Flaring Rates and the Evolution of Sunspot Groups

Solar flares are known to originate in sunspot groups, with increasingly complex magnetic structure leading to more frequent occurrence and often larger magnitude flares. Previously, McIntosh white-light classifications of sunspot groups and their historical flare rates have been used to calculate Poisson probabilities for flare forecasting. Here, we examine the temporal evolution of McIntosh classifications and calculate average flare rates for the following 24-hour periods. The impact that these evolution-dependent flare rates have on the performance of flare forecasts will be presented.