* WHAT...Temperatures as low as 32 will result in frost formation. * WHERE...Northern and Central Coast Range Valleys and Mountains of Oregon, Lower Columbia River and Cowlitz River Valleys, Portland Metro Hills, Central Willamette Valley, Tualatin Valley, West Columbia River Gorge of Oregon above 500 ft, Clackamas County Cascade Foothills, Willapa Hills, North Clark County Lowlands, and South Washington Cascade Foothills. * WHEN...From 9 PM this evening to 10 AM PDT Friday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. * ADDITIONAL DETAILS...Areas that remain shaded through the morning will see frost linger the longest.