The AWC uses two geostationary satellites (GOES8 and GOES10) to produce
satellite images over the U.S.
The visible image shows the earth very similar to how humans see it
with their eyes. Clouds and snow appear bright white (high albedo/reflectance) but
oceans and trees are much dimmer. During local daylight hours the image is generated
from the visible channel, and at night it is a derived "fog" image which
emphasizes the low clouds. A saw-tooth boundary between the different images is visible
across the domestic land mass as night turns to day and/or day turns to night.
For more detailed information on Vis/Fog images
The infrared image shows the earth in a manner that correlates with
temperature. Generally speaking, the warmer an object, the more infrared energy it emits
(gives off). The satellite sensor measures this energy and calibrates it to temperature.
High clouds are usually cold whereas low clouds near the earth's surface are usually
warm. Likewise, the land itself is usually even warmer. The data measured by the
satellite are calibrated and colorized according to the temperature with dark and gray
shades representing higher (warmer) temperatures and white, blue, and up through red
shades representing lower (cooler) temperatures.
The water vapor image shows the earth in a manner that correlates to
quantity of water vapor in the upper portions of the atmosphere (25,000 feet and
higher). The colors displayed on the water vapor image correspond to temperature values
but there is no direct relationship between these values and the temperatures of clouds
(as is the case for infrared images) since this image doesn't show clouds but high-level
water vapor instead. Locations of storm systems and jet streams are made apparent. In
general, regions displayed in shades of red are VERY dry in the upper atmosphere and
MAY correlate to crisp blue skies from a ground perspective. On the contrary, regions
displayed in shades of white or light through dark blue are indicative of high-level
moisture and may also indicate cloudiness. This cloudiness could be serious storms or
simply high-level cirrus. It is hard to say from this image alone, but the determination
could be made by using the other satellite images.