Migration Alerts Nashville, TN, USA

BirdCast forecasts three nights into the future with reasonable accuracy (e.g. explaining up to 80% of the variation in migration intensity with weather data), based on previously published research. This range may be expanded in the future beyond the current 72 hour limit. Predictions for 24-72 hours in the future explained similar levels of variation in bird migration, but current limitations in the predictive power to forecast weather beyond 72 hours begin to decrease the explanatory power of forecasts.

A forecast on a particular night represents a prediction for the number of birds/km that will pass over a selected location during the night based on an analysis of 23 years worth of weather and radar data. We categorize forecasts as low, medium, or high based on historic data (weather variables and bird migration amounts from radar) for the selected location. A forecast triggers an alert whenever a prediction falls within the “high” category. We base these predictions on numbers of birds/km occurring over a particular area three hours after sunset. Previous research highlights this temporal window as correlating closely with the magnitude of migration throughout the night. We convert this raw prediction into a prediction for an entire night using a multiplier that has been customized for this region based on historic data.