* WHAT...Sub-freezing temperatures as low as 28 over the southwestern Texas Panhandle, and as low as 30 elsewhere. * WHERE...Bailey, Cochran, Crosby, Floyd, Hale, Hockley, Lamb, Lubbock, Lynn, Terry, Yoakum, Briscoe, Castro, Parmer, and Swisher Counties. * WHEN...From late tonight through Saturday morning. * IMPACTS...Frost and freeze conditions could kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing. Take steps now to protect tender plants from the cold.