Tonight's snowfall will be location dependent as some areas will see half of a foot of snow or more, and others will see less than one inch.
Before we get to snow, expect precipitation to begin as rain later this afternoon and evening. We will start to see a changeover to snow from west to east as we head into tonight, mainly between 8 PM and 12 AM.
However, not everyone will change over to snow during this time. Temperatures for some areas just south of I-74, both at the surface and up to a mile above the surface, will stay around or just above freezing. This will allow for rain to continue in these areas.
However, locations that will see snow develop by the early morning hours tomorrow will likely see heavy snow falling. Snowfall rates my be as high as 1-1.5" per hour.
As we get closer to sunrise tomorrow night, the heavy snow will come to an end, but more locations that initially saw rain will see a changeover to light/moderate snow.
Snow showers will taper off during the morning tomorrow, and then we'll see snow melt quickly within the next 24-36 hours.
Here is a look at how much snow I am expecting by tomorrow morning.
This snowfall map is a little busier than most that I put out, so let's break it down.
As I mentioned above, the highest snowfall totals will be for areas near and north of I-74. Overall, we can expect a widespread 4-8" of snow here. However, it will be possible for a few spots inside the black dotted line to see closer to 10"
Expect a sharp cutoff from significant to minimal totals near and south of I-74. Due to the sensitivity of precipitation type and temperatures - just a degree or two will mean the difference between rain and snow - it is impossible to pinpoint exactly where this cutoff will form. However, I expect it to be somewhere near or just south of I-74. I would expect it to be within 15-20 miles of a line from Canton to Bloomington.
Just a few miles change in the rain/snow will make a very large difference in snow totals for this area. So again while I can't pinpoint exactly right now, I do expect that wherever this line forms, we could go from 4-6" of snow to less than 1" in 25 miles or less.
Areas near and south of Route 136 will likely stay as rain for most of the rain, so snowfall totals there will be minimal. Depending on how late the changeover is to snow, some locations in white may not see any accumulation at all. However, if snow does fall and stick, I would expect no more than 1" in those areas.
Any snow that falls tonight will be heavy, wet snow. Locations that see higher snow amounts could see localized power outages as extra weight on tree branches and power lines could cause them to snap or break.
We'll continue to keep an eye on the latest and give you updates as snow begins to fall overnight. Get the latest forecasts on-air, on social media, and on our Heart of Illinois ABC App.