* WHAT...Temperatures as low as 33 will result in frost formation.
* WHERE...Huron, Lenawee, Livingston, Macomb, Monroe, Oakland, Sanilac, St. Clair, Washtenaw, and Wayne Counties.
* WHEN...From 3 AM to 8 AM EDT Saturday.
* IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.