Update (1:25 p.m. Friday, Jan. 20):

The National Weather Service in Des Moines has canceled the winter weather advisory for Ames.

The National Weather Service in Des Moines has issued a winter weather advisory for Ames until 6 p.m. Friday.

Light snow is expected to continue through 9 a.m. Another round of snow is expected by late morning and will continue into the afternoon.

The city of Ames announced Thursday afternoon that its snow ordinance would go into effect at 1 p.m. Friday. All cars should be removed from snow routes by that time.

The NWS forecast for Ames called for less than half an inch of accumulation overnight and an additional 2-4 inches today.

Easterly winds of 10-15 mph will lead to minor blowing and drifting and could reduce visibility to one half mile at times. Wind chills will remain near zero throughout the day.