It’s still fall, but winter is getting revved up.
Unseasonably cold air is expected to sweep into the area overnight into Monday and bring with it the potential for November snow showers.
National Weather Service meteorologist Jason Frazier said on-and-off rain on Sunday could change over to snow flurries between about midnight and 2 or 3 a.m. in Allegheny and Westmoreland counties.
A winter weather advisory will be in effect from 1 p.m. Monday to 1 p.m. Tuesday for the Westmoreland and Fayette ridges, where 1 to 3 inches of accumulation is expected along with wind gusts up to 35 mph.
An advisory began at 7 p.m. Sunday and will also be in effect until 1 p.m. Tuesday for Mercer, Venango and Forest counties, where between 3 and 5 inches are expected with wind gusts to 40 mph.
In Allegheny County, light snow showers with accumulation from a trace to an inch is expected, according to the National Weather Service.
There may be some light snow Monday morning and the chance for on-and-off showers will continue throughout the day and on Tuesday, Frazier said. The amount of accumulation the region sees could vary based on a variety of factors, including ground temperature, intermittent sunshine and the location of forecasted bands of snow coming off Lake Erie, he said.
Some areas may see an inch of snow, while others see less, or more, depending on those factors.
But everyone is expected to see high temperatures about 15 degrees below the average for this time of year, Frazier said. Forecasts for Monday and Tuesday show high temperatures in the upper 30s with breezy conditions. The average high temperature at Pittsburgh International Airport for this time of year is 53 degrees with a low of 36.
Wind chill likely will be a factor both days.
“We know it can happen in this time of year,” Frazier said. “That doesn’t mean we’re necessarily ready for it.”
Time to dig the winter clothes out of the closet, at least for a couple days, and brush up on winter weather driving safety, especially with the potential for slippery conditions and the forecasted bands that could reduce visibility.
“This is the first snow of the season, so people may need to get themselves reacclimated to this,” he said.
The higher elevations of Westmoreland County are under a winter weather advisory from 1 p.m. Monday to 1 p.m. Tuesday. In that area, there’s a potential of 2 to 4 inches mainly at the highest elevations, Frazier said.
In true Southwestern Pennsylvania fashion, the early burst of winter weather won’t last long. Temperatures are expected to get back to average later in the week.
