Winter Storm Update

The Climate Prediction Center issues a threat assessment every day. As you can see by the map to the left, there is a threat of heavy snow Sunday into Monday for much of Northern Illinois. As I've mentioned in past blog posts, the amount of moisture available is critical...in addition to the track of the low.

Models haven't deviated much over the past 24 hours. We're still on target to receive nearly as much snow as December 1st, however over a longer duration. This snow will begin late Saturday night and continue through the mid-morning on Monday.

I'm not making an official forecast on the air (for snowfall accumulations) until Friday, but it appears that three inches seems certain with lower probabilities the higher we go. There could be some areas that surpass 8 or 9 inches, depending on the exact track.

To the left is the afternoon GFS model. I figure since I posted it for the past few days I should keep the string going and give you today's, right? A few things! First, the center of the low has moved east. That would bring the heavier snow moves east. However, the "540" line is closer to us. That is often-times where the rain/snow line sets up. I don't think there's any reason to change the going forecast. I may post some forecast accumulations here on the blog after the 10pm news (once the 6pm models are in). -ERIC