The INDOT map for Sunday, which showed the transition from rain to snow over the state in the early AM hours, was very accurate. Snow was ending from north to south over the northern and central parts of the state, with the most snow occurring in the central and southern parts of the state. However, the forecast only called for a couple inches of snow from this. However, very high (negative) values of omega along the front contributed to strong forcing and lift along the front, which allowed for a heavy band of snow to occur over parts of central Indiana, including Crawfordsville. Some 8" amounts were found there...which was much higher than forecasted. Timing was forecasted well overall, but the convective nature of the snow band along the front was not interpreted correctly.
You can notice the snow streaks on the visible satellite which indicates the narrow but heavy snowfall accumulations that happened Saturday night.
The above map shows the 18Z GFS forecast model with a high pressure centered just off to our west. There is an area of heavy precipitation that will be moving off of the east coast over the next few hours.
The above image is from 1740Z showing current surface observations. Indiana is generally seeing clear skies with light winds and temperatures in the high teens. These temperatures are expected to rise some over the next few hours until sunset.
Clouds will be on the increase as we have this new weather system that will be sweeping through from the southwest.
Verifying Past Runs:
Found at NOAA: http://water.weather.gov/precip/index.php
The two following are to verify the predicted precipitation amounts comparing NAM and GFS. The NAM was closer but underestimated the span north, while the GFS overestimated in areas. If this is any indication on the precipitation amounts for Tuesday's storm it could fall somewhere between the GFS and NAM.