A deep upper level trough over the west will shift into the plains Saturday night then across the upper Midwest Sunday and Sunday night. A surface low will swing out of the southwest into northern Missouri then into north central Illinois Sunday evening. Our first round of snow will move through the state late Saturday night, mainly after midnight in western Iowa. The bulk of the precipitation will be during the day on Sunday, and this will generally be light to moderate snowfall with periods of moderate snowfall Sunday afternoon.
Preliminary thoughts are that there will be a general 2”-5” inches of snow accumulation across the state by Monday morning. The highest amounts will occur in Central and western Iowa. This is where 3”-4” of snow will be common with locally 5” amounts across northwest Iowa. This snow will be very light and fluffy due to the cold temperatures. Frozen to liquid precipitation ratios will be between 15:1 to 25:1 so it will not take much moisture to get measureable snow. This ratio means for every one inch of liquid precipitation, we would see 15 to 25 inches of snow. Right now it is uncertain if the National Weather Service will issue any watches or advisories but we will continue to monitor this, and if any do become issued, we will post the very latest on our Facebook page.
The snow may have an impact on the Monday morning drive as winds will be breezy causing blowing and drifting snow. This will reduce visibilities and cause hazardous driving conditions. If you have to be out on the roads Monday, make sure to plan ahead and allow yourself extra time. After this system departs on Monday, another blast of cold air will come in late Monday into early on Tuesday. This event is still 48 hours away, and its exact track and timing will likely change a bit in the coming hours. Nevertheless, there is enough agreement in the model guidance to start to pinpoint down where the heaviest snowfall accumulations will be. We will continue to track this system over the next 48 hours and will bring you the very latest on our Facebook page and right here at Iowachase.com.