We’ve certainly witnessed lake-effect snow bands doing their thing in recent days. Their bursts of snowfall tend to be incredibly localized—rapidly whitening one area while completely avoiding others.
The limited real estate covered by the snows generated in “lake-effect” scenarios can be striking. But so can the amount of snow which is generated at times in amazingly small areas.
The selective nature of lake snows was on display for all to see in the Evanston, Skokie and Morton Grove areas Thursday evening. The fluffy, silver-dollar-sized snowflakes reported in that region of the metro area deposited comparatively quick 3 to 5” accumulations—even as the official O’Hare weather observation site, not more than 10-15 miles away, only picked up 0.3” of snow. Midway’s take of the lake-effect snow “pie” was even smaller, having measured a miniscule 0.2” accumulation.
High resolution computer models, which aid us in predicting lake snows, suggest concentrated clusters of snowfall will flirt with shoreline areas from eastern Wisconsin south into extreme northeast Illinois and parts of northwest Indiana from time to time Saturday. Converging winds, responsible for producing these snows, may set the stage for brief bursts of significant snowfall likely to be limited to highly localized areas. A quick dusting to as much as an inch or two may fall with some of the heavier snow showers while other sections of the Chicago area escape with just flurries.
Friday’s 0.3” of snow does little to boost lowest seasonal snow tally in 69 years; total of 0.7” just 8 per cent of normal!
Friday's fresh 0.3-inch accumulation of snow at O'Hare boosted Chicago’s official seasonal snow tally to 0.7”—just 8 per cent normal and nearly 8” off the typical full season tally by this date.
A 308th day at/above freezing ties a 134-year record for most consecutive daytime highs at/above 32 Saturday; record could fall Sunday
Evidence of this winter’s remarkably “un-wintry” ways continues to accumulate. We've covered the paltry snow situation. The failure of truly cold air to reach the area is yet another of the emerging stories in this very "un-wintry" winter of 2012-13 to date.
Saturday's predicted 33-degree high will mark the 308th consecutive day high temperatures have failed to remain below freezing. That's a development which will tie a 134-year-old record for the most back-to-back days with daytime temperatures at or above freezing. The failure of temperatures to fall short of 32-degrees Sunday would set a new record.
Overnight storm deposits fresh snow cover in already hard-hit areas of downstate Illinois and Indiana
The second storm in less than a week—and the Midwest’s third storm of the past two weeks—swept downstate Illinois and Indiana overnight depositing another 2 to 6” of snow.
NOAA reported Friday that 64.5% of the Lower 48 was under a cover of snow—the largest national snow-pack in nearly two years.
Last year’s unimpressive 29% snow coverage across the 48 contiguous U.S. states was just 39% of that tally.
Several forecast models hint at New Year’s Eve snow threat
It’s not a forecast yet carved in stone. But, several of our computer forecast models develop snow here late Monday and Monday night—suggesting a potentially snowy New Year’s Eve. That wouldn't be without precedent. One in four Chicago New Year's Eves have registered measurable snow.
Season’s coldest air to hit mid-week—but only for several days
Winter’s chilliest temps to date may put in an appearance next week. The arctic air would follow several frontal systems expected to sink into the Lower 48 in coming days. The good news is the overall pattern appears progressive, so the chill isn't likely to linger for long.