* WHAT...Temperatures of 32 to 36 degrees will result in frost formation. * WHERE...Northern and Central Coast Range Valleys and Mountains of Oregon, Eastern Portland/Vancouver Metro, Lower Columbia River and Cowlitz River Valleys, Central Willamette Valley, Tillamook County Coast, Central Coast of Oregon, Tualatin Valley, Portland West Hills and Chehalem Mountain, Willapa Hills, North Clark County Lowlands, and South Washington Cascade Foothills. * WHEN...From 1 AM to 9 AM PDT Friday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.