An unusually cold air mass has swept across the Sunshine State, and a late-season frost is likely Friday night across inland areas of the panhandle and northeast Florida.

Thursday's cold front marked the arrival of an air mass that is running 10 to 15 degrees below normal, and in some areas near record-setting for this time of year. Clearing skies and lightening winds across the northern third of the state will make conditions favorable for frost formation across inland and rural areas roughly north of a line from Cedar Key to Jacksonville.

A Frost Advisory has been issued by the National Weather Service offices in Mobile, Tallahassee and Jacksonville where action is urged to prevent damage to sensitive plants, such as covering them up or bringing them inside. Temperatures in the advised locations are expected to fall into the lower and middle 30's by daybreak Saturday. Elsewhere across Florida, overnight lows will generally be in the 40s and 50s.

The cooler-than-normal weather is expected to last into the start of the weekend, followed by some moderation in temperatures by Sunday.