Eventually winds diminish, the pressure rise slow and blue skies dominate, signifying continental polar or, in the west, maritime polar air high pressure is approaching. After a day or so of fine weather, cirrus clouds may appear signifying the approach of the next weather system. Polar orbiter satellites provide strip coverage as they rotate around the earth. Coverage over any given point is provided just several times per day from these satellites. One set of sensors onboard the weather satellites measures the amount of radiation emitted which is proportional to the temperature.
Warm ground emits more radiation than high cold clouds.
We can with the right choice of a color table see clouds over the earth s surface. The typical color table uses dark colors for warm and white for cold temperatures. When you see very bright clouds on an infrared image, they are likely high clouds. They may be high cirrus clouds associated with fine weather beneath or high ice crystal blowoff from huge thunderstorms which are producing violent weather at the surface. These clouds will only be visible if their temperatures differ from the surrounding ground.