Theimpactsofsoilmoisture(SM)onheavyrainfallandthedevelopmentofMesoscaleConvectionSystems(MCSs)areinvestigatedthrough24-hnumericalsimulationsoftwoheavyrainfalleventsthatoccurredrespectivelyon28March2009(Case1)and6May2010(Case2)oversouthernChina.ThenumericalsimulationswerecarriedoutwithWRFanditscoupledNoahLSM(LandSurfaceModel).First,comparativeexperimentsweredrivenbytwodifferentSMdatasourcesfromNCEP-FNLandNASA-GLDAS.Secondary,withtherundrivenbyNASA-GLDASdataasacontrolone,aseriesofsensitivitytestswithdifferentdegreeof(20%,60%)increaseordecreaseintheinitialSMwereperformedtoexaminetheimpactofSMonthesimulations.Comparativeexperimentresultsshowthatthe24-hsimulatedcumulativerainfalldistributionsarenotsubstantiallyaffectedbytheapplicationofthetwodifferentSMdata,whiletheprecipitationintensityischangedtosomeextent.ForecastskillscoresshowthatsimulationwithNASA-GLDASSMdatacanleadtosomeimprovement,especiallyintheheavyrain(芏50mm)forecast,wherethereisupto5%increaseintheTSscore.SensitivitytestanalysisfoundthatapredominantlypositivefeedbackofSMonprecipitationexistedinthesetwoheavyraineventsbutnotwithcompletelythesamefeatures.Organizationoftheheavyrainfall-producingMCSseemstohaveanimpactonthefeedbackprocessbetweenSMandprecipitation.ForCase1,theMCSwaspoorlyorganizedandoccurredlocallyinlateafternoon,andtheincreaseofSMonlycausedaslightenhancementofprecipitation.Driersoilwasfoundtoresultinanapparentdecreaseofrainfallintensity,indicatingthatprecipitationismoresensitivetoSMreduction.ForCase2,astheheavyrainwascausedbyawell-organizedMCSwithsustainedprecipitation,therainfallismoresensitivetoSMincrease,whichbringsmorerainfall.Additionally,distinctivefeedbackeffectswereidentifiedfromdifferentstagesanddifferentorganizationofMCS,withstr
