Research on Hourly Precipitation Correction Method for CMA_GD(R1)Based on MODE Spatial Verification
LI Li
LIAO Fei
GAO Wenjun
SU Ran
Abstract：To address the spatiotemporal uncertainty in precipitation forecasts from the high-resolution regional numerical weather prediction model CMA_GD(R1),this study takes a Dragon Boat Water rainfall event in Guangdong from May 22 to 23,2023,as an example.By utilizing the MODE method,objective physical descriptors such as centroid distance,major axis angle difference,area ratio,overlapping area,and minimum distance between observed and forecasted precipitation objects are established.This forms a quan-titative method for assessing the similarity between observed and forecasted precipitation objects.A bias cor-rection method based on matching degree is proposed to objectively adjust precipitation forecasts.The results indicate the following.(1)During this rainfall event,the CMA_GD(R1)model predominantly produced false alarms in 1-hour precipitation forecasts with a lead time of 1-6 hours.(2)When the total comprehen-sive similarity score MMI(O+F)exceeds 0.6,the TS score of the precipitation forecast corrected based on centroid distance can improve to above 0.2,indicating that the centroid distance correction method effective-ly enhances the TS score when the spatial pattern of the forecasted rainfall area is closer to observations.This study provides a novel objective framework for improving high-resolution precipitation forecasts by integrating spatial verification and bias correction,offering practical value for operational meteorology and disaster pre-vention.
Keywords：synopticsCMA_GD(R1)MODE methodprecipitation forecastcorrection method
Publication Date：2025-06-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 17-21 )