UPDATE: A Winter Storm Watch has been issued for the northern half of Oconee, Pickens, and Greenville counties, valid Saturday evening through noon Sunday. 1 to 4 inch snow/sleet accumulations will be possible at the highest elevations. Roadways will become slippery and traveling will be dangerous overnight Saturday into Sunday.
A few hours of wintry weather may greet some residents of the Upstate Saturday afternoon into Saturday night.
A quick-moving trough of low pressure in the upper atmosphere over the northern Rockies Friday afternoon is expected to approach the Deep South on Saturday evening. Moisture from the Gulf and Atlantic ahead of the system is going to encounter an initially cool and dry air mass over the Upstate Saturday afternoon. As precipitation falls into the dry air, the temperature cools down and this is the reason why a blend of sleet, snow, and rain is becoming more probable.
Air temperatures are likely to be 40s for a time early Saturday afternoon, but are likely to fall into the 30s after the precipitation starts, some time between 1 and 3 PM. Significant accumulation of any sleet or snow along or near Interstate 85 is unlikely because temperatures are expected to stay above freezing. The temperature may fall closer to freezing in the mountains of Pickens, Oconee, and Greenville counties, where a light accumulation is possible Saturday evening, potentially leading to slick roads there.
Enough warm air should change the precipitation over to rain late Saturday night even in the mountains. The rain is forecast to end across the Upstate early Sunday morning and some sun is expected by Sunday afternoon.