This is likely to happen now and could be one of the most major high impact snowstorms to hit the state in a while.
From the Morning Area Forecast Discussion of the Quad Cities NWS Office:
OVERVIEW…MINOR CHANGES TO CURRENT PACKAGE EXCEPT UPGRADED WNW 1/2 TO 2/3 ARE FOR BLIZZARD WATCH AS BLIZZARD CONDITIONS WILL OVERSPREAD AT LEAST ALL THIS REGION AFTER MIDNIGHT TUESDAY NIGHT AND THROUGH MOST TO ALL OF THE DAY WEDNESDAY. THUNDER-SNOW ALSO EVIDENT MOVING INTO AREA TUESDAY NIGHT OVER MOST OR ALL THE REGION.

SNOW EVENT AMOUNTS OF 6 TO 12 INCHES REMAIN ON TAP WITH LOCALLY HIGHER AMOUNTS OF 12+ INCHES…LOCALLY UP TO 15 INCHES SUGGESTED +/- 40 MILES OF A FREEPORT TO IOWA CITY TO OTTUMWA LINE. THIS SYSTEM REMAINS ON TRACK TO BE ONE OF THE MOST SIGNIFICANT HIGH IMPACT EVENTS IN THIS AREA FOR SEVERAL YEARS…IF NOT LONGER.

Because of this, the NWS in the Quad Cities has replaced their Winter Storm Watch with a Blizzard Watch effective at 6am Tuesday morning and in effect until 6pm Wednesday evening for the following counties, Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines, Dubuque, Henry, Iowa, Jackson, Jefferson, Johnson, Jones, Keokuk, Lee, Linn, Louisa, Muscatine, Scott, Van Buren and Washington. It also includes Clark and Scotland Counties in NE Missouri and Jo Daviess, Stephenson, Carroll and Rock Island Counties in Illinois. A Blizzard Watch remains in effect in NE Iowa as well. Warnings will likely be issued later today in the state. Already Winter Storm Warnings have been hoisted this morning in eastern Nebraska. This is a very DANGEROUS storm and should not be taken lightly.
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