From: "William T. Reid" <73551.2512@CompuServe.COM> The following is my chase account of May 23, 1996, which was highlighted by the gorgeous low-precipitation supercell near Last Chance, Colorado. The previous day, May 22, was a great chase day for my chase friends and myself, thanks to the tornadic Benkelman, Nebraska, supercell. The weather pattern continued very favorable for severe weather on the High Plains on Thursday, the 23rd, as the trough over the Great Basin was forecast to send more upper-level energy and vorticity into Colorado, Kansas, and Nebraska. I awoke in Oberlin, Kansas, and headed to the National Weather Service in Goodland for some weather information. My idea wasn't very original, as the office parking lot was full late that morning! At least eight other chase teams, including Roger Edwards, the Verkaiks, Tim Samaras and Dean Cosgrove were there, as was a "Nightline" TV news crew to document the chase exploits of Daphne and Richard Thompson. The Storm Prediction Center had northern Kansas, southern Nebraska, and extreme eastern Colorado in a moderate risk area for severe weather. Helicities and capes were more than sufficient for supercells and tornadoes. A frontal boundary was oriented about east-west near the KS/NE border and extended westward into Colorado. Convergence was excellent along the front, so the only question was: "Where along this boundary should we hang out?" I felt that the first storms to go up would likely be near the front range in Colorado, so we left Goodland and headed west on Interstate 70. Skies were mostly clear as we entered Colorado early in the afternoon, and I was a little concerned that we might be too far south of the boundary. We headed north on 385 at Burlington. It turned out that we were closer than I thought, as we found ourselves under a dense stratus overcast before reaching the next paved road, U.S. 36. We stopped in Cope for gas and a little food, and then found a hill west of town where we were able to pull in NOAA Weather Radio. By this time, about 3 p.m. MDT, a tornado watch had already been issued for much of northeastern Colorado, and the low clouds were breaking up a little and moving in quickly from the east. With no warnings yet and with visibility limited by the low clouds, I had to get back into the clear skies. We tried the dirt road network south of Anton and breezed through Thurman and Shaw. Finally we were able to see what we were looking for, and it was a good one! A large and isolated thunderstorm tower was taking shape directly to our west as we drove the dusty Road 3X through northern Lincoln County. At 5 p.m. we had made it to pavement again, Highway 71, and a tornado warning was issued for the rotating tower about 15 miles to our west. The cell was northwest of Limon, so that put it along Interstate 70 near Agate. It was moving northeast, towards Last Chance. We were in an excellent spot to watch the storm approach and strengthen. The storm's base was rather low to the ground, by Colorado standards, and we could see beneath it. We did not observe any circulations near the ground, but everything else was rotating! The storm's updraft base took on a beautiful and sculpted laminar appearance, with a smooth inflow tail sticking way out to its northeast. The mid and upper levels of the tower were rock hard and showed obvious rotation, but were not smooth and laminar-looking. The updraft was powerful and magnificent, with a strong and hard back-sheared anvil and wild, inverted cumulus bulging downward infront of it up top. This storm is the most beautifu low-precipitation supercell I have ever seen. We watched the storm drift over an area with no roads to our northwest from Highway 71, near the Lincoln and Washington county line. We had inflow winds of about 20 knots, and the eastern edge of the base was encroaching. Lightning started to shoot down out of the anvil to our north, and precipitation began to increase from the storm's base. At about 5:45 p.m. another tornado warning was issued, this time for southwest Washington County, and the NWS put the storm 27 miles north of Limon, just to our north. We did not see any tornado, though the area of precipitation was increasing and a rain-wrapped tornado could not be ruled out. Our road options were not good---we could flirt with the core and try our luck with dirt roads south and southeast of Last Chance. (It was obvious that Last Chance and U.S. 36 were a little too far north, and were probably getting the (hail) shaft. This storm was no longer an LP.) Our other option was to head back south about 5 miles to Road 3X, and then go east to keep up with the storm. We played it safe and retreated southward. There was some new development to the south-southwest, so we thought that it might be a good idea to keep an eye on that, too. We stopped and chatted with Bobby Prentice at Road 3X and Highway 71, about halfway between Limon and Last Chance. Our supercell, now to our north-northeast, still looked good up top --- but the lower levels were beginning to lose all definition. It was disappointing to watch such a gorgeous storm get so sloppy looking, as haze and precipitation increased dramatically. Our chase day was coming to an untimely end. We drove south to Limon, but the activity towards our south was not strengthening. Soon we found ourselves in fog and very cool northeasterly winds. We couldn't see a storm, or a tornado, if it was a wheat field away! There was still an hour of daylight left, but we had gloom and doom conditions as we headed back towards Goodland on Interstate 70. Moist air north of the frontal boundary, in combination with outflow from the storm, really put the "slop" into "upslope" this evening! This was one of the strangest chases I've ever had. It was about an hour's worth of watching and worshipping from Highway 71, and then it was over!