Global Repository | Documentation for the Hurricane Weather Research and Forecasting (HWRF) Model

Documentation for the Hurricane Weather Research and Forecasting (HWRF) Model


Note: The following information applies to the 2012 operational version of HWRF.

Model type: Full physics, three dimensional dynamical model
Model timeliness: Late
Model status: Operational
Basins run in: AL, EP, WP, and IO
ATCF TECH identifier: HWRF
Forecast period: 0 to 126 hours
Included in TCGP: AL, EP, CP, WP, and IO
Domain: Three domains:
D01 (parent domain): 216 x 432 points, 80 x 80 deg, 27 km grid spacing
D02 (intermediate nest): 88 x 170 points, 11 x 10 deg, 9 km grid spacing
D03 (inner nest): 154 x 272 points, 6.0 x 5.5 deg, 3 km grid spacing
Domain top: 50 hPa
Vertical coordinate (# of levels): Sigma-pressure hybrid coordinates (42 levels)
Grid: Arakawa E-grid on rotated latitude and longitude projection
Cumulus parameterization: Simplified Arakawa-Schubert (SAS) scheme
Microphysics parameterization: Ferrier scheme
Boundary layer parameterization: GFS PBL (non-local mixing)
Radiation parameterization: GFDL radiation scheme
Ocean coupling: Full 3D POM coupled in AL basin, 1D POM coupled in EP basin and no ocean coupling in WP and IO basins
Initialization method: Grid-scale Statistical Interpolation (GSI) with vortex bogusing method
Initial and boundary conditions: Analysis and forecast data of NCEP Global Forecast System
Primary contact: Dr. Vijay Tallapragada, Hurricane Team Leader, NOAA/NWS/NCEP/EMC
Official model website:
Scientific documentation:
User's Webpage (community code):
User's Guide:
HWRF Products Portal site:

Brief Technical Description

The HWRF system is one of the NOAA's operational regional hurricane models, which has two vortex following finer nest domains with grid space of 9 and 3km resolution respectively with75 by 75 degree outer most static domain (27km). The HWRF system consists of a set of pre-processors that include vortex initialization software, two numerical forecast models (one for atmosphere and one for ocean), and a set of post-processors. The atmospheric pre-processors of the HWRF include procedures of interpolating GFS spectral data to HWRF model grids, constructing an initial vortex consistent to observation, and assimilating observation data. The initial and lateral boundary data for the HWRF model are the final product of the pre-processors. A separate ocean initialization that includes feature based assimilation of oceanic conditions and a spin-up phase based on observed tropical cyclone location and intensity and will generate initial conditions for the ocean model. Using these IC/BC data, the HWRF coupled modeling system predicts the location and intensity of a storm up to five days into the future. The dynamic core of the HWRF model is originated from WRF-NMM while some of dynamic features are modified to hurricane conditions, such as horizontal diffusion, vortex following algorithm and other characteristics. The physics suite of the HWRF model is also designed towards more appropriate representation of tropical conditions. Some examples are modifying air-sea exchange coefficients and vertical diffusivity inside boundary layer. The post-processors of HWRF system are built upon NHC's requests. The major products are hurricane track and intensity at 6-hrly interval, high temporal frequency data for storm location, maximum wind and minimum pressure, swaths for maximum wind and rainfall totals, synthetic satellite imagery, vertical wind shear plot, vertical cross-sections of major variables and other graphical products generated from the model output.




The information in this page was provided by Young Kwon (NOAA/EMC) on 07 December 2012. It has been reviewed by Dr. Vijay Tallapragada.