|hvc||False color image, derived by making a combination of the visible and infrared channels of the NOAA satellites. Image color represents temperature - not representative of real 'earth color'|
|ir||Infrared: This is a direct channel of the NOAA satellites, which is always present, unlike the other channel, which switches from visible to another infrared band during day/night|
|mcir||Map Color IR: If visible light is not available, MCIR uses an internal map in the decoding software to distinguish between continent and water, and still be able to render a color image. The other information is taken only from the IR channel|
|msa||Multispectral analysis, sophisticated name to refer to yet another channel combination method (like HVC) which uses both NOAA channels to render a false color image.|
|mb||Indicates probability of thunder storms. Areas of low-temperature clouds are enhanced to mark possible strong storms.|
|no||Infrared, but extreme low temperature are rendered in strong colors. I particularly like this mode, as it indicates possible areas of dangerously active cloud formations better than any other mode. Black, and even worse - white areas, are at -60 C or less indicating very strong possibility of hail and other problems.|
|vis||Visible range. These pictures are logically only available during daytime imagery.|
|za||Infrared, with non-linear representation, enhancing the temperature differences in cloud formations. This permits finding the storm centers.|
If a filename has a mode listed in the table above, but has an extra 'm' at the end (like 'irm', 'mcirm', etc.), then the images are actually mosaics: two or more images, obtained from consecutive satellite passes, glued together into one (larger) image.
From where I live, I rarely have the opportunity to obtain two passes of sufficient quality to merit the combination into a mosaic. Still, when it does happen, the result is normally worth the extra download time!