WRF Reference Configurations

2000

In South Florida, mesosacle weather features have a significant impact on day to day weather forecasts as they represent the primary forcing. Some of these features are: tropical waves, seas breezes, land breezes, thermal troughs, and outflow boundaries. The warm waters of the ...

2010

Convection-allowing configurations of the WRF model were evaluated during the 2004 SPC/NSSL Spring Program in a simulated severe weather forecasting environment. The utility of the WRF forecasts was assessed in two different ways. First, WRF output was used in the preparation of daily experimental human forecasts for severe weather. These forecasts were compared to corresponding predictions made without access to WRF data to provide a measure of the impact of the experimental data on the human decision-making process. Second, WRF output was compared directly to output from current operational forecast models. Results indicate that human forecasts showed a small, but measurable improvement when forecasters had access to the high-resolution WRF output and, in the mean, the WRF output received higher ratings than the operational Eta model on subjective performance measures related to convective initiation, evolution, and mode. The results suggest that convection-allowing models have the potential to provide a value-added benefit to the traditional guidance package used by severe weather forecasters.

2000

2016

Radiosonde observations (RAOBs) are relatively sparse over central Texas. The closest RAOB launch site to College Station, Texas is in Fort Worth, Texas, about 250 km away. On-demand soundings were launched by Texas A&M University students in high-impact situations. Both the local NWS offices and the SPC requested RAOBs. These observations had value to forecasters in convective and winter weather situations. The purpose of this research was to find the value of on-demand RAOBs on a high-resolution NWP forecast for College Station. DA was done with 29 RAOBs using WRF, but also incorporated other observations from MADIS. In total, there were 116 simulations since four simulations were done for each RAOB. Using weather model analyses and observations from the EOL, MADIS, and NOAA, the simulations were evaluated. DTC-MET and SPoRT-MET tools utilized the datasets to provide verification. In some cases, DA of a single RAOB produced modest, positive impacts on the WRF forecast. Precipitation characterization and high precipitation amounts were improved in convective cases, while surface and low-level temperature forecast improvements were seen in short-range forecasts for winter cases. Benefit was spatially limited to areas near College Station, and was further limited when MADIS observations were assimilated. Future work supports RAOB launches in high-impact situations; however, real-time DA of these RAOBs is not a high priority. Others also deserve mention for supplemental help along the way. Dr. Jon Poterjoy at NCAR provided some helpful MatLab scripts for RAOB DA, Lance Wood provided references to forecast verification scripts, and Christine Paschal analyzed the RAOBs before they were used in WRF-DA. Two help desks were invaluable to troubleshooting, which were the WRF help desk at NCAR, and the DTC-MET help desk. Support was also received from so many colleagues, friends, and family. For these people, I am grateful.

MM5/WRF User's Workshop, 2004