Snow cover vs. snow depth: Looking at the data, we’re doing just fine on both counts

Currently, Chicago has the fourth-largest peak snow depth on record during a winter season here, according to Jake Petr, a meteorologist with the National Weather Service’s Chicago office. Snow depth measures the combined total depth of both old and new snow on the ground. The 21 inches on the ground Tuesday at O’Hare International Airport, the city’s official recording site, ties the peak snow depth of the 2010-11 winter season.