A strong winter storm system will move across the Midwest from Wednesday on into Christmas Day. This system will tap into a lot of moisture from the Gulf of Mexico. By 7pm Wednesday night, precipitation will be over Illinois and Iowa. The bulk of this system will be to the west of Indiana. When the precipitation arrives, the critical freezing level will be well north. This means that the precipitation will start off as liquid. As it fall through the colder air mass at the surface, it will refreeze. It could be in the form of sleet or freezing rain. As the surface temperature climbs above the freezing mark, the precipitation will change over to just rain. But before that happens, some ice accumulations will be possible.

The WRF model is very similar to the GFS. Northeast Indiana will see mainly snow showers on Wednesday night while Northwest Indiana will experience freezing rain and sleet.

The map below shows the areas of snow in magenta, freezing rain in the blue and rain in green. At 1pm Wednesday, the system should be bringing just snow into northern Indiana, southern Wisconsin and northern Illinois.

By Wednesday at 5pm, freezing rain and ice (in the red) along with snow, will be possible in northern Indiana.

By Wednesday at 7pm, better chances of freezing rain move into northern Indiana.