Satellite, lightning, sounding, and model data for nowcasting heavy rainfall from Mesoscale Convective Systems (MCS's)

Satellite, lightning, sounding, and model data are used for nowcasting heavy rainfall from Mesoscale Convective Systems (MCSs). Satellite data include Geostationary Operational Environmental Satellite (GOES) 10.7-µm imagery which are used to examine the life cycles of MCSs. National Oceanic and Atmospheric Administration (NOAA)-15, -16, and -17 polar orbiting satellites can help analyze the rainfall rates via the Advanced Microwave Sounding Unit (AMSU). Cloud-to-ground (CG) lightning data from the National Lightning Detection Network (NLDN) are superimposed on the GOES 10.7-µm imagery in order to determine the location and trends of the CG activity embedded within the MCS. This information by itself is excellent for nowcasting MCS propagation, which in turn provides short-range forecasts of rainfall. However, additional pertinent information is available from the sounding and model data for adding skill to the propagation and rainfall nowcasts. Soundings offer moisture, stability and wind data relevant to assessing propagation and the precipitation efficiency of the environment. Stability reversals between 0°C and -10°C may lead to more frequent lightning flashes and heavier rainfal if they occur in a precipitation-efficient environment; meanwhile, dry environments would be prone to wildfires. Stability reversal refers to a temperature lapse rate that changes from potentially unstable in the lower portion of the MCS-producing air mass to potentially stable in the middle troposphere. Numerical weather prediction models (North American Model (NAM); Global Forecast System (GFS), etc.) are excellent for detecting low-level equivalent potential energy, wind, thickness, and vertical motion fields, all of which are also significant for nowcasting MCS initiation and propagation.