  Recent extreme tropical cyclones caused extensive damages to critical civil
infrastructure globally. To better capture the unique hurricane wind
characteristics, a large eddy simulation (LES) Hurricane Boundary Layer (HBL)
model is developed by considering the variation of meso-scale kinematic and
thermodynamic conditions. An asymmetric model is adopted to obtain the gradient
wind velocity using the National Hurricane Center data. The meso-scale thermal
conditions are obtained by extracting the hourly air temperature and relative
humidity profiles from generated proxy soundings. Measurements recorded at the
Aransas County airport during Hurricane Harvey and that at the City of Naples
during Irma are used to validate the developed LES model. Research results show
that the simulated 10-minute average wind speed and direction are consistent
with the observations. The developed model can well predict the high wind
turbulences, which are around 20% in Hurricane Harvey and 26% in Hurricane
Irma. The 3-s gust wind speeds reach 62.4 m/s at 10-m elevation during
Hurricane Harvey and 53.5 m/s at 15-m elevation during Hurricane Irma, close to
the field observed data of 61.3 m/s and 54.2 m/s, respectively. The simulated
3-s gust factors are close to the observation except at some moments with
significant variations because of the poorly understood physical phenomena. The
simulated wind spectrum in longitudinal and lateral directions agrees well with
the observed results. In summary, the developed LES-based HBL model can capture
the main characteristics of hurricane structure and turbulence characteristics
and is applicable for modeling civil infrastructure exposed to hurricanes.
