The climate of Virginia, a state on the east coast of the United States, is mild compared to more northern areas of the United States such as New England and the Midwest. Most of Virginia east of the Blue Ridge mountains, the southern part of the Shenandoah Valley, and the Roanoke Valley, has a humid subtropical climate (Köppen climate classification Cfa). In the mountainous areas west of the Blue Ridge, the climate is warm-summer humid continental (Köppen Dfb) or oceanic climate (Köppen Cfb).[1][2] Severe weather, in the form of tornadoes, tropical cyclones, and winter storms, impacts the state on a regular basis. Central Virginia received significant snowfall of 20 inches in December 2009.