The snowstorm is winding down after dropping more than a foot of snow in many areas from the city north and near the lake to 5-10 inches in southern sections.
Some storm totals
With bursts of heavy snow that lasted for hours Tuesday evening, O’Hare airport officially recorded 12.6 inches of snow on Tuesday, with snow still occurring as Wednesday began. This is the biggest snowstorm, at O’Hare since last year when 12.0 inches fell in a 2-day storm on January 9-10 2009. Much of the snow came during the evening hours when snow was falling at the rate of about about one inch per hour. Through 7 pm O’Hare had logged only 5.1 inches of snow.
Snow, which had fallen steadily much of the day at little more than a moderate clip, suddenly intensified late Tuesday. What had been a fairly innocuous late winter snow across the Chicago area through mid-afternoon suddenly took on the trappings of the significant winter storm which had been predicted–particularly in the counties lining Lake Michigan’s Wisconsin and Illinois shorelines. Thoroughfares on which road chemicals had worked so well much of the day, quickly covered with snow, rendering them treacherous as night fell.
By late evening, Lake County’s Antioch, just south of the Wisconsin line, sat under a fresh 14-inch snowpack while just to the south in Round Lake Heights, a 12-inch snow glistened beneath streetlights, which dimmed as each wave of heavy snow passed. Other snow totals in Mount Prospect (11.3 inches), Buffalo Grove (11.0) and Mundelein (10.5) moved within striking distance of a foot—and totals of 9.6 inches at Beach Park, 9.4 at Oak Brook, 8.3 at Downers Grove as well as the official in-city totals of 8.3 at O’Hare and 7.0 at Midway–seemed likely to surge still higher overnight as late evening snows grew in areal coverage and intensity. Weather radars from Chicago to Green Bay indicated clusters of heavy lake-effect snow were in the process of consolidating into an elongated 260-mile band—extending from east of Door County, Wisconsin south the length of Lake Michigan into northeast Illinois. The feature, referred to by meteorologists as a “lake-snow plume,” threatened additional accumulations of snow up and down the western shore of the lake during the night.
Lake snow plumes form as low-level winds converge over warmer lake waters. These converging winds lead to a pile-up of air at the surface which has little option but to rise, cooling and becoming saturated as the lake moisture evaporated in it condenses. Towering clouds form from which locally intense snows fall. With winds guiding these lake-effect clouds southward over lake waters for an extended distance, the chance for moisture to accumulate is huge. The snows which fall at the end of such a long plume of saturated air can be quite formidable—as northwest Indiana residents are to find out much of Wednesday as these lake snows slowly shift east.
Wednesday is to open with the heavy snows of the plume riding into northwest Indiana’s Lake and Porter Counties—but shifting gradually eastward to La Porte County by late in the day.
Third consecutive snow season to top historic norms
Tuesday’s 8.3-inch snowfall at O’Hare pushes the site’s seasonal snow tally to 40.5 inches—well above the 38 inches of snow considered “normal” in a full season. It’s the third consecutive Chicago snow season to exceed the normal full-season tally.
Boston and New York missed last weekend’s big snow—but not this one
Washington, Baltimore and Philadelphia were all buried by record-breaking snows last weekend which by-passed Boston and New York. That won’t happen with the current storm. Heavy snows and howling winds are predicted in both cities Wednesday.
It was snowing at the rate of more than one inch an hour at Antioch this evening as they racked up 4.5 inches of snow between 6 and 10 pm bringing the storm total there to 14 inches.
More late snow totals
Oak Brook 9.4 inches
O’Hare (official) 8.3 inches
Chicago- Dan Ryan and 95th Street 8.8 inches
Romeoville 6.6 inches
Oak Park 8.0 inches
Morton Grove 9.5 inches
Midway Airport 7.0 inches