By Ben Mutzabaugh, USA TODAY
A winter storm moving into the Midwest threatens to sock major airports in the region, possibly getting the week off to a slow start for air travelers.
Adding to the ominous news: East Coast delays are likely for Tuesday.
Rain and low clouds are forecast for Chicago this afternoon, conditions that typically bring delays to the city's busy O'Hare International Airport.
FLIGHT TRACKER: See if your flight is on time
AIRPORT DELAYS MAP: Real-time status updates
As of 3:55 p.m. ET, delays averaging more than two hours were hampering flights at O'Hare because of low clouds and poor weather, according to the Federal Aviation Administration's website.
Conditions in Chicago are expected to deteriorate throughout the day, with rain giving way to ice and snow by mid-afternoon, and as much as 8 inches of accumulation forecast through Tuesday morning.
If that proves accurate, long delays and cancellations are likely throughout the evening and into Tuesday morning at O'Hare. Both American and United each operate large hubs there.
The weather also could create backups at the city's other commercial airport – Midway – where Southwest is the biggest carrier.
Chicago problems could affect fliers throughout the USA. O'Hare is one of the nation's busiest hubs for connections, and weather problems there could complicate the itineraries of any passengers scheduled to connect there this afternoon or on Tuesday.
Additionally, even fliers traveling between cities under sunny skies could be affected. A flight from Los Angeles to Austin, for example, could be delayed or canceled if the aircraft scheduled to fly that flight gets stuck in Chicago.
By Tuesday morning, the wintry weather is also expected at a number of other smaller airports in the Great Lakes region later today, including places like South Bend, Ind., and Toledo, Ohio.
The nature of weather delays at those types of airports, however, are often more sporadic since lighter schedules give those facilities more of a buffer in managing operational slowdowns. Still, flights to hubs like Chicago remain at high risk of delays or cancellations.
The storm is forecast to move East by tonight and into Tuesday, bringing wintry conditions – and possible delays – to hub airports like Detroit and Cleveland.
By early Tuesday morning, things will likely go downhill in New York City and Philadelphia. No wintry weather is forecast, but wind, heavy rain and low clouds are expected – conditions that often bring lengthy delays to New York LaGuardia, Newark Liberty and Philadelphia airports.
As with Chicago, the impact of widespread delays at those three airports could quickly ripple nationwide. Newark, for example, is a major hub for Continental while US Airways operates one of its largest hubs at Philadelphia.
Elsewhere in the Northeast, wintry weather is also expected at a number of other airports in the eastern portion of the Great Lakes region by Tuesday, including Buffalo and airports serving small cities in lower New York state and in northern Pennsylvania.
Conversation guidelines: USA TODAY welcomes your thoughts, stories and information related to this article. Please stay on topic and be respectful of others. Keep the conversation appropriate for interested readers across the map.