This bulletin was developed for regular weekly publication with the aim of monitoring rainfall at 30-day intervals, scheduled to be updated on Thursdays. Its main data source is the MERGE/GPM data set published by the National Institute for Space Research (INPE), which consists of observed precipitation on the surface and satellite precipitation estimates made available in the form of grid points. This work processes and uses statistical techniques to identify river basins that eventually or for consecutive periods present conditions of excess or deficit precipitation that could put human activities in the region at risk. Qualitative forecasts of precipitation conditions over the major basins are also drawn up for the 7/14 day time horizon. This product is primarily intended to provide decision-makers with reliable information in good time so that action can be taken to mitigate the possible harmful consequences. The area covered is the main hydrographic basins that make up the Amazon Basin, the delimitation of the basins was based on data published at: https://www.hydrosheds.org/ where hydrographic information is available on a global and regional scale including drainage networks, land orientation, sub-basin boundaries at various scales based on data collected by NASA's Shuttle Radar Topography Mission (SRTM) program.