For predictions of severe weather or for reports and maps of severe weather that has occurred, visit the National Weather Service/Storm Prediction Center online at http://www.spc.noaa.gov/. The Storm Prediction Center’s daily storm-report maps and notes are available online at http://www.spc.noaa.gov/climo/online/. From that link, you can also access the Center’s archive of maps and reports going back several years. As an example, shown below is the storm report maps for November 29, 2016, when numerous tornadoes and other severe weather were reported in several midwestern, and southern states. Please note that the daily report maps are considered “preliminary” until the reports can be verified later.
The Storm Prediction Center site also has several forecast products, including weather watches/warnings and fire outlooks. Those products are available at http://www.spc.noaa.gov/products/.