Colorado will see its first “substantial” snowfall of the season on Saturday, according to the National Weather Service.

Just two weeks ago, NWS meteorologists confirmed the first snow on Colorado’s mountains. This weekend, meteorologists said the state’s northcentral peaks between four and nine inches of fresh snow.

A Winter Weather Advisory is in effect for Rocky Mountain National Park, the Medicine Bow Range, Summit County, the Mosquito Range and the Indian Peaks from 6:00 p.m. Saturday through noon on Sunday. according to NWS weather forecasters.

“Roads will become slippery in some areas, especially through mountain passes,” meteorologists said in the advisory. “Use caution when traveling.”

This weekend, snow won’t reach the lower elevations of the Front Range, metropolitan area and Eastern Plains, but meteorologists say areas below 9,000 feet (2,744 meters) can expect heavy rain and thunderstorms.