Every so often, a dome of upper-level high pressure sits in place for a few days, sometimes as long as several weeks. A major block can produce seemingly endless stretches of blazing heat or bitter cold. By the time it dissipates, it may leave behind a whole stack of broken weather records and an array of disastrous consequences.

The MetEd online training service covers topics in meteorology, weather forecasting, and related geosciences. Users can delve into everything from satellite meteorology to tsunami preparedness and forecasting dust storms.