Storm Products
Storm products are advanced radar-derived outputs that provide detailed insights into the structure, intensity, and potential severity of convective systems. They integrate multiple radar parameters to generate fields like Echo Top, Hail Detection, Storm-Relative Velocity (SRV), and Vertically Integrated Liquid (VIL). These products help meteorologists assess storm growth, identify hail cores and detect rotation within thunderstorms.
The Echo Top product provides a measurement of the maximum height of radar echoes above a threshold of 18.5 dBZ, effectively highlighting the vertical extent of precipitation within a storm. By identifying the highest regions where radar returns exceed this reflectivity level, it offers insight into the structure and intensity of convective systems.
High echo top values are a strong indicator of powerful updrafts, which are often associated with severe thunderstorms capable of producing large hail, strong winds, and even tornadoes. Meteorologists use this information
to assess storm severity, monitor storm development, and anticipate potentially hazardous weather conditions.
Vertically integrated liquid shows how much liquid precipitation is present in the cloud. It’s mostly influenced by the size of targets (more than their quantity), thus the presence of large drops or hail means larger values. Severe thunderstorms with high echo tops tend to have the highest VIL values.
VIL density product is VIL value divided by ECHO TOP value, which gives us water content in specific volume. Units are g/m3. Values over 3 g/m3 indicate the possibility of large hail, while values over 4 g/m3 mean that large hail is present in basically all cases.
Echo Thickness is a difference between Echo Top and Echo Base (default reflectivity threshold 18.5 dBZ). Echo Base is the minimum height of the echo that exceeds a predefined threshold (default 18.5 dBZ).
Stratiform – Convective Precipitation Partitioning is a product designed to automatically classify radar-derived precipitation into stratiform and convective components. The product processes volumetric radar data to identify regions dominated by widespread, steady stratiform rain and those containing localized convective cells. Using reflectivity structure, vertical profile analysis, and echo-top characteristics, it produces a map that highlights the distribution and relative contribution of each precipitation type.
The MESH (Maximum Expected Size of Hail) product provides an estimation of the potential size of hailstones within a storm. By analyzing radar reflectivity data and other meteorological parameters, it identifies regions where severe hail is most likely to form. This information allows meteorologists and emergency services to assess the severity of ongoing storms.
The POSH product tells us the probability of severe hail (>2 cm) at a given place.
Microburst Detection product detects microbursts within the storms. The algorithm uses a combination of polarimetric variables and derived products, such as KDP or VIL. The output is a table with information whether downburst was detected.
Mesocyclone Detection product detects if the storm is rotating. For each storm, horizontal cyclonic shear (HCS) and reflectivity is measured. The output is a table with information whether mesocyclone was detected.
Storm Relative Velocity represents the difference between the Doppler-measured velocity of precipitation particles and the overall movement of the storm. By accounting for and removing the storm’s motion, this product effectively provides velocity data as if the storm were stationary, allowing meteorologists to analyze internal windpatterns more clearly.
This adjustment makes it easier to identify important features such as rotation within the storm.