Here are forecasts and rain accumulations for South Asia, which is home to the strongest monsoon on the planet.
Forecast for wind and precipitation
This animation shows the forecast of precipitation (color shading) and horizontal winds at 850 hPa, which is about 1.5 km above sea level. The precipitation is the accumulation over the previous 6-hour period, in millimeters (1 inch = 25 mm), and winds are measured in m/s (1 m/s = 2.2 miles per hour). This is from a single deterministic forecast; the ensemble, probabilistic forecast for rainfall averaged over the red box (the core monsoon region) is shown below.
All forecast data is from the Global Ensemble Forecast System (GEFS) of the U.S. National Centers for Environmental Prediction (NCEP). All forecasts use an initial atmospheric state at the time indicated on the plot (note that 00Z is midnight Universal Coordinated Time, which is 5:30 am in India or 8 pm the previous day in New York [EDT]).
The below plots show the daily rainfall and the total seasonal accumulation of precipitation, compared to the historical average, all averaged over the red box in the map above.