...Areas of frost expected late tonight... .High pressure will move east across Iowa tonight. North winds will bring frosty temperatures for late tonight and early Friday morning. ...FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 9 AM CDT FRIDAY... * TEMPERATURE...Lows will be primarily in the mid 30s. Valleys and hollows sheltered from the wind will be the most susceptible to frost. * IMPACTS...Frost could damage unprotected sensitive vegetation.