GALLERY: Winter storm hinders Iowa travel

UPDATE: A winter storm with heavy snow and high winds is not only affecting travel across much of the state, it's led Polk County Jail officials to cancel visit to inmates.

The jail in Des Moines canceled visitation for Wednesday, although it expected to resume visitation on Thursday.

The Iowa Department of Transportation's road weather information system shows sustained winds of 15-25 mph across central Iowa and gusts to around 35 mph. Portions of south-central Iowa had more than 7 inches of snow.

As the storm tracks eastward across Iowa, whiteout conditions are reducing visibility.

Transportation officials report significant slowdowns and backups in central and eastern Iowa as crashes and jackknifed trucks block roads.

Winter storm warnings and advisories remain in effect. After the snowfall ends, temperatures will fall, with readings below zero by Friday in much of the region.

Many school districts across the state also cancelled classes Wednesday.