MRMS = “Multi-Radar/Multi-Sensor Precipitation System”
A quantitative form of radar giving almost live precipitation rates, cumulative quantity of fallen precipitation, as well as precipitation type.
From NOAA’s description:
MRMS is a system with fully-automated algorithms that quickly and intelligently integrate data streams from multiple radars, surface and upper air observations, lightning detection systems, satellite observations, and forecast models.
Numerous two-dimensional multiple-sensor products offer assistance for hail, wind, tornado, quantitative precipitation estimations, convection, icing, and turbulence diagnosis.