Madison declared yet another snow emergency Sunday, prompting many event cancellations and closings throughout the area.

The National Weather Service issued a winter storm warning for Madison and predicted three to six inches of snow accumulation by Monday. The storm also delivered a wintry mix of freezing rain and snow early Sunday morning.

The weather forced presidential hopeful U.S. Sen. Hillary Clinton, D-N.Y., to postpone a scheduled appearance at a “Solutions for America” rally at the Monona Terrace Sunday night. The event was rescheduled for 8:15 p.m. Monday.

City and county officials urged people to stay off area roads because of slush and ice that created hazardous driving conditions.

“Although City crews are working hard to make our streets as safe as possible, unnecessary travel should be avoided if at all possible,” Mayor Dave Cieslewicz said in a statement.

Madison Metro Transit stopped its services at 8:30 a.m. Sunday, the second time in February the buses have shut down because of extreme weather conditions.

All UW-Madison libraries were closed by 1 p.m., and Memorial Union and Union South closed at 8 p.m. The Athletic Department cancelled the men’s hockey event “Skate with the Badgers” and “Bucky’s Buddies,” a women’s hockey skills clinic at the Kohl Center.

University officials said campus is expected to be open for business and classes Monday.

According to a statement, the city’s Streets Division crews opened storm drains to collect Sunday’s rain before the snowfall. Salt and sand were spread on main streets to keep roads open for emergency vehicles.

“We are planning for heavy wet snow which will require extra time and effort to plow, especially after all of the rain,” said Streets Division Spokesperson George Dreckmann.

Plowing of main streets continued throughout Sunday and all streets were plowed at midnight, with additional plowing planned for Monday if necessary.