Weather Service has revised its forecast for the Tri-Cities, now saying that temperatures could dip well below freezing to 28 degrees.

Weather conditions will make frost-covered lawns, trees and windshields likely, according to the Washington State University’s AgWeatherNet.

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 all are required for frost and all are forecast for Wednesday morning across Washington state, said AgWeatherNet meteorologist Nic Loyd.

“The last time we saw such an expansive frost was in April,” he said.

This story was originally published November 3, 2015 at 12:17 PM with the headline "Expect frosty morning in Tri-Cities."