Snowfall Forecast: Periods of snow through Tuesday morning

Weather Blog

Update: Snowfall amounts have been increased region wide due to a northward shift in storm track and the storm looking stronger.

Peoria, Ill. (WMBD) – Another storm system will bring periods of light to moderate snow to Central Illinois through Tuesday. Like our previous snows over the past week, this snow will be dry and fluffy which will lead to hazardous travel, especially with breezy winds expected.

Storm Impacts

  • Periods of snow Sunday Afternoon through Tuesday morning
  • Heaviest snow expected Monday afternoon and Monday night
  • Several inches of snow possible
  • Winds of 10-20 mph will lead to areas of blowing and drifting snow

The heaviest snow from this system is expected to remain south and east of the region, but models have trended further north and stronger with the storm. The end result is that Central Illinois will experience more significant snowfall and impacts from the incoming storm system. The National Weather Service has issued Winter Weather Advisories for all of Central Illinois through noon Tuesday.

Storm Timing

This will be a long duration event but with the snow coming in two separate waves. The first wave has started to impact Central Illinois and will continue to bring light snow to the region through Monday morning. We’ll see a break in the snow before the main system moves in after 3 pm Monday.

Moderate to heavy snow will spread across Central Illinois during the Monday evening commute making travel difficult. The snow is expected to continue Monday night with light snow showers and flurries remaining possible through Tuesday morning. In the end, several inches of snow are expected through noon Tuesday.

Winds will also be blowing from the north at 10-20mph with gust up to 30 mph possible. With dry and fluffy snow expected blowing and drifting snow is likely making for hazardous travel conditions.

Snowfall Forecast

Snow accumulations will be highest east of the Illinois River where widespread accumulations of 4-8 inches look likely. Snowfall amounts will start to taper off to the west with 3-6 inches along the Illinois River and 2-4 inches west of a Peru to Macomb line.

Even though the heaviest precipitation is expected across southern Illinois and Indiana, high snow ratios across Central Illinois could lead to higher amounts locally.

So what is the snow ratio?

You’ve probably heard of the old rule of thumb that 10 inches of snow equals 1 inch of water (10:1). In reality the snow ratio varies from location to location and from one event to another and often change during events. During our last round of snow on Saturday, Central Illinois had snow ratios of 30:1!

For this upcoming event Peoria is expected to experience a snow ratio between 20:1 and 25:1 with 0.15″ to 0.25″ of moisture. This means that Peoria could see anywhere from 2.0″ to 5.0″ of snow, you can see the math below.

20:1 Ratio with 0.15″ of water
20″ x 0.15″ = 3.0″ of snow

25:1 Ratio with 0.15″ of water
25″ x 0.15″ = 3.75″ (Rounded up to 3.8″) of snow

With only 0.15″ of moisture, Peoria would see 3-4 inches of snow

20:1 Ratio with 0.25″ of water
20″ x 0.25″ = 5.0″ of snow

25:1 Ratio with 0.25″ of water
25″ x 0.25″ = 6.25″ (Rounded up to 6.3″) of snow

With about 0.25″ of moisture, Peoria would see snow totals as high as 5-6.5 inches

With the high snow ratios in place, it wont take much additional moisture to drive totals up more.

The Dangerous Cold Continues

Wind Chill Warnings and Advisories remain in effect across Central Illinois through Monday morning. Central Illinois has been experiencing wind chills between -15° and -30° since Saturday evening and it is expected to continue through Monday morning. The coldest wind chills will be west of the Illinois River.

Be sure to limit your time outdoors, and when you do venture out, cover up as much exposed skin as possible and dress for being outdoors longer than you plan to be. Click here for more great cold weather safety tips.

Copyright 2021 Nexstar Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Latest Local News

More Local News