A complex weather setup for central Indiana. We know that there will be areas of sleet/freezing rain moving in to central Indiana through the evening. There remains some question as to how far north it will get and how quickly it will get there.
A Freezing Rain Advisory will be in effect from 7 p.m. Friday evening through 1 p.m. Sunday afternoon for all of central Indiana.
Freezing rain - mixed with sleet along the northern edge - has developed in southern Illinois and southwestern Indiana. A report of sleet has come in as close as Vincennes at 10:45am.
The band of moisture is mainly moving east, with a slight northeastward pull. It appears that areas of south-central Indiana could see a brief period of sleet before changing over to rain early this afternoon.
One of the challenges is determining if it will be just rain or freezing rain. All data suggests that temperatures should climb a few degrees above freezing in Bloomington and Columbus this afternoon. If computer models are off by two degrees, the freezing line may stay south of those communities and allow freezing rain to develop. However, if the data/forecast is correct, temperatures should go above freezing for several hours this afternoon and evening, allowing just rain to fall.
As you go further north to Indianapolis, it appears it will take a little while longer for the moisture to arrive. Thinking has been that rain won't begin to fall until early evening (after 7 p.m.). However, there is some data that suggests rain could make it as far north as the Marion/Johnson county line by late afternoon.
It will be a close call as to whether or not sleet and/or freezing rain arrives in the Indianapolis metro for the evening rush hour. There will be a better chance for freezing rain in the Indianapolis area after 8 p.m.
Scattered showers, causing freezing rain, will be possible through the overnight.
By Saturday morning, there may be a thin glazing of ice on elevated surfaces, sidewalks, driveways and other untreated surfaces.
Computer models have been trending lower with how much freezing rain/ice we could see.
The graph above shows various computer models and their ice accumulation projections through Sunday morning. At this point, it looks like Indianapolis will likely see less than a tenth of an inch by late Saturday morning.
However, keep in mind that even 0.01" of ice can cause big problems on area roads.