Here’s your latest update on weekend weather for York, Chester, Lancaster

Weather experts say people in the Rock Hill region can expect a winter storm this weekend.
Weather experts say people in the Rock Hill region can expect a winter storm this weekend. AP

Forecasters scaled back their snowfall predictions Thursday but said they still expect a winter storm to affect the Carolinas, including the Rock Hill area, later this weekend.

Meteorologists say it is still too early to know exactly what type of precipitation – and how much of it – will fall in specific areas. It could be later Friday before they have a good idea on the key factor: the air temperature at various levels of the atmosphere.

It remains possible, as is typical with winter storms in the Carolinas, that the precipitation could fall mostly as rain in the Rock Hill area.

But as National Weather Service meteorologist Robbie Munroe said Thursday, “The bottom line is that a potentially very dangerous winter storm looms for much of the forecast area this weekend.”

The Weather Service earlier had described the system, which is expected to reach the Rock Hill area late Saturday, as a “once-in-a-generation event” for areas that experience mostly snow and ice. But by later Thursday, meteorologists trimmed snowfall predictions, amid signs that temperatures in mid and upper levels of the atmosphere will be warmer than first thought.

That would mean more of the precipitation would be in the form of sleet and freezing rain, or even a cold rain. The Weather Service issued a Winter Storm Watch for North Carolina counties, but no South Carolina counties were included initially. That is because, forecasters said, it appears as if Interstate 85 could be the dividing line between heavier frozen precipitation and lesser amounts.

The Weather Service had called for up to eight inches of snow in northern York County, but forecasts now predict two inches or less. Freezing rain could be a bigger problem.

The Weather Service is predicting more than a quarter-inch of ice accumulation across northern Chester, eastern York and northern Lancaster counties. That is the amount generally considered to be enough to cause widespread power outages.

Conditions are expected to be calm through Friday, with temperatures only reaching the lower 50s.

Another surge of cold air is forecast to move into the area Friday night, setting the stage for the wintry weather. Forecasters say precipitation should move into the Rock Hill area from the west late Saturday afternoon or in the evening. The heaviest precipitation is expected Sunday, although rain, sleet and snow are forecast to continue into Monday as secondary low pressure system moves through.

Steve Lyttle on Twitter: @slyttleSteve