* WHAT...For the Frost Advisory, temperatures as low as 33 will result in frost formation. For the Freeze Warning, sub-freezing temperatures as low as 30 expected. * WHERE...The Triangle, southern Piedmont, Sandhills, and Coastal Plain. * WHEN...For the Frost Advisory, from 3 AM to 8 AM EST Saturday. For the 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. Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. Take steps now to protect tender plants from the cold.