Improved Precipitation Forecasting for Iowa
Improved quantitative precipitation forecasts are necessary to ensure the most accurate prediction of streamflows and flooding. A state-of-the-art mesoscale model, the Weather Research and Forecasting (WRF) model developed by the U.S. atmospheric research community, is being used by IFC researchers to form an 8-member ensemble designed to provide the most accurate rainfall forecasts possible in the 6-48 hour period for Iowa. The ensemble uses mixed initial and lateral boundary conditions, along with mixed physical parameterizations, and is run with 4 km grid spacing to provide fine-sale detail.
Bias correction approaches are being tested on the ensemble output to improve the skill of rainfall forecasts relative to operational forecasts available from the Hydrometeorological Prediction Center of the National Weather Service.
Researchers are also continuing to examine the best design of the ensemble, and the possibility of using bias corrections that are a function of large-scale meteorological conditions.
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