Clear skies and calm winds allow temperatures to fall quickly, allowing us to get to the freezing conditions needed for frost. You also need a little bit of moisture in the air. Since ice is made of water, moisture is the obvious fuel you need if you want to scrape your car's windshield off in the morning.
As for Thursday night's frosty conditions, the National Weather Service has issued a Frost Advisory for all of southern Wisconsin through Friday morning. -BA
I live in Oregon and one time we had two Artic Blasts with very little snow so I expected to see a lot of frost but for some strange reason despite temps going to the upper single digits not a sing of frost.
ReplyDeleteWherever there was no snow the grass looked regular like a normal winter sunny day and I wouldn't have notice anything until opening the front door!
Is it the low dewpoints that prevented frost?
That's correct. Once we get into the heart of winter, there isn't a lot of moisture in the atmosphere to work with when it comes to frost formation. That's why we typically see frost in the fall and spring. -BA
ReplyDelete