Meteorologists with the National Weather Service in Rapid City on Thursday replaced the winter storm warning for the Black Hills with a blizzard warning.

As of Thursday evening, as much as 8 to 18 inches of heavy, wet snow had been reported in parts of the Hills and up into Harding County, with an additional 10 to 18 inches of snow expected overnight in parts of the Hills and 12 to 24 inches expected above 5,500 feet in the Northern Hills.

Across the plains and in far northwest South Dakota, northeast Wyoming and west central South Dakota, 7 to 14 inches of additional heavy, wet snow was expected. The heavy snow was expected to be combined with strong winds and possibly bring down trees and power lines.

The snow caused some power outages Thursday afternoon in the Northern Hills. Barbara Zar, spokeswoman for Black Hills Power, said about 1,500 customers served by the Mountain View Substation near the Spearfish airport were without power.

Also, some areas from Spearfish to Deadwood and south to Strawberry Hill were without power Thursday afternoon. Zar did not have specific numbers of customers affected. She did not return a call Thursday afternoon seeking an update.

The National Weather Service said rain would change to snow Thursday evening and continue through Friday. Snow was forecast to be very heavy at times. The agency said that by Friday evening, storm total accumulations would range from 8 to 16 inches, with higher amounts possible in the hills south and west of Spearfish.

Along with the heavy snow, gusty northwest winds of 30 to 40 mph with gusts around 60 mph would create significant drifting of the snow and whiteout conditions.

Rain and snow began falling around the Black Hills late Wednesday night, with heavy rain falling in the Rapid City area about 2:30 a.m. Thursday.

Rapid City Regional Airport and Ellsworth Air Force Base both reported that about a half-inch of rain had fallen Thursday.

National Weather Service officials in Rapid City said there was a brief lull in the storm in the Rapid City area Thursday afternoon, but the precipitation was expected to resume Thursday evening.

Chris Murray, manager of Lynn's Dakotamart in Lead, said Thursday morning that customers had been steady throughout the morning, picking up staples such as bread, milk and eggs.

"They're also getting lots of snacks," Murray said.

The weather service said the storm would push east of the area this weekend, but there may be isolated thunderstorms Monday. Another system is expected to bring precipitation midweek before drier air returns.