The image below shows the GFS model forecast for Tuesday October 30, 2012. It shows the 850 mb heights, temperature, and wind. The 850 mb temperature over Indiana is in between the -3 and -6 degrees Celsius temperature countours. These are relatively cold 850 temperatures for this time of year for Indiana. The 0 and -3 degree Celsius contours also extend out to parts of Virginia, North Carolina, and South Carolina. The pressure gradient associated with the lower pressure system is very strong. The 850 winds over parts of PA are above 70 knots.
This web product was produced James Parish.