ESRL/PSD Seminar Series

The verification of extreme QPFs is highly important to improving the prediction of extreme events by identifying and evaluating forecast trends, biases, and errors and to monitoring forecast progress and improvement. As part of its quantitative precipitation forecast (QPF) major activity area (MAA), NOAA’s Hydrometeorology Testbed (HMT) partnered with the National Centers for Environmental Prediction (NCEP) Weather Prediction Center (WPC) to benchmark and analyze the performance of NCEP/WPC’s 32-km gridded QPFs for extreme precipitation events over an 11 year period (2001-2011). Although WPC is a national center, providing national guidance, this analysis calculates and applies regional extreme precipitation thresholds (i.e., 99th and 99.9th percentile precipitation values) for each River Forecast Center (RFC) region. Extreme QPF performance was evaluated based on five verification metrics: probability of detection (POD), false alarm ratio (FAR), critical success index (CSI), frequency bias, and conditional mean absolute error (MAEcond). These scores were chosen as they are easily understood by operational forecasters. This presentation will show the results of this analysis, how NCEP/WPC is using the results to improve their guidance, and the next steps for HMT’s QPF verification.