Why clouds not appeared on Satelite immages while there is absoultely overcast conditions in our city karachi.

Question

Today there is a totally overcast condition in my city but the recent / most current Satellite Picture (IR) is not showing even tracing??????????

Rizwan

Answer 1

Because the IR satellite uses higher frequency and its not able to detect warm temperature clouds. Most overcast clouds are a very low around 4,000 feet or lower. Use the shortwave satellite (if available) to detect lower clouds.

Answer 2

Yes, The IR basically detects cloud top temperatures, with the colder temperatures more pronounced on the image.  If there is a deck of relatively low clouds, then the cloud top temperature may be close to the surrounding surface temperature where it is clear, thus the image will not show much, if any difference between the two, giving the false impression that the sky is clear where the clouds actually exist.