Winter Storm Janus, teaming up with another polar vortex, arrived in the eastern United States on Tuesday morning and is already causing travel problems across a large region. 

Here are some things you should know if you're traveling today and Wednesday. 

US Airways has issued a travel advisory for a wide range of cities, including Hartford, Washington, D.C., Baltimore, New York, Boston, Philadelphia, Providence and Richmond. In many cases, for those scheduled to travel today or Wednesday, US Airways is waiving change fees. See full details here.

Some afternoon and evening flights have already been cancelled at Philadelphia International Airport, Baltimore-Washington International Marshall Airport, Dulles International Airport and Reagan National Airport.

According to AccuWeather's Kristina Pydynowski, "snow was reaching the mid-Atlantic coast during Tuesday midday and afternoon, and will then turn northeastward toward southeastern New England Tuesday evening." AccuWeather added that this could be the biggest snowfall for Washington, D.C., since January 2011.

Adding to the problems will be some bone-chilling cold. Wind chills are expected to be well below zero across much of the Northeast tonight.

Here are some links to how the weather is affecting travel and life in various cities: