The Historic Chicago Blizzard of 2011

On Tuesday, February 1, 2011 lasting through the morning of Wednesday, February 2, 2011, Chicago experienced a historic blizzard with severity that is seen on average once every 20 years. This particular storm had a magnitude comparable to the blizzard of January 26-27, 1967. Over the course of 35 hours on January 26-27, 1967, 23 inches of snow fell on Chicago. As of 10:30 a.m. on Wednesday, February 2, 2011, 20.2 inches of snow was recorded at O’Hare International Airport and 20.9 inches at Midway International Airport, putting the storm ahead of the infamous blizzard of January 1979 that left 18.8 inches. The Chicago Blizzard of 2011 has become the 3rd biggest on record with later reports that could confirm it to be in 2nd place. Snow fell for a total of 22 hours. This blizzard produced snowfall rates of 2-3 inches per hour at times with wind gusts exceeding well over 50 mph. Wind gusts hit 70 mph at the lakefront. Spectacular lightning followed by significant rumbles of thunder occurred with this storm. As reported by Chief Meteorologist from WGN-TV 9 Weather Center, Tom Skilling and Frank Wachowski from Midway.

The first few seconds into the film appears the surface analysis on Tuesday, February 1, 2011. Note the boundary of high pressure off to the North and a low pressure track below progressing from southwest to northeast. A typical setup for blizzards. With the pressure difference between the boundaries creates a pressure gradient where high speed winds form. This particular case has been enhanced by a “coupled” jet stream where the polar jet is swooping down in the familiar horseshoe-shaped pattern. The sub-tropical jet is coupling with this system hence the shape and severity of the storm. Also with this setup, an outbreak of tornadoes occurred in the southern states (note the area of low pressure with the warm front leading ahead of the cold front). Warm air was pushed high into the atmosphere in this area creating the conditions for tornadoes. A visual satellite image from NOAA displays the entire storm system as it appeared on Tuesday, February 1, 2011. About 5 seconds into the actual film of the storm, lightning occurs followed by a significant rumble of thunder. Thundersnow, in this case, was associated with a heavy synoptic system with strong vertical mixing which allows for favorable conditions for lightning and thunder to occur.

Blizzard 2011: A Long Ride Home

Uploaded by wttwchicago on Feb 3, 2011