92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Wednesday, 25 January 2012
Evaluation of High Resolution Rapid Refresh (HRRR) Model Changes and Forecasts During 2011
Curtis R. Alexander, NOAA/ESRL/GSD and CIRES/Univ. of Colorado, Boulder, CO; and S. S. Weygandt, S. G. Benjamin, T. G. Smirnova, D. C. Dowell, P. Hofmann, E. P. James, M. Hu, H. Lin, J. M. Brown, and J. B. Olson

The High Resolution Rapid Refresh (HRRR) is a 3-km, convection permitting model, run hourly in real-time at the Global System Division (GSD) of the NOAA Earth System Research Laboratory (ESRL). The WRF-ARW-based HRRR is run out to fifteen hours over a domain covering the entire coterminous United States (CONUS), using initial and boundary conditions from an hourly-cycled 13-km mesoscale model, formerly the Rapid Update Cycle (RUC), and currently the Rapid Refresh (RR). The RR (and RUC) includes a diabatic digital filter-based radar reflectivity data assimilation procedure to improve specification of the divergent component of horizontal wind in areas of precipitation.

HRRR gridded output is used as input to an automated convective weather forecast product known as CoSPA. During the summer of 2011, an operational performance evaluation of CoSPA was conducted by the FAA to assess its impact on air traffic management (ATM) decision-making.

In this presentation, we will include an update of the changes implemented in the real-time HRRR model for 2011, including the adoption of the RR as a parent mesoscale model, along with results from an in-house assessment of HRRR model forecasts. Forecast evaluation from 2011 will include both the cool-season and warm-season and include verification of ATM related fields including ceiling, visibility, surface winds and reflectivity (convection).

Evaluation of model changes will include regional, diurnal (valid-time) lead-time, and multi-scale stratification of verification statistics. Case studies highlighting comparisons of the HRRR with the coarser-resolution parent model (RUC and/or RR) will be presented.

This research is partially in response to requirements and funding by the Federal Aviation Administration (FAA). The view expressed are those of the authors and do not necessarily represent the official policy or position of the FAA.

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