Mountain wave clouds as viewed in Warrenton, Va. on December 27 from the FAA Command Center on top left. Satellite image at the same time shown bottom right. (Brandon Smith/NOAA)

As strong westerly winds (gusting over 40 mph in spots) roared over the Appalachian and Blue Ridge mountains Thursday in the wake of the Boxing Day storm, wave-like cloud formations developed in lengthy streaks over the Mid-Atlantic.

Wikipedia provides a nice description of how these clouds form:

The atmospheric internal waves that form wave clouds are created as stable air flows over a raised land feature such as a mountain range, and can form either directly above or in the lee of the feature. As an air mass travels through the wave, it undergoes repeated uplift and descent. If there is enough moisture in the atmosphere, clouds will form at the cooled crests of these waves

Wave clouds photographed in Fauquier county on December 27, 2012. ( Joe Westner via Facebook )

The presence of these clouds is a good indicator atmospheric turbulence which can affect air travel. But yesterday, reported aviation issues were few says the CIMSS Satellite Blog:

While there were isolated pilot reports of light to moderate turbulence across the region throught the day ..., there was one incident of severe turbulence encountered in Maryland at 18:49 UTC or 1:49 PM local time

Satellite image showing wave clouds over Mid-Atlantic at 1:45 p.m. Thursday, December 27, 2012 (NOAA Environmental Visualization Laboratory)

Related links:

Mountain waves across the Mid-Atlantic region of the US (CIMSS Satellite Blog)
NOAA visualization lab image of mountain wave clouds from 12/27/2012
Mountain Wave Clouds (Brad Panovich)