Evaluation of Hurricane Maria Boundary Layer Structure in HWRF Using UAS Coyote and NOAA P-3 Aircraft Observations

The hurricane boundary layer produced by forecast models can be difficult to verify in the eyewall due to the sparsity of observations in that region. Uncrewed aircraft system (UAS) Coyotes are deployed via NOAA P-3 Hurricane Hunter aircraft and are capable of sampling the boundary layer in the eyewall region. During three missions into Hurricane Maria, UAS Coyotes collected in-situ observations in the hurricane boundary layer eyewall region. These Coyote observations and coincident dropsonde profiles provide a novel dataset to evaluate the inner-core boundary layer structure in HWRF model forecasts of Hurricane Maria. Equivalent Coyote tracks and dropsondes are simulated from multiple 48-hour forecast fields by normalizing the Coyote and dropsonde paths executed in Hurricane Maria using storm relative radial and azimuthal locations. Forecasts vary in boundary layer parameters within the current operational scheme. This study focuses on evaluating the hurricane boundary layer structure in Hurricane Maria using comparisons of observed data and their simulated counterparts.