* WHAT...For the first Freeze Warning, sub-freezing temperatures as low as 31 expected. For the second Freeze Warning, sub-freezing temperatures as low as 28 expected. * WHERE...The northwest Piedmont, northeast Piedmont, and northern Coastal Plain. * WHEN...For the first Freeze Warning, until 8 AM EST this morning. For the second Freeze Warning, from 1 AM to 8 AM EST Sunday. * IMPACTS...Frost and freeze conditions could kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing.