Autumn begins with cold air damming and a promise of rain

The forecaster's headache - also known as "cold air damming" (CAD) - is back in play again after a backdoor cold front slipped through Mecklenburg County Saturday on its way south. The surface weather map at 8 o'clock this Sunday morning shows the characteristic signature of the setup, with high pressure over New England pushing a cool wedge of surface air south across the Piedmont:

CAD is a headache to forecast as it typically lasts longer than most models predict. Locally it means easterly winds, which usher in moisture from off the cool Atlantic waters. Than usually brings cooler conditions, and today's high temperature will have trouble breaching the 80º mark. It can also mean more clouds than sun, but skies today look to be more sunny than cloudy.

Monday will dawn with low clouds in place but should wind up at least partly sunny. The autumn equinox arrives tomorrow afternoon, officially occurring at 2:19 p.m. and opening the door for those fall decorations to be set out. Afternoon high temperatures this week will begin near 80º and rise into the mid-80s through midweek.

Friday's blogpost provided the latest Drought Monitor graphic, which shows the increasingly dry conditions across much of Virginia. However, later this week a wet system will cross the Appalachians and provide for some significant rain. This graphic shows total rainfall amounts expected through next Sunday morning:

These rain amounts won't totally alleviate the drought, but they'll help!