This was by far the best day of the 2018 season for me! We chased the front range of Colorado. Akos, Mark, and I watched 3 supercells develop off the range and push east over Denver and the surrounding area. We perched up on a hill and watched the three cells evolve and develop over an hour. It was pretty cool to be surrounded by supercells and have an eye on all of their bases at once. We moved east with them as the pushed out of Denver, and the middle cell got a tornado warning; although, we didn't initially jump on it. We could see all the bases, and we weren't too impressed with the middle one... yet. Eventually, an outflow boundary moved through and undercut the tornado warned cell. However, we noticed that it quickly recovered and began pulling in the boundary. By this point we were sold. We headed straight for it, and a few minutes after we arrived it put down a beautiful, though only 5 minute-long tornado.