It is well recognized that long-term precipitation measurements are necessary for understanding and monitoring regional precipitation characteristics. This includes characteristics crucial for monitoring water resources and hazards, like floods and droughts. TRMM was the first NASA mission dedicated to observing precipitation. It operated from November 1997 to April 2015. The Global Precipitation Measurement (GPM) Mission launched in February 2014 as a follow-on to TRMM. Both TRMM and GPM satellites, together with additional national and international satellites, were used to produce multi-satellite products such as TMPA and IMERG. Until recently these two separate products covered different time periods. There was a lack of long-term, continuous, precipitation time series. 

Recently, GPM-IMERG retrospectively analysed TRMM-TMPA data to produce a consistent, combined precipitation time series from 2000-present. This extended IMERG data product is available at half-hourly resolution and 0.1x0.1 degree spatial resolution. The product will be useful for deriving long-term mean precipitation as reference. It will also help with monitoring extreme precipitation at regional scale.

These webinars will focus on analysis and interpretation of the new long-term IMERG data to derive regional precipitation statistics, focused on extreme dry and wet period monitoring and management. 


By the end of this training, attendees will be able to: 

  • Derive regional precipitation statistics (mean, standard deviation, anomalies, percentile values) 
  • Calculate and interpret the Standardized Precipitation Index (SPI) for assessing extreme dry and wet periods

Level and Format:

  • Advanced
  • Three, two-hour webinars
  • Lectures and hands-on exercises


Local, regional, state, federal, and international entities, including public and private sector organizations, engaged in water resources and disaster management.