In addition to what is expected to be a wet heavy snow, easterly winds are forecast to gust between 30 to 35 miles per hour, creating significant visibility restrictions and shallow drifting when combined with the falling snow. Isolated higher amounts may happen, depending on how long the heaviest bands of snow stay over any given area. After sunset, temperatures will fall back down well below freezing.
The updated forecast is a significant change from the warnings provided Thursday, when the NWS said that Howard County could see anywhere from 3 to 8 inches of snow late Friday night through Saturday evening. The transition from rain to snow will take longer for areas south of a line from Cedar Rapids to the Quad Cities.
Dry easterly winds over southern Wisconsin will block the eastward edge of the snow, resulting in a very sharp cut-off from west to east over southwestern and southern Wisconsin.
There isn't a possibility for meaningful snow in Northern Virginia or Tidewater, and the chance of accumulation is even minimal in central Virginia.
Rainfall amounts of a half-inch to one inch are possible, and may be higher. In the Ohio Valley and central Appalachians, snow will fall mainly during the day.
This is the first Winter Storm Warning for Indianapolis in two years.
Expect steady snow showers, at times mixing with sleet.