*This story has been updated to include information about Columbia Public Works' progress treating roads Sunday afternoon.
UPDATE: Columbia Public Schools canceled school Monday because of hazardous road conditions.
COLUMBIA — Up to half a foot of snow is expected to coat Columbia on Tuesday as a low-pressure system moves in to mid-Missouri, just as Friday's icy conditions are getting cleared up.
Columbia residents can expect 3 to 6 inches of snow starting Tuesday morning, said Ben Miller, a meteorologist with the National Weather Service forecast office in St. Louis. Areas north of Interstate 70 will receive the most precipitation, Miller said.
Commuters should expect normal wintertime driving conditions, as snowfall is predicted to last until late Tuesday night, Miller said.
While priority routes and second priority routes were generally passable, about half of residential roads were treated by noon Sunday, said Teresa White, a marketing specialist for the Columbia Public Works Department.
"When more precipitation hits or temperatures drop overnight, some of those resources may have to be pulled back because of refreezing to the first and second priority routes," White said.
*As of 4:30 p.m. Sunday, street crews had treated more than 95 percent of residential roads and were finishing up the final areas in southern Columbia. The Public Works department urged morning commuters to use extreme caution and allow extra time for travel because some slick patches still exist.
Columbia Public Schools canceled school Monday because of hazardous road conditions.
Friday's freezing rain might have complicated the treatment process by potentially washing away pre-treatment salt brine that was applied Thursday night in anticipation of slick conditions, White said.
A Missourian article published Saturday detailed the icy conditions brought on by the storm. Treatment of roadways ahead of time was not enough to prevent about 100 accidents in the span of two hours Friday night, according to a news release by the Public Safety Joint Communications Department.
Current treatment actions will also act as pre-treatment ahead of the snow expected Tuesday morning, White said.
"Preparation that we're putting down now with salt on the roads will help with additional precipitation," White said. "We have that extra time to make the roads passable and safer before more precipitation hits on Monday night and Tuesday."
Current information on road crew progress for residential areas is available at comosnow.com.
The National Weather Service in St. Louis is also examining another weather system that it expects will bring snow Friday or Saturday, Miller said.
"It looks like the unseasonably cold conditions are going to last for at least another week or two," Miller said.
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