When its snowing/snow blanketing the ground and you have an earthquake at the same time. This is how the snowquake is born.
In 2013, on December 7th, the state of Oklahoma was rocked by an earthquake of a 4.8 magnitude that was centered close to Edmond, Oklahoma. During this time most of Oklahoma was covered in snow due to recent snowstorms. The snowquake was felt from the Tulsa area to the Enid area down through the Edmond area, OKC area, and the Norman area.
by Twilightseven December 08, 2013