* WHAT...For the Frost Advisory, temperatures as low as 33 will result in frost formation. For the Freeze Watch, Sub-freezing temperatures as low as 29 possible with warmer temperatures near Saginaw Bay. * WHERE...Arenac and Gladwin Counties. * WHEN...For the Frost Advisory, until 8 AM EDT this morning. For the Freeze Watch, from late tonight through Saturday morning. * IMPACTS...Frost and freeze conditions could damage or kill crops and other sensitive vegetation if left unprotected.