PITTSBURGH — Snow showers could slow down your plans on Thursday. Light snow develops early in the morning causing delays during the morning commute with a period of steady snow showers continuing from mid-morning through noon. Scattered off and on snow showers will also be falling during the evening commute making it tough for road crews to keep up. A Winter Weather Advisory has been issued for Allegheny, Butler, Washington, Beaver, Westmoreland, Fayette, Armstrong, Lawrence, Greene, Indiana, Clarion, Venango and Forest counties and a Winter Storm Warning has been issued for the ridges of Westmoreland & Fayette counties and for Somerset, Preston, Tucker, and Garrett, MD. The next big system is expected this holiday weekend. A brief wintry mix is possible early Saturday morning before warmer temperatures change the mix to rain.