NOAA Forecast Systems Laboratory, Boulder, Colorado 80303 U.S.AThe Weather Research and Forecast (WRF) project is a multi-institutional effort to develop an advanced mesoscale forecast and data assimilation system that is accurate, efficient, and scalable across a range of scales and over a host of computer platforms. The first release, WRF 1.0, was November 30, 2000, with operational deployment targeted for the 2004-05 time frame. This paper provides an overview of the project and current status of the WRF development effort in the areas of numerics and physics, software and data architecture, and single-source parallelism and performance portability.

A unique, high resolution, hydroclimate re-analysis, 40-plus-year (October 1979 – September 2021) 4-km (named as CONUS404), has been created using the Weather Research and Forecast model by dynamically downscaling of the fifth generation ECMWF (European Centre for Medium-Range Weather Forecasts) atmospheric reanalysis of the global climate dataset (ERA5) over the conterminous U.S. The paper describes the approach for generating the dataset, provides an initial evaluation, including biases, and indicates how interested users can access the data. The motivation for creating this National Center for Atmospheric Research (NCAR)-U. S. Geological Survey (USGS) collaborative dataset is to provide research and end-user communities with a high-resolution, self-consistent, long-term, continental-scale hydroclimate dataset appropriate for forcing hydrological models and conducting hydroclimate scientific analyses over the conterminous U.S. The data are archived and accessible on the USGS Black Pearl Tape system and on the NCAR super-computer Campaign storage system.