Extended Abstract

Fig.2 Severe tropical storm Bilis (0604) interact with south west monsoon flowRemnant vortex would obt ain baro clinic poten tial energy from the i nteractionbetween the remnant and mid-latitude trough, The potential energy it obtained wouldconvert into kinetic energy to reinv igorate the remnant and increase the rainfall. Onthe other hand, when monsoon surge and its south west stream flow with wet cloudcluster merge and embroil into a LTC or its remnant which would obtain water vapourand latent heat. It w ould help remnant sustaining longer per iod over lan d to inc reaseTC rai nfall (Dong et al, 2010). S evere tropical stor m Bili s (0604) is one of thosetypical cases (Fig.2) Whi ch sustained five days over land and bring about very heavyrainfall in south China. Bilis interact with the humid south west monsoon flow andstrong moisture flux which played a major role for this very heavy rainfall.Some st udies (Zeng et al, 2002 ) also showed that the h eat island effect, landsurface topography, cod air intrusion and jet stream coupling in upper level and lowerlayer play an important role in TC heavy rainfall.Most of the LTCs with rain resuscitation made landfall in south east coastal areaof Chi na. Those L TCs have tw o motion trends aft er th eir landfall, n amely movetowardnorth and west respectively. LTCs with northward motion trend may interactwith mid-latitude trough to g ain b aroclinic p otential energy. So me of them have a-27-