Cloud usually is a trouble maker in satellite remote sensing. Jing however worked out an idea that uses the help of clouds to detect water vapor in the upper-troposphere and lower stratosphere (UTLS) region, where the retrieval is known to be especially challenging and water vapor variability at small spatial scales (<100km) had never been successfully retrieved by satellites. This work is accepted for publication in the Journal of Atmospheric and Oceanic Technology. Congratulations to Jing!