Microphysics Observations in Hurricanes

Tropical cyclone track forecasts had made significant progress in the past several decades. One of the main factors is better forecast guidance provided by Numerical Weather Prediction (NWP) models. However, our progress in forecasting tropical cyclone intensity including rapid intensification has advanced slowly due to our limited understanding of cloud, precipitation, and latent heating processes within tropical cyclones in NWP models. In order to improve the representation of those microphysical processes and its interactions with other physics and dynamics, NOAA has been conducted observations of microphysics processes in hurricanes for four decades. In this study, we analyzed the microphysics data collected from deep convective regimes in the historical storm and stratiform regimes in the recent years. The particle size distributions of solid and liquid water showed that the gamma functions can represent these distributions more realistically than exponential functions. Some sensitivity simulations with these observed particle size distributions in GFDL's new Microphysics parameterization scheme will be performed to quantify the potential improvement for different microphysical processes.