The deregulation of the Electricity Sector in US has led to a tremendous increase in the inter-regional wholesale electricity trade between neighboring utilities or regions. For instance, the generation deficit regions may choose to import power from surplus regions; thus the wholesale electricity market prices in the regions are also affected by the dynamics of its electricity trade with other regions. Valuable insights into such imports/exports ahead of time have become crucial market intelligence for the various academicians and the market players associated with the industry. In this thesis, the task of short-term forecasting of the power flows over three major transmission interties of the Pacific Northwest region, namely the Pacific AC Intertie, the Pacific DC Intertie and the Northern Intertie, is successfully accomplished. The Pacific AC and the Pacific DC interties connect the Pacific Northwest region of US with the state of California. The Northern Intertie is the only intertie connecting the British Columbia region in Canada with the Pacific Northwest US. Box-Jenkins ARIMA (Auto Regressive Integrated Moving Average) and Transfer function methodologies are used as the statistical tools to identify the forecasting models in this thesis. The data requirement for all of the models is restricted to publicly available data. / Master of Science