Water vapour can be seen as the fuel which powers tropospheric processes. It can be transported over long distances across the planet and may release its latent energy when it condenses.

In the following chapters we will first have a closer look at the horizontal transport of water vapour within the Earth's troposphere with the help of TPW products and then investigate their benefits for predicting "moist" convection.

Figure 1: Morphed composite image loop of TPW (26 August 2014, 09 UTC to 29 August 2014, 08 UTC). Hurricane Cristobal moving north-east. Source CIMSS.