English: The first week of January 2016 brought a shift in the weather for much of the central and eastern United States. Despite being near-record warm during the closing days of 2015, snow and frigid temperatures moved in on the opening days of January. Temperatures dropped dramatically in many areas, such as Annapolis, Maryland, where Christmas Eve-celebrants toasted in 73˚F (22.8˚C) temperatures on December 24 but shivered on January 5 with highs of only 33˚ F (0.5˚C) - a 40 degree F drop.

Sudden snaps of cold air and high wind chills not only leave residents shivering, but they also make waves in the atmosphere - literally make waves - as seen in this true-color image captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Aqua satellite on January 5, 2016.

In this image, snow glazes the ground of southern Canada and the northeastern United States, with a dusting also along the ridges of the Appalachian Mountains. Off the coast of New England, parallel rows of clouds line up from north to south along the direction of the prevailing wind.

When strong wind emerging from a cold surface blows over the warmer, moister atmosphere over the open ocean, cylinders of spinning air may develop in very regular, linear patterns. Clouds form along the upward cycle in the cylinders, where the air is rising, while skies remain relatively clear along the downward cycle, where air is falling. The result is a remarkably regular striped pattern of parallel lines in the clouds.