The Philadelphia area is preparing for another round of snow to hit during the night.

The snowfall would be the second the area has seen this week, an unusual occurrence in a winter that's been nearly snow-free thus far.

The biggest threat appears to be hazardous driving conditions overnight, from around midnight through around 6 a.m. Saturday, with snow, ice and a wintry mix threatening to hit much of eastern Pennsylvania and non-coastal parts of New Jersey.

Transportation officials were gearing up for plowing and salting operations. PennDot was warning motorists that clearing roads during a storm was a time-consuming operation, and drivers should use caution.

Forecasters were calling for a quick-moving storm to come through the area Friday night into Saturday before making its way further up the East Coast along the I-95 corridor on Saturday.

The National Weather Service has issued a winter weather advisory for 9 p.m. Friday through 10 a.m. Saturday.

Most of the area is expected to see two to four inches of snow, with places north of Philadelphia likely to see higher amounts and areas south of the city, particularly near the Jersey Shore, expected to get slightly less, according to the weather service.

Worst-case scenarios, however, call for up to seven or eight inches in the area.

The snow itself could be short-lived: Sleet and freezing rain are expected to be mixed in, with the storm shifting to primarily rain during the day Saturday.

That means roads may be slick Saturday morning. Some ice accumulation from freezing rain may occur, coating streets and sidewalks.

All precipitation in the area is likely to end by Saturday night, forecasters say.

The expected snow and wintry mix comes after overnight and early-morning freezing rain caused chaos on area roads Sunday morning and light snow hit the region on Wednesday.