Probabilistic Tracking of Heavy Precipitation Objects on Sub-Hourly Timescales

Forecasting excessive precipitation on the sub-hourly scale remains a challenge for warning operations, which ultimately affects life and property. Verifying quantitative precipitation forecasts using observational data is a key component of the forecast evaluation process. This is important for quantifying model biases regarding precipitation intensity, placement, and coverage, which can later be used to improve model forecasting of precipitation. To address this problem, numerous operational forecasting products within the Weather Prediction Center (WPC) are used to probabilistically quantify precipitation objects. Using NCAR’s Model Evaluation Tools (MET) Method for Object-based Diagnostic Evaluation in the Mode Time Domain (MTD) tool, numerical models, such as the High Resolution Rapid Refresh (HRRR) model, can be used to identify objects of heavy precipitation above a certain threshold on both the hourly and sub-hourly (15-minute) scales. Precipitation verification statistics such as the Brier Score will be computed using the Multi-Radar Multi-Sensor (MRMS) system in different precipitation regimes and regions to quantify the performance of this sub-hourly product. Further, MRMS mid-level rotation tracks will be incorporated into this product to better identify precipitation objects associated with small-scale rotating features which are known to increase precipitation efficiency.