Weekend Update: Winter Storm Warnings

New this morning, Winter Storm Warnings are now in place for the entire Stateline. For our western counties; including Jo Daviess, Stephenson, Carroll, and Whiteside, the warning will go into effect at 6pm tonight and will expire 12pm Saturday. In southern Wisconsin this time frame is the same. In Winnebago, Boone, McHenry, Ogle, Lee, and DeKalb counties the warning will go into effect at 6pm and will continue through 3pm Saturday afternoon.

TIMING: The timing of the system and snow fall arrival is still on track. Snow will develop to the west in Iowa in the mid- afternoon and will track across the Mississippi around 5-6pm tonight, but it will begin as a rain/snow mixture. It will move closer to the Rockford area around 7-8pm tonight. After 8pm we will see the mixture switch over to all snow, and the snow will continue to fall overnight. The heaviest of the snow will fall, with the highest accumulations, around midnight and will continue through about 6am Saturday morning. While the heaviest snow will be ending Saturday morning, moderate to light snow will continue into the early afternoon. The snow will taper off from the west to the east in the afternoon on Saturday.


 TOTALS: The totals of this system look to be very significant, with a lot if ingredients coming together with this system. With the current track of the low pressure system, as well as the position of the strong jet stream above, northern Illinois and southern Wisconsin look to be in a very favorable position for heavy snow. Narrow, heavy bands of snow will also be in place across the area leading to locally high amounts.
Generally, expect anywhere between 4-8 inches of snow, and it is likely that we will favor the heavier side of this. It is also possible where these narrow, heavy bands set up, that we could see highers totals near 9" to 11".

Anyway you break  this down, we will see a significant amount of snowfall.




STORM IMPACTS: Breaking down the impacts of the storm. Our Weatherisk will be Moderate at the onset of any precipitation. The ground temperatures are still very warm, so at first there will be minimal accumulations. This time frame is between about 5pm and 9pm.
The Weatherisk will switch to High overnight. The heaviest snow will likely fall between midnight and 6am, with the greatest accumulations at this time. The snow will start to taper off from west to the east in the late morning and into the afternoon. With heavy snow falling, visibility will be lower overnight and into Saturday morning. Roads will become snow covered as well overnight and Saturday morning.