Whethertheinitialconditionscontainpronouncedmesoscalesignalsisimportanttothesimulationofthesouthwestvortex.Aneastward-movingsouthwestvortexissimulatedusingthePSU/NCARMM5.Amodestdegreeofsuccessisachieved,butthemostseriousfailureisthattheformationanddisplacementofthesimulatedvortexinitsearlyphaseareaboutfourteenhourslaterthantheobservedvortex.Consideringtherelativelysparsedataonthemesoscalevortexandinanattempttounderstandthecauseoftheforecastfailure,anadjointmodelisusedtoexaminethesensitivityofthesouthwestvortextoperturbationsofinitialconditions.Theadjointsensitivityindicateshowsmallperturbationsofmodelvariablesattheinitialtimeinthemodeldomaincaninfluencethevortex.Alargesensitivityforzonalwindislocatedunder400hPa,alargesensitivityformeridionalwindislocatedunder500hPa,alargesensitivityfortemperatureislocatedbetween500and900hPa,andalmostallofthelargesensitivityareasarelocatedinthesouthwesternarea.Basedontheadjointsensitivityresults,perturbationsareaddedtoinitialconditionstoimprovethesimulationofthesouthwestvortex.Theresultsshowthattheinitialconditionswithperturbationscansuccessfullysimulatetheformationanddisplacementofthevortex;thewindperturbationsaddedtotheinitialconditionsappeartobeacyclonecirculationunderthemiddleleveloftheatmosphereinthesouthwesternareawithananticyclonecirculationtoitssouthwest;awatervaporperturbationaddedtoinitialconditionscanstrengthenthevortexandthespeedofitsdisplacement.
