High impact extreme events such as severe floods, droughts, and heatwaves usually occur at the intersection of multiscale interactions of phenomena over a wide range of spatial and temporal scales from local to global and hours to interannual variability. The current modeling tools are inadequate to meet societal needs for prediction and projection of the extreme events in a changing climate and rising seas. To address this grand challenge, we developed a new capability by tracking the multiscale systems like ENSO, the Madden-Julian Oscillation (MJO), atmospheric rivers (ARs), jet stream, the ITCZ, easterly waves, tropical cyclones (TCs), and mesoscale convective systems (MCSs) using Multiscale Objects-Tracking and AI Climate Modeling for Extremes (Mosaic4E). One of the unique capabilities of Mosaic4E is the MJO Large-scale Precipitation Tracking (LPT) that can identify large-scale convective heating over the NH and SH can be used to study blocking patterns that are fundamental to heat waves and drought, which is not possible with the traditional MJO RMM index. When the MJO convection/precipitation is in the NH, it has a direct impact on the blocking patterns influencing the heatwaves and flooding and drought events. The MJO-LPT represents the subseasonal-2-seasonal (S2) time scale bridging the weather and climate and is a key for better understanding and predicting extreme events. The multiscale tracking capability will be enhanced by AI/ML tools in Mosaic4E for identifying, understanding, and predicting the extreme events. Mosaic4E is developed and tested using satellite and in situ observations as well as the ERA5 reanalysis data from 1979-2024. Mosaic4E has shown high skills in coastal flooding over the US and is currently tested globally. Applications is drought and heatwaves will be discussed as well.