Probability of precipitation for the given period.
If precipitation includes rain, snowfall or other frozen/winter precipitation types.
Within the context of hourly data, precipProb is reported every 6th hour (with 5 intervening null values). The reported precipitation probability is for the 6 hour period ending with the hour that contains the reported data. For example, if there is a 20% precipitation probability reported for the 8 A.M. hour, this means that there is a 20% chance of precipitation occurring between 2:00 A.M. and 8:00 A.M.
