Terminal aerodrome forecasts, simply known to pilots as “TAFs” represent one of the most detailed forecasts made available to pilots. Scheduled TAFs are a textual product issued by meteorologists at the NWS every six (6) hours for 625 airports throughout the United States and its territories and represents an hour-by-hour forecast of the expected meteorological conditions significant to aviation at an airport for a specified period, ordinarily 24 hours. Of course, after the scheduled TAF is issued, the forecaster’s job doesn’t end. They must keep a careful watch on any changing meteorological conditions and issue amendments as necessary to ensure the highest quality forecast. In this workshop, we’ll examine the criteria used by forecasters to see what conditions may trigger an amendment to the TAF.