Update 2:45 p.m.: Look outside. It appears the storm that meteorologists have been talking about since the weekend has arrived.
It seems that warnings of a massive blizzard have been heard and heeded.
All over Chicagoland, grocery stores are seeing longer lines than normal. Hardware stores are selling massive amounts of salt. Hospitals are putting staff members up in hotels. And many children -- and their parents -- are waiting for word on school closings.
"The message we want to send is 'Be prepared,'" said NBC Chicago meteorologist Brant Miller.
With talk that the storm on Tuesday and Wednesday could rank among the biggest since records were kept in Chicago, city officials say they're preparing for the worst.
"If we get the amount of snow that some are predicting, it will be the largest snowstorm in Chicago since 1967. This means very large amounts of snow, falling temperatures and high winds, especially around the lakefront," said Mayor Richard Daley's Chief of Staff, Raymond Orozco.
The city's 274 snow-fighting trucks, as well as 120 garbage trucks armed with plows, will be out working to clear arterial streets.
The Chicago Transit Authority said it will operate regular weekday schedule throughout the storm but is prepared to provide early rush hour service on Tuesday for those attempting to head home from work early.
On those rail lines that don’t operate 24 hours, such as the Green, Orange, Brown, Pink, Purple and Yellow lines, the CTA will dispatch additional sleet trains to keep snow from building up on the tracks and the third rail from icing over.
The fire department has suspended training and will increase the alarm of every call to increase preparedness. Other fire crews will be on the streets digging out hydrants.
The National Weather Service has issued a blizzard warning for the Chicago area beginning at 3 p.m. Tuesday and lasting until 3 p.m. Wednesday.
Current estimated snow totals hover between 18 inches and two feet.
The NWS alert came with a stern warning: do not travel.
Already, dozens of schools, businesses, day care centers and organizations have announced closures or delays.
At O'Hare and Midway airports, more than 1,000 flights have been cancelled. It should go without saying that travelers should call ahead or check with their airline online.
In advance of the storm, United Airlines waived its fee to change or reschedule flights in 19 states during through Wednesday.
Several downtown hotels are offering "snow bird" specials for commuters who don't want to attempt traveling home.
As if the snow weren't enough, powerful northerly winds will blow through the area, causing drifting snow with blizzard conditions and temperatures as low as 10 below zero on Wednesday.
The 10 worst snowstorms in Chicago history, according to the National Weather Service:
23.0 inches Jan 26-27, 1967
21.6 inches Jan 1-3, 1999
19.2 inches Mar 25-26, 1930
18.8 inches Jan 13-14, 1979
16.2 inches Mar 7-8, 1931
15.0 inches Dec 17-20, 1929
14.9 inches Jan 30, 1939
14.9 inches Jan 6-7, 1918
14.3 inches Mar 25-26, 1970
14.0 inches Jan 18-20, 1886
Ready.gov: Winter Weather Preparedness