Forecasting Techniques Utilized by the Forecast Branch of the National Meteorological Center During a Major Convective Rainfall Event

Abstract

Meteorologists within the Forecast Branch (FB) of the National Meteorological Center (NMC) produce operational quantitative precipitation forecasts (QPFs). These manual forecasts are prepared utilizing various forecasting techniques, which are based on the subjective analysis and interpretation of the observed data and numerical model output. The manual QPFs from NMC generally have proven very successful in improving model QPF. This paper discusses several of the forecasting techniques employed by the FB, emphasizing the importance of subjective interpretation of the model guidance. The use of these methods in preparing a manual QPF for a heavy convective rainfall and flash-flood event that occurred over the southern Plains on 27?28 May 1987 is then examined. Results indicate that the manual QPF was quite successful in improving the models? QPF and generally related well to the observed rainfall of up to 8 inches in this case. Thus, the importance of utilizing subjective techniques in preparing precipitation forecasts is illustrated.