Investigating the Role of Coastal Upwelling and Synoptic Conditions in the Prediction of Wind Ramp Events

Efficient operation of offshore wind farms and the effective integration of this power into the electrical grid relies in part on accurate forecasting of the winds. Research has shown that numerical weather prediction models can make significant errors in forecasting wind ramps, particularly in the timing of the ramp and in the magnitude of the pre­ ramp wind speed, with the result of making wind farms potentially more expensive to operate. This study investigates the role of sea surface temperature variations, particularly those caused by coastal upwelling events, in influencing the model forecasting error of wind ramps for the Delaware and New Jersey wind energy areas. Sea surface temperature plays a role in the development of flow patterns that could result in ramps in the coastal region, including sea breezes and coastal storms. Offshore wind ramps will be simulated using the Weather Research and Forecasting model forced with different sea surface temperature fields as the bottom boundary condition, including a unique satellite sea surface temperature composite that preserves the cold coastal upwelling common in the region. Additionally, synoptic typing is used to identify and characterize model prediction of wind speed relative to the underlying synoptic meteorological conditions and the role they may play in ramp prediction. Model performance is evaluated against available offshore meteorological measurements, including vertical profiles where available.