Radars are machines that use beams (or pulses) of radiation (radio waves) to detect different kinds of precipitation (rain, snow, hail, etc.). Doppler radar allows a radar to detect not only precipitation, but also velocity, or motion within a cloud. This allows for the detection of rotation within thunderstorms, often the precursor to tornadoes. NEXRAD, or the next generation Doppler radars, are Doppler radars operated by the National Weather Service (166 of them in the lower 48 states). Many television stations also operate their own radars as well.
Helpful Radar Links:
(the following radars links are courtesy the National Weather Service)
NEXRAD from Atlanta, GA
NEXRAD from Birmingham, AL
NEXRAD from Montgomery, AL
NEXRAD from Warner Robins, GA
NEXRAD from Ft. Rucker, AL
NEXRAD from Moody AFB, GA
Other Radar Links:
Understanding how a radar works
Radar frequently asked questions and definitions
United States NEXRADs, courtesy College of DuPage
Another "pick a radar" site from the NWS
National and regional radar site from NWS
Weather satellites are instruments in orbit around the Earth with the main goal of monitoring weather and climate. It goes beyond just observing clouds, as sophisticated weather satellites can monitor many environmental factors like temperature, vegetation, ash and smoke clouds, ozone, ocean currents, and much more. Satellites are either "geostationary" (in an orbit above the equator that keeps them stationary with respect to the Earth below) or "polar orbiting" (in a north to south orbit that passes over both poles of the Earth). Geostationary satellites are about 22,300 miles above the Earth, while polar orbiting satellites are only about 530 miles above the surface (their closer range provides better resolution.
Satellites make the use of visible light to take pictures of clouds, smoke, smog, and dust which allow meteorologists to track weather systems. They are only useful during daylight hours. Infrared and thermal sensors allow satellites to observe ocean surface features, determine temperatures throughout the atmosphere (both over the land and ocean) and also determine the height and types of different clouds.
Helpful Satellite Links:
Local Satellite Images:
Other Satellite Links:
High-resolution (1 km) visible images (pick a state)
North American GOES images, including experimental images