Comparison of the Performance of the Observation-Based Hybrid EDMF and EDMF-TKE PBL Schemes in 2020 Tropical Cyclone Forecasts from the Global-Nested Hurricane Analysis and Forecast System

Abstract Better representation of the planetary boundary layer (PBL) in numerical models is one keys to improving forecasts TC structure and intensity, including rapid intensification. To meet this goal, our recent work has used observations improve eddy-diffusivity mass flux with prognostic turbulent kinetic energy (EDMF-TKE) PBL scheme Hurricane Analysis Forecast System (HAFS). This study builds on that by comparing a modified version EDMF-TKE (MEDMF-TKE) hybrid EDMF based K -profile method (HEDMF-KP) 2020 HAFS-globalnest model. Verification statistics 101 cases season demonstrate MEDMF-TKE improves track forecasts, reduction large right bias seen HEDMF-KP forecasts. The comparison intensity performance mixed, but magnitude low at early forecast hours reduced use scheme, which produces wider range intensities. Wind radii particularly radius maximum wind speed (RMW), are also improved scheme. Composites inner-core above highlight explain differences between two sets having stronger shallower inflow layer, eyewall vertical velocity, more moisture region. A case Laura shows better represented subtropical ridge thus motion TC. Finally, analysis Delta through tangential budget highlights how why leads faster spinup vortex prediction