WYFF and other weather forecasts vary for this weekend's snow and ice totals from 'Diego'

How much snow and ice should residents in Greenville, Anderson and other parts of the Upstate expect this weekend? It depends on which forecaster you trust — and when you check the latest predictions.

Meteorologists with the National Weather Service, WYFF-TV, other Upstate stations and national outlets such as The Weather Channel and AccuWeather are all predicting that a major winter storm will affect the area from Saturday night into Monday.

Their descriptions of the storm have been at times dire.

The National Weather Service warned that the storm could be a "once-in-a-generation event." A story posted on AccuWeather's website Thursday morning said it "may hit like a sledgehammer." The Weather Channel has dubbed the approaching system "Winter Storm Diego."

More:Greenville snow forecast: What we know

More:Anderson winter weather forecast: 'Particularly bad' Sunday

But details of the forecasts vary in snow and ice totals.

And the forecasts have fluctuated.

The National Weather Service issued an outlook on Thursday morning calling for Greenville to receive around 5 inches of snow, with about 4 inches falling in Clemson and 2 inches in Anderson. The weather service also prediced 14-16 inches of snow in portions of the North Carolina mountains.

But by Thursday afternoon, the weather service had revised those totals downward. The afternoon forecast predicted that Greenville will see only 2 inches of snow, with less than an inch in Clemson and no measurable snowfall in Anderson. The updated forecast still calls for parts of the North Carolina mountains to receive around a foot of snow. 

In a midday broadcast Thursday, WYFF meteorologist Dale Gilbert said 3 to 6 inches of snow may fall north of Interstate 85, with 6 to 12 inches or more in the Upstate mountains. 

"A swath of North Carolina could exceed some of the record amounts in the past," Gilbert said. "There's the potential for a foot to over 18 inches of snow."

WSPA meteorologist Christy Henderson said Thursday morning that the North Carolina mountains could receive "huge totals" of snow of up to 20 inches.

Fox Carolina meteorologist Nicole Papay offered a more restrained prognosis on Thursday, saying the Upstate "will see a wintry mix with some light snow accumulations."

Ice may pose the greatest threat from the storm in Anderson and other areas south of Interstate 85.

"The potential exists for a corridor of significant ice accumulation across the areas south of Interstate 85 Saturday night and Sunday morning," states a hazardous weather outlook issued by the National Weather Service. According to the weather service's afternoon update, Anderson may receive about .05 inches of ice.

Henderson echoed the concern about ice, according to a video posted on WSPA's website.

"You get south of the interstate, that is where damaging ice accumulations become a little more likely," she said.

Follow Kirk Brown on Twitter @KirkBrown_AIM and email him at kirk.brown@independentmail.com