Infrared Satellite Interpretation October 11, 2004 This infrared
satellite image from the NOAA GOES-12 satellite shows a grayish-
white shading over a large portion of the upper Middle West at
1115 UTC (6:15 a.m. Central Daylight Time) on September 28,
2004. At first glance, you might think that clouds covered most
of the region, but sky conditions were generally clear, as
supported by a gaggle of early morning temperatures in the 30's
(map above). So, for the most part, you're looking at cold
ground. You can get a sense of the clear sky conditions when you
notice the dark, sinuous outline of the Missouri River in South
Dakota (other bodies of water, like lakes in Minnesota, also
appear dark). Bodies of water cool more slowly than the land
during autumn, so the Missouri is warmer than the cold ground
surrounding it. Thus, on cold, clear mornings in early fall, the
dark outlines of warm bodies of water that are surrounded by
cold ground tend to stand out on conventional infrared satellite
imagery.