Freezing Temperatures: A blast of Arctic air can be dangerous, especially when combined with blustery winds. Track cold weather in the United States here. Cold Weather Safety: Experts offer tips to protect against common health hazards in freezing temperatures.

Tropical cyclone is the catch-all term for the powerful, spinning storms that feed off warm oceans and the strength of which is determined by wind speeds. The strongest are known as hurricanes in the Atlantic and typhoons in the Western Pacific and simply tropical cyclones in the South Pacific.

Satellite imagery can help determine the strength, size and cohesion of a storm. The stronger a storm becomes, the more likely an eye will form in the center. When the eye looks symmetrical, that often means the storm is not encountering anything to weaken it.

Tropical cyclone activity is buzzing across the Southern Hemisphere with as many as six cyclones simultaneously spinning around. According to the Accumulated Cyclone Energy tally complied by Colorado State University,