An Empirical Relationship between Water Vapor and Precipitation using Satellite Observations for Near-Real Time Forecasting Applications

The IPCC 5th Assessment found that the warming of the climate system is unequivocal and the probability of extreme events such as heat waves, droughts, and floods will increase. Society is highly vulnerable to these extreme weather events, through impacts such as disruption of food production, water supply, health, and damage of infrastructure. Forecasting and monitoring of extreme weather events is essential for mitigation of societal impacts.

Forecasting precipitation estimates in real time is dire for flood monitoring and disaster management. A 10-year empirical relationship has been derived between Precipitable Water Vapor (PWV) and precipitation by using the NASA Atmospheric Infrared Sounder daily gridded PWV product and the NASA Tropical Rainfall Measuring Mission daily gridded precipitation total. In addition, a 10-year relationship has been derived between the NASA AIRS PWV product and the NWS AHPS Precipitation product for comparison. Near real time PWV observations from AIRS on Aqua are available through the Goddard Earth Sciences Data and Information Service Center and from the ground-based SuomiNet GPS stations through UCAR. These near-real time observations along with the derived climatological relationship can be used to create precipitation precipitation potential estimates; the max amount of precipitation that can occur based on the moisture availability. Furthermore, the potential contribution of using the direct broadcasting of the NUCAPS ATMS/CrIS PWV products will be demonstrated; highlighting the advantages of applying this relationship in near-real time for flash flood monitoring and risk management.