At first glance, the title of this blog may look like a mistake. How can record warmth lead to cold weather advisories, like Wednesday night's Frost Advisory (and Freeze Warning for the northern counties of Mecosta, Newaygo and Oceana)? After all, the typical minimum temperature this time of year is slightly below freezing; why should there be any special advisories about "normal" weather conditions?
The primary reason for the National Weather Service to issue a Frost Advisory and/or a Freeze Advisory/Warning is to alert people who have tender vegetation in the ground that their plants might be damaged. Typically in late March, that's not a problem in West Michigan. Plants and trees are weeks away from budding. But not this year.
Last week's spate of unprecedentedly warm weather -- nine consecutive record-setting days, several days with daytime highs in the 80s and nighttime lows in the 50s -- caused vegetation to develop rapidly. Many trees and plants have developed buds and begun to flower. They're now vulnerable to damage from frost and/or freezing conditions. That's why the National Weather Service has begun issuing cold weather advisories. It isn't because the "cold" temperatures are abnormal. It's because last week's warm temperatures have created a situation where seasonably cold weather can do substantial damage. Because frost and freezing conditions are fairly common in West Michigan for at least the next month and a half, you can expect to hear about many more Frost/Freeze Advisories in the days and weeks to come.