Microwave observations yield important quantitative information about precipitation processes over land and ocean areas that are not covered by radar.

Areas of precipitation can be identified using AMSU and SSM/I measurements of cloud liquid water and scattering of high frequency microwave radiation by ice particles. The rain rate (RR) product shown here is computed by converting the liquid water content and/or scattering magnitude to mm/hr via a non-linear relationship determined from coincident radar measurements.

Rain rates derived from AMSU data show heavy precipitation occurring in association with Hurricane Georges over the island of Hispaniola on 23 September 1998. The TPW product in the bottom panel helps to show the extent of the storm. Satellite estimates of RR are becoming an important tool in assessing and subsequently predicting rainfall intensity and extent associated with oceanic storms that threaten land areas.