On the Use of Dual-Doppler Radar Measurements for Very Short-Term Wind Power Forecasts

Very short-term forecasts of wind power provide electricity market participants with extremely valuable information, especially in power systems with high penetration of wind energy. In very short-term horizons, statistical methods based on historical data are frequently used. This paper explores the use of dual-Doppler radar observations of wind speed and direction to derive five-minute ahead deterministic and probabilistic forecasts of wind power. An advection-based technique is introduced, which estimates the predictive densities of wind speed at the target wind turbine. In a case study, the proposed methodology is used to forecast the power generated by seven turbines in the North Sea with a temporal resolution of one minute. The radar-based forecast outperforms the persistence and climatology benchmarks in terms of overall forecasting skill. Results indicate that when a large spatial coverage of the inflow of the wind turbine is available, the proposed methodology is also able to generate reliable density forecasts. Future perspectives on the application of Doppler radar observations for very short-term wind power forecasting are discussed in this paper.

Tornadogenesis in the 12 May 2010 Supercell Thunderstorm Intercepted by VORTEX2 near Clinton, Oklahoma

The 12 May 2010 supercell thunderstorm intercepted by the Second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) is analyzed during a time period of strong low-level rotation in which dual-Doppler radar observations were collected. Two different cyclonic vortices are documented. The first vortex was “marginally tornadic” before abruptly weakening, following the development of a descending reflectivity core (DRC) similar to those that have been documented in past studies of supercells. The second vortex rapidly developed immediately north of the DRC shortly after the DRC reached low altitudes, and was associated with a tornado that produced damage near Clinton, Oklahoma. The paper explores the possible roles of the first vortex in triggering the DRC, the DRC in the subsequent initiation of a new updraft pulse on its flank, and the updraft pulse on the development of the second, stronger vortex. The Clinton storm case is, unfortunately, a nice example of the challenges in predicting tornadogenesis within supercell storms even in environments understood to be favorable for tornadoes.