Current snow cover in the eastern United States
This imagery combines the latest half-hourly GOES infrared and visible images with NASA's "Blue Marble" data set to create real-time animations of the weather systems over the continental United States during the past 72 hours.
Visible satellite imagery detects sunlight reflected by the atmosphere, clouds, and Earth's surfaces. That's why clouds appear white and land and water are seen in shades of gray or black. One of the major advantages of visible imagery is that it has a higher resolution (about 0.6 miles) than infrared imagery, which allows analysts to distinguish smaller features in the atmosphere or on the surface. However, since visible imagery is produced by reflected sunlight, it is only available during the day time.
In contrast, Infrared satellite imagery detects heat radiating off of clouds and the surface of the Earth. Because clouds are colder than land and water, they can be detected easily in this kind of imagery, which is useful for determining the intensity of thunderstorms as well as the location of fog and low clouds. Moreover, because infrared imagery is based on heat rather than sunlight, it is available both day and night.
Infrared images can be "colorized" or "color-enhanced" to bring out details in cloud patterns. Depending on the type of enhancement, the colors are used to signify certain aspects of the data. These color enhancements are useful to meteorologists because the colors enable them to easily and quickly see features of special interest, such as cloud-top height. In this imagery, yellow and orange areas signify taller clouds, which often correlate with more active weather systems.
Water vapor imagery, which is useful for both determining locations of moisture and atmospheric circulations, is created using a wavelength sensitive to the content of water vapor in the atmosphere. In this imagery, bright blue and white areas indicate the presence of high water vapor or moisture content, whereas dark orange and brown areas indicate little or no moisture present.
VIIRS True Color
Although true color images like this may appear to be photographs of Earth, they aren't. They are created by combining the color channels of the Suomi NPP satellite’s Visible Infrared Imaging Radiometer Suite (VIIRS) instrument. These channels, which are sensitive to the red, green and blue (or RGB) wavelengths of light, are combined into one composite image. Several other channels are often also included to cancel out atmospheric interference that can cause a blurry picture.
RGB composites are used for many applications, such as differentiating snow/ice from cloud, ash/smoke from cloud, or even the boundaries between warm and cold air masses.
NOAA generates over 20 terabytes of data daily from satellites, buoys, radars, models, and many other sources. All of that data is archived and distributed by the National Centers for Environmental Information. These records include observations dating back to the earliest days of the United States and data about environmental conditions thousands of years ago.
In addition to the official data sources available from NCEI and the NOAA Data Catalog, several other websites and applications across NOAA have been designed to streamline access to our vast data holdings.
Over 150 data variables from satellites, weather models, climate models, and analyses are available to map, interact with, and download using NOAA View's Global Data Explorer.
Want to map or access the track info for any hurricane, typhoon, or cyclone since 1842? Try the Historical Hurricane Tracks mapping application.
Data Snapshots provides imagery and links to data for a variety of U.S. and global analyses, such as average temperatures, precipitation, drought, and severe weather.