UPDATED 02/01/11 10:43 a.m.

CHICAGO (CBS) — The worst of the blizzard is yet to come, but already, airlines have canceled more than 1,200 flights at O’Hare and Midway international airports.

Airlines at O’Hare have preemptively canceled over 1,100 flights while airlines at Midway have preemptively canceled over 100 flights so far, according to a release from Department of Aviation spokeswoman Karen Pride.

Delays averaging 45 minutes for both arrivals and departures were reported at O’Hare as of 10:30 a.m. No delays were reported at Midway.

Travelers are advised to check their airline’s website for flight statuses before leaving home, and arrive at the airport at least two hours before flight time, the release said.

At the airports, officials are working around the clock to keep planes flying as long as they can.

Outside, snow plows and bulldozers have been crisscrossing the runways trying to keep them clear for incoming and outgoing flights. Inside, passengers have been waiting it out, even though some flights have already been canceled as a preemptive strike against lunacy.

Southwest Airlines has already canceled all its flights to and from Midway from 3 p.m. Tuesday through Wednesday morning. Southwest says will resume service when the runways, taxiways and other airport services allow it to get going.

At O’Hare, United and American are issuing travel waivers to their customers, allowing them to change their flights without paying any fees.

The Sun-Times Media Wire contributed to this report.

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