Beyond the 2011 Rapid Refresh: Hourly Updated Numerical Weather Prediction Guidance from NOAA for Aviation from 2012-2020

A sequence of significant changes are slated over the next several years to improve the NOAA hourly updated numerical weather prediction (NWP) guidance for aviation and other short-range forecast users well beyond the initial Rapid Refresh implementation at NCEP currently expected in September 2011. These efforts are currently being supported by NOAA, FAA and DOE.

RR-2 (2012) - There will be an update to the Rapid Refresh in 2012, including upgrades to the WRF model with improvements to digital filter initialization and physical parameterizations for boundary-layer mixing and cloud microphysics. An improved cloud-hydrometeor analysis is also expected in the RR-2 as an enhancement to the GSI (Gridpoint Statistical Interpolation) assimilation, with improved forecasts for ceiling/visibility and convection. Initial work is already underway in these areas that will be discussed at the conference.

HRRR - The 3km hourly-updated High-Resolution Rapid Refresh will be improved each year, with the same physics improvements for boundary-layer and microphysics expected for the WRF within the 13km Rapid Refresh to also be applied at 3km resolution. In each of these areas, extensive 3km sensitivity testing will be conducted with subsequent parameterization revisions occurring as a likely result. Radar reflectivity and radial wind assimilation is expected to be successfully applied at 3km resolution. Again, testing is already underway in these areas and will be summarized at the meeting.

Hybrid-ensemble Kalman filter/variational data assimilation, NARRE/HRRRE. Rapid progress is being made in this development at NCEP and at U.Oklahoma/CAPS (Center for Analysis and Prediction of Storms) (also partially funded by FAA/AWRP – Aviation Weather Research Program) toward regional ensemble assimilation applicable to the Rapid Refresh. This will improve initial conditions, especially for mesoscale circulations, pre-convective environment, ongoing convection, and winter storms for the Rapid Refresh and the HRRR. Moreover, this ensemble data assimilation will be central to improving probabilistic forecasts from the upcoming (currently scheduled in 2014) ~6-member North American Rapid Refresh Ensemble (NARRE). The same ensemble data assimilation within the NARRE (updating on an hourly basis) will allow effective initialization of a real-time multi-member HRRR ensemble (HRRRE) when additional computing resources allow. Looking still further ahead, preliminary plans for hourly updated global forecasts (nominally, a Global Rapid Refresh – GRR) will also be discussed.

The links between these areas (RR-2, HRRR, GSI-hybrid, NARRE, HRRRE, GRR) and promising efforts already underway in these directions will be described in the presentation.

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.