* 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 28 possible. * WHERE...Cameron, Clearfield, Elk, McKean, Northern Clinton, Northern Lycoming, Potter, Sullivan, Tioga, and Warren Counties. * WHEN...For the Frost Advisory, from midnight tonight to 8 AM EDT Monday. For the Freeze Watch, from late Monday night through Tuesday morning. * IMPACTS...Frost and freeze conditions could kill crops, other