Climate Change and Snow


What affect could a warmer climate have on Snowfall - A few of my thoughts.

If you live in the southern U. S., odds are, but no guarantee, that a warmer climate will cost you some of your snowfall. The southern half of the country, outside of higher elevations, is already rarely cold enough to support snow.

The northern half of the U.S. is cold enough such that a warmer climate is not guaranteed to reduce snowfall much below the current climat normals.

Warmer Atlantic Ocean sea surface temperatures could reduce snowfall in near-coastal sections of New England. Cold air is not a problem for New England in most winters. Coastal storms however frequently pull warmer air inland to change snow to rain. Warmer ocean temperatures could result in even faster changeovers penetrating further inland.

The Great Lakes region is tricky. A warmer climate means warmer lake temperatures and less ice cover from late autumn to early spring. Both conditions result in more lake-effect snow assuming strong enough cold air outbreaks over the lakes. What can happen is that the average onset of lake-effect snow is delayed but the season continues through the entire winter. The southern edge of the Great Lakes, such as South Bend, IN and Cleveland, OH could experience enough warming to inhibit snow accumulations. Regions farther south that get moisture off the Great Lakes, such as the mountains and plateaus of eastern Kentucky, eastern Tennessee, western Virginia, and western North Carolina would be even more prone to a reduction of snowfall.

The big question is how climate warming would weather patterns. If the middle to upper tropospheric winds become more zonal then the likely result is weaker storms, weaker cold air outbreaks, and less northward transport of moisture from the Gulf of Mexico. A more wavy flow means stronger storms, more frequent storms, better moisture transport, and stronger intrusions of cold air further south.