The watch will remain in effect until late Thursday.
WTHI News-10 Meteorologist David Wire told The Brazil Times the system heading this way could produce a significant amount of snow.
"I'm looking at the 5-inch mark (for Clay County)," Wire said. "I'm saying 3-5 inches for the Wabash Valley, but there are going to be some 6-inch areas to the south."
NWS predicted a total of 3-6 inches of snow, with the heaviest of snow expected south of Interstate-70. In addition, winds will increase on the backside of the storm, which could cause blowing and drifting snow.
According to NWS, roads could become slippery due to snow and visibility will be reduced. Travel could become hazardous and rush hours will be affected.
NWS stated a "winter storm watch means there is a potential for significant snow, sleet or ice accumulations that could impact travel."
The organization said in addition to the snowfall Thursday, below zero wind chills were expected at times from Thursday night into Saturday morning. Snow showers could be possible Saturday and again Sunday evening through Tuesday.
"The real story is the cold," Wire said. "This is a cold system that is going to move through here. (Friday) is going to be one of the coldest days that we've seen so far this season."
Wire said temperatures have stayed "below average" through January so far this season.
"The first week of January ended up being OK," he said. "But these temperatures are below average and I see temperatures staying below average through the end of this month."
The service called for no snowfall Friday, with a high temperature expected in the mid-teens. It also called for a 20-percent chance for snow showers Saturday, with highs in the mid-20s. It also stated there was a 20-percent chance of snow Sunday evening and a 40-percent chance Monday.
"This is kind of a one-day event," he said. "But we've got back-to-back systems. Monday, Tuesday and Wednesday could see another inch of snow."
Other counties in the storm watch include Fountain, Montgomery, Boone, Hamilton, Vermillion, Parke, Putnam, Hendricks, Marion, Hancock, Henry, Vigo, Owen, Morgan, Johnson, Shelby, Rush, Sullivan, Greene, Monroe, Brown, Bartholomew, Decatur, Knox, Daviess, Martin, Lawrence, Jackson and Jennings.