The heavy lake-effect snow band that pummeled areas south of Buffalo much of the day Friday shifted north during the afternoon and evening hours, before drifting back south again with even more vigor, as weather forecasters predicted.
"We had a heavy, lake effect snow band in the vicinity of the Buffalo Metro area," said Kirk Apffel, a National Weather Service meteorologist at the Buffalo Niagara International Airport.
"It started late afternoon. It was focused more across the Southtowns and this evening, right around sunset, it slipped northward and now it's focused on downtown and heading into the Northtowns, as of 7 p.m.," Apffel said shortly before 8 p.m. Friday.
The snow band has been producing accumulation rates of about 2 inches of snowfall an hour, which helped make Friday evening's commute a difficult one for motorists, he added.
As of about 5 p.m., the lake-effect snow band over Western New York had dropped 11.5 inches in places like Marilla and 9.4 inches in Hamburg. More than 7 inches of snow was recorded at the airport as of 7 p.m. Friday.
Apffel said accumulations across the region vary – because the band is moving.
"Obviously, it doesn't take very long for the snowfall totals to add up," he said.
"It's a very narrow and intense band," Apffel added.
Forecasters had expected the band to graze the Northtowns but some areas north were expected to see slightly higher accumulations of snowfall than originally forecast before the band switches direction back to the Southtowns again later tonight.
"The Northtowns will get a little more than a grazing. It might get up into that 5 to 6 inches range, though there's going to be a very sharp cutoff on the northern fringe (of the snow band)," said Apffel.
Still, areas of Amherst and the Town of Tonawanda are expected to see significantly less snowfall than has already hit the Southtowns, Apffel said.
"There's going to be a very sharp cutoff. In other words, some areas are going to get significant amounts. In northern Erie, we're going 5 to 10 inches, but the far northern areas will see significantly less," he added.