It’s not just Hudson Valley residents that are bracing for snow and treacherous driving conditions from today’s storm.

Tens of millions of people across the country from the Plains to the Northeast are under a winter weather watch, warning or advisory.

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MORE: Snow and sleet to make for treacherous evening commute

Warm, moist air from the Gulf of Mexico is combining with a cold system from the Rockies producing a wintry mix.

Among the areas expected to get hit especially hard are Washington, D.C. and Baltimore, where up to six inches of snow and sleet is expected to fall.

Other parts of the East Coast are also going to get pounded as a state of emergency has been declared for all of New Jersey's 21 counties.
Some of the spots not getting snow are getting buckets of rain. Flash flood watches are in effect from north Alabama all the way to West Virginia.

If you're flying today, you can expect to deal with delays and cancellations, due to the snow. Flight Aware says more than 1,600 flights have been canceled today, including dozens at LaGuardia and JFK.

Several arrivals and departures have had delays at Westchester County airport. If you plan to fly, check with your carrier before heading to the airport.