**A Winter Storm Warning is in effect for the entire Chicago metro area including all of southern Wisconsin and NW Indiana from 3am CST Tuesday to midnight CST Tuesday night**
A major late season winter storm is set to unfold across the region late tonight through Tuesday night. The center of two storm systems, which are to consolidate as they approach the region Tuesday, are still hundreds of miles away to our west over the Plains. However, the moisture field associated with these two storms is large, and the coming together of these two storm systems will make for a dynamic winter storm. Below are some key points regarding the winter storm:
Snow Timing: Snow will overspread the region from west to east overnight tonight into Tuesday morning between 3-5am CST.
Heaviest snow timing: Heaviest snow will occur from around 10am CST to 9pm CST Tuesday. The best chance for thundersnow and snowfall rates of 1 to 2 inches per hour will be during this timeframe.
Snow amount probabilities:
- Widespread snow of 1" or more: 100% (high)
- Widespread snow of 4" of more: 90% (high)
- Widespread snow of 6" or more: 75% (high)
- Widespread snow of 8" or more: 55% (moderate)
- Widespread snow of 10" or more: 45% (low to moderate)
- Widespread snow of 12" or more: 25% (low)
Snow Forecast: After looking at a suite of models today, am more confident that scenario #2 from my previous post will pan out with the heaviest snow axis knifing from southern Wisconsin and north-central Illinois right through the heart of Chicago and into northern Indiana. Short range forecast ensembles also suggest that a zone of max snow production and growth above the surface will be present over the region during the day on Tuesday. With that said, it is safe to say that there will be widespread snow accumulations on the order of 5-10 inches with locally higher amounts. Due to expected lake enhancement, the best chance for the higher snow totals will occur near the lake. Higher amounts will range from 9-13". With the amount of moisture associated with this storm, would not be surprised to see double digit totals and totals that top a foot.
Winds: In addition to the heavy snowfall will be the gusty northeast winds. Winds are forecast to gust 30-35 mph at times which could cause for blowing and drifting snow.
Bottom line: This will be a high impact storm with significant travel delays (air & ground) and possible power outages. Both the morning and evening commute will be impacted with the evening commute bearing the brunt. Everyone is strongly advised to keep up with the latest weather forecast/updates and plan accordingly for the likelihood of significant snowfall and potential impacts Monday night through Tuesday night. Stay tuned for more updates!
Prepared by Meteorologist Andrei Evbuoma on
Saturday, March 3, 2013 at 5:00 P.M. CST
Copyright © 2013 by Andrei Evbuoma
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