People across parts of Alabama woke up Friday morning to snow blanketing their streets and police warning of impassable roads. The winter storm forecasters have warned of through the week from Huntsville to Birmingham began sometime over night.

Due to the vagaries of weather in Alabama in winter, winter precipitation may happen in the far reaches of northern part of the state − or there may be a mix of cold rain and snow flurries as far south as the Highway 80 corridor.

The winter weather advisory takes effect at 6 a.m. Thursday. Forecasters say 2-4 inches of snow could fall, with some sleet mixed in at the outset of the storm.