"Thunderstorms in a Box": Using the UW-NMS and VIS5D to aid students in the understanding of supercell thunderstorms

In the mesoscale meteorology course, at the University of Wisconsin-Madison, students are challenged to apply their classroom knowledge in a lab exercise referred to as “Thunderstorms in a Box”. Over the years this lab has grown into a multifaceted critical thinking exercise, as well as a department tradition. Students work in teams during this lab exercise. The first component of this lab requires each group to create a sounding they feel is “ideal” for creating a supercell thunderstorm. The sounding may not be from an actual event. Students use a computer script which calculates things such as CAPE, HEL, CIN, LI, BRN, etc., in combination with hodograph and skew-t plots, to develop their “ideal” sounding. Each groups sounding is then used to initialize a UW-NMS simulation. Each simulation receives the same forcing, which is in the form of a heat source at the center of the grid, for approximately the first 20 minutes of the simulation. The output from the simulations is made into VIS5D files. The next component of this lab requires each group to create their own supercell index. Students determine what factors they feel are important in supercell development, and then must apply a quantitative weight to these factors. The only requirements on their index are that it has a quantitative scale and is easily applicable to the information typically found on a atmospheric sounding. Once each group develops their index, they make a formal presentation to the class about their index, and then test their index by applying it to all of the other groups soundings. The culmination of this lab is when the class gets to see the VIS5D animations of the “thunderstorms in a box”. Before showing the animation for a particular group, members of that group explain how features in their sounding are conducive to supercell development. The other groups provide input as to how they think the sounding will work based on how the sounding performed with their supercell index. The VIS5D animations further the learning experience immensely. The three dimensionality of supercell thunderstorms often makes them difficult to conceptualize. VIS5D allows us to show the supercell thunderstorms in three dimensions as well as their development over time. The students enjoy being able to see their “thunderstorm” in 3-D as well as the feeling that they created something. This lab exercise has become so popular that students from past years will attend class on the day the VIS5D animations are shown. This lab is beneficial not only for what students learn about supercell thunderstorms, it also challenges students to apply classroom knowledge, work in groups, and think critically.