The method of calculation of power transfer capabilities based on scenario-specific conditions has been used extensively in the transmission system planning and appraisal function, and has proven very useful in the determination of transmission system strength. As an extension of this method, a linear technique called Probabilistic Transfer Capability (PTC) has been developed at the American Electric Power (AEP) Service Corporation for system planning applications. The intent of this technique is to enhance these scenario-specific calculations to capture the variability of transfer capabilities that results from the changing power flows on transmission facilities in actual conditions. With probability distributions of selected generator output, load levels and intersystem transfer levels as input, a probability distribution of real power loading on a facility that limits transfers can be developed. A probability distribution of transfer capability can then be developpd directly from this distribution of facility loading. In addition to assessments of power transfer capabilities, other analyses of steady-state facility loadings are possible using this technique.