New National Weather Service Director Louis Uccellini suggests that global warming causes snowstorms

Weather Service chief: We face 'new normal' of extremes

The onslaught of wild weather that has battered the USA in recent years - from Hurricane Sandy and deadly tornado outbreaks to extremes of drought and floods -- looks to be part of a "new normal" for weather patterns in the U.S., new National Weather Service Director Louis Uccellini said Wednesday.
...Uccellini cautioned that he doesn't think there are enough cases of extreme weather yet to prove the hypothesis.
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The extreme weather, surprisingly, may even include winter storms, such as the ones that have hammered the Northeast Coast this winter.

"We have observed more snowstorms and heavy rain events that have been extreme," he said, due to the fact that a warming atmosphere can "hold more water vapor that can increase the intensity of storms."
...The science of attributing extreme weather to climate change "is in its infancy, very difficult, and perhaps even the wrong question to address," said meteorologist Ryan Maue of private forecasting firm WeatherBell Analytics.