Recent changes in the accounting profession require students to enter the workforce with technical and critical-thinking skills using large datasets. In an audit setting, an important skill is the ability to identify anomalies and risk factors in the client's data. This instructional case provides students with experience using visualization to identify anomalous transactions for further substantive testing based on relationships between financial data (revenues) and nonfinancial data (weather patterns). Students must also create a memo for the workpaper files that documents their findings, including recommendations for the audit team to select specific sales transactions for substantive testing. Aside from gaining experience with Tableau visualization software, this case will improve students' problem-solving and analytical skills by encouraging them to work independently and to break a complex problem into manageable pieces. This case is most applicable for implementation in undergraduate or graduate auditing or internal auditing courses.