Winter storms

One of the most robust measures of Earth’s changing climate is that winter is warming more quickly than other seasons. The cascade of changes it brings, including ice storms and rain in regions that were once reliably below freezing, are symptoms of what I call “warming winter syndrome.” Wintertime warming represents the global accumulation of heat. During winter, direct heat from the Sun is weak, but storms and shifts in the jet stream bring warm air up from more southern latitudes into the northern U.S. and Canada. As global temperatures and the oceans warm, that stored heat has an influence on both temperature and precipitation. The U.S. has been feeling this warming in the winter of 2023-24, the warmest on record for the Lower 48 states. Snowfall has been below average in much of the country. On the Great Lakes, the ice cover has been at record lows. Late February saw a wave of summerlike temperatures spread up into the central and eastern U.S., along wi...

Texans like to think of their state as the energy capital of the world. But in mid-February 2021, the energy state ran short of energy. An intense winter weather outbreak, informally dubbed Winter Storm Uri by the Weather Channel, swept across the U.S., bringing snow, sleet, freezing rain and frigid temperatures. Texas was hit especially hard, with all 254 counties under a winter storm warning at the same time. Across the state, sustained arctic temperatures froze power plants and fuel supplies, while energy demand for home heating climbed to all-time highs. Cascading failures in the electric power and natural gas sectors left millions of people in the dark for days. At least 246 people died, possibly many more, and economic damage estimates damages reached US$130 billion. Water systems, which require energy for pumping and treatment, also were severely damaged. At least 10 million people were under boil-water notices during and after the storm, sometimes for weeks. Low-incom...

It’s hard for most people to imagine more than 4 feet of snow in one storm, but such extreme snowfall events happen along the eastern edges of the Great Lakes. The phenomenon is called “lake-effect snow.” It starts with cold, dry air from Canada. As the bitter cold air sweeps across the relatively warmer Great Lakes, it sucks up more and more moisture that falls as snow. Canadian winds pick up moisture over the Great Lakes, turning it into heavy snowfall on the far shore. NOAA I’m a climate scientist at UMass Amherst. In the Climate Dynamics course I teach, students often ask how cold, dry air can lead to heavy snowfall. Here’s how that happens. How dry air turns into snowstorms Lake-effect snow is strongly influenced by the differences between the amount of heat and moisture at the lake surface and in the air a few thousand feet above it. A big contrast creates con...