Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
912 PM CST Sat Jan 22 2022
.UPDATE...
Issued at 912 PM CST Sat Jan 22 2022
Based on upstream radar trends and the incoming 00Z CAM guidance,
we shifted the axis of heaviest snow north by a county. In
addition, we lowered snow ratios a hair given a modest warm nose
sampled by the 00Z DVN RAOB which places much of the low-level
temperature profile just outside the DGZ (new ratios are more like
15:1 to 17:1 instead of 20:1). The updated forecast now features
the swath of 3-5" of snow from the heart of Rockford to Chicago,
2-4" from Dixon to Joliet to Wheatfield, and 1-3" from Mendota to
Rensselaer. It`s possible we`re still too far south...but at least
we seem to be heading in the right direction.
Even with a shift in the axis of snow, impacts should remain
similar with snow-covered roads within the Winter Weather Advisory
area. Regardless, keep in mind actual amounts on the southern
side (e.g. La Salle, Grundy, Kankakee, Newton, and Jasper
counties) will end up on the lower-end of our snowfall forecast