Raleigh, N.C. — Another blast of cold air expected to descend on the Triangle by Friday afternoon could bring snow, making for a potentially messy evening commute, WRAL forecasters said.

The air mass, which was hovering in the upper atmosphere over British Columbia, Canada, on Wednesday, should move into the region by 3 p.m. Friday. Depending on the temperature, the conditions could be ripe for snow, sleet or a wintry mix.

If temperatures are cold enough, that could mean icy, slick patches on roadways. The Town of Cary planned to start brining roads Thursday morning.

WRAL meteorologist Mike Maze said this system will be different than the vigorous storm that dropped snow and freezing rain in the region last week. By comparison, the next one will be “puny.”

“Last week’s was loaded down with moisture, but it didn’t have the cold air,” Maze said. “This one is loaded down with cold air but not a lot of moisture. What will fall will be frozen.” More Info     Protecting homes, cars and pets in cold weather

It’s too early to tell how much, if any, snow or sleet will fall. Residents just need to keep an eye on the sky, WRAL meteorologist Nate Johnson said. Friday’s forecast calls for temperatures in the 30s.

“The timing of this is going to be tricky,” he said. “They need to make a decision in the morning about whether they will need to change their routine.”

Early Wednesday, temperatures plummeted into the low 20s and upper teens across central North Carolina as bitterly cold air continued to stream into the eastern half of the U.S. from Canada. 

The frigid temperatures sent hundreds of Triangle-area homeless into shelters overnight. The Raleigh Rescue Mission on Hargett Street reached capacity.

The men's shelter at the Durham Rescue Mission overflowed Tuesday night, with 200 beds taken and another 53 men sleeping on the floor.

"Every year, somewhere in our country, we hear in the news of someone freezing to death because they had no warm place to stay during the cold nights," shelter founder Ernie Mills said. "I don't want to hear of news like that in the Triangle."

In the Midwest, authorities suspect exposure to bitter temperatures has played a role in at least four deaths so far.

Among the coldest temperatures recorded Tuesday was 35 below at Crane Lake, Minn., a National Weather Service forecaster said early Wednesday.

Cold weather also affected cars. AAA Carolinas reported a 40 percent increase in roadside assistance calls Wednesday, compared with a typical January day.

After dipping into the upper 20s again overnight, highs Thursday should top out in the upper 30s. 

Temperatures will gradually rise through the weekend and into the early part of next week.

"The weekend's great," Maze said. "And we should be into the 60s by Tuesday."