The National Weather Service in State College has issued an ice storm warning for the Williamsport area, effective at 11 a.m. today through 1 p.m. Wednesday.

A winter storm watch issued earlier is no longer in effect.

According to the service, a complex low pressure system will strengthen as it moves north from the Tennessee Valley into the lower Great Lakes region.

Wintry precipitation in the form of snow and sleet will spread into the region from southwest to northeast today during late morning or afternoon.

Following a brief period of snow and sleet, a prolonged period of sleet will occur. It then will change to mostly freezing rain for the rest of tonight and into early Wednesday, before ending as mostly rain Wednesday afternoon.

A significant ice accumulation is expected for locations along and north of the turnpike up to about Interstate 80.

About a quarter of an inch of ice may accumulate from Harrisburg northward to State College, Williamsport and Berwick.

An inch or two of sleet and snow is possible before the change to freezing rain.

Minor ice and sleet accumulations will occur over the rest of the region as well.

An ice storm warning means a significant and possibly damaging amount of freezing rain is expected.

Ice accumulations may lead to snapped tree limbs and power outages. Travel on untreated roads will be dangerous or impossible.

Stay tuned to NOAA Weather Radio or www.weather.gov/statecollege for more information.