1.   Areas of freezing rain will linger in some of the deeper valleys of eastern Washington, Oregon and Idaho where a shallow layer of Arctic air remains trapped.

2.   As this corridor of moisture rides over a shallow layer of sub-freezing air, an icy glaze could coat northern Iowa and southern Minnesota.

3.   A light mix of snow and rain began to fall into a shallow layer of sub-freezing air near the ground.

4.   A shallow layer of chilly, moist air will be wedged along the Northeast Coast from Delaware to central Massachusetts.

5.   A wintry mix of precipitation will develop in the central Plains as warm, moist air just above the surface overruns a shallow layer of arctic chill.

6.   A shallow layer of arctic air will remain across eastern sections of the northern Plains, while readings trend upwards from recent days in western areas.

7.   Farther northwest, in some valleys where a shallow layer of sub-freezing air clung to the ground, raindrops froze on cold objects, causing an icy glaze.

8.   Farther south, patches of freezing rain and sleet will develop near the southern Appalachians, where a shallow layer of cold air will be overrun by warmer air.

9.   Freezing rain occurs when snow melts into raindrops and re-freezes in a shallow layer of cold air near the ground, creating a glaze condition.

10.   Freezing rain can occur when a shallow layer of cold air hugs the surface while warmer air lies above.