Extended Abstract

form. The initial conditions of ensemble member are defined by adding (subtracting) initialperturbation, which is generated by SVs to the control analysis field.Hong Kong Observatory develops a nowcasting rainstorm forecasting system calledRAPIDS (Rainstorm Analysis & Prediction Integrated Data-processing System) to blend ormerge the SWIRLS with NWP. SWIRLS makes use of raingauge data over Hong Kong tocalibrate radar reflectivity in real time, however, it becomes less skillful with time when therainstorm motion is erratic or when echoes develop or dissipate rapidly.2.3.2 Verification for TC QPFsIt is generally accepted that QPSs must first be validated against observations to identifymodel limitations and biases and possible areas for improvement in the forecasts. StandardQPF validation techniques, such as bias and equitable threat scores (ETSs), can be used toassess some aspects of TC QPFs. However, an additional set of QPF validation techniquesspecific to TCs is needed in order to evaluate the ability of the models to predict rainfallattributes unique to TCs, such as the extreme rain amounts so often responsible for the deathand damage accompanying landfall (Marchok et al. 2007).3 RecommendationsTo meet the needs of TC-related disaster mitigation, observational and forecastingtechniques relating to heavy rainfall caused by LTCs still require urgent improvements andsignificant development.Heavy rainfall and flooding caused by LTCs are recognized as extreme weather events,but the science behind the behaviors of LTC rainfall is not currently understood to a greatenough extent.For numerical modeling, differences in the resolution and microphysicalparameterization likely cause distinct QPFs. Further improvements in microphysical andboundary layer parameterization are required to obtain successful TC QPFs.For data assimilation, more realistic microphysics scheme needs to be included in theradar data assimilation.One of the major reasons for the slow pace of improvement in TC QPFs may bedeficiencies in the collection and assimilation of real-time inner core data into numericalweather prediction models. Due to cloud and rain effect, satellite retrieved products usuallyhave large uncertainties under cloudy and precipitating areas, thus most of the cloudy andrain-effected data are rejected during the quality control procedures in data assimilation.BibliographyBuckley C. D., Hood R. E. and LaFontaine F. J., 2009: Application of Airborne Passive MicrowaveObservations for Monitoring Inland Flooding Caused by Tropical Cyclones. J. Atmos. OceanicTechnol., 26, 2051-2070.Bermejo, R. and A. Staniforth, 1992: The conversion of Semi-Lagrangian advection scheme toquasi-monotone schemes, Mon. Wea. Rev., 120, 2622-2632.Bonell, M. and J. Callaghan, 2008: The synoptic meteorology of high rainfalls and the storm runoffresponse in the Wet Tropics. Living in a Dynamic Tropical Forest Landscape, N. Stork and S. Turton,Eds. Blackwell Press, 448 pp.Callaghan, J. and M. Bonell 2005. Synoptic and mesoscale rain producing systems in the humid tropics.Forests, Water and People in the Humid Tropics International Hydrological Series, M. Bonell, and L.A. Bruijnzeel, Eds., Cambridge University Press, 925 pp.Callaghan, J. and M. Bonell 2005. An overview of the Meteorology and climatology of the humid tropics.Forests, Water and People in the Humid Tropics International Hydrological Series, M.Bonell, and L.A. Bruijnzeel, Eds., Cambridge University Press, 925 pp.Cartwright, T. J., and T. N. Krishnamurti, 2007: Warm season mesoscale superensemble precipitationforecasts in the southeastern United States. Wea. Forecasting, 22, 873–886.-129-