The air in the vicinity of Earth’s biggest urban areas includes a wild variety of constituents emitted by cars, factories, trees, and much more. Tracking the fate of such air as it spreads outward is no simple task.

A new study led by NCAR’s Wei Yu and CU-Boulder’s Weiqing Han looks at the effects of the Madden-Julian Oscillation (MJO), the largest source of intraseasonal (within one season) variability in the tropics, causing wet and dry periods to alternate.

How can a relatively small increase in the average temperature of the planet lead to numerous record-breaking heat waves? Part of the reason can be gleaned from a single graph.

An email exchange following Part I revealed the enthusiasm of the Boulder weather community for clouds and the presence of many instruments probing the atmosphere over Boulder—and, in the end, the height of the formation.

Millions of eyes were on the wedding of Prince William and Catherine Middleton even as another major UK news story took shape—one dealing with meteorology rather than monarchy.