Just the Facts The storm intercept in west Texas on June 2 was a classic example of VORTEX data collection the way it was designed. The VORTEX team was able to document the entire life cycle of a tornado from its development through its rope tornado demise. A mobile X-band scanning Doppler radar collected numerous volume scans of data at a range of 3 km from a tornado near Dimmitt, TX. The tornado debris cloud was obvious in the reflectivity data. Preliminary examination of the Doppler velocity data suggests average winds within the radar beam near the tornado to be nearly 60 m/s (135 mph). Using the VORTEX-designed "mobile mesonets," nearly 1000 automated surface weather observations were collected within a few kilometers of the tornado. Roughly 1000 other observations were obtained in other parts of the tornadic storm, combined with data gathered during several balloon launches. Airborne Doppler radars on the NOAA P-3 and NCAR Electra aircraft thoroughly documented airflow throughout the parent storm. Operations 1994: A near record for fewest number of tornadoes in the VORTEX area. Nevertheless, VORTEX collected data on several supercell thunderstorms, although no tornadoes were intercepted that logistically allowed the mobile mesonet to be deployed. VORTEX operated on 18 days and collected data on storms on 9 days. 1995: VORTEX operated on 18 days, collected data on 13 of those days. A total of 9 tornadoes were intercepted: 17 April (1) near Temple Oklahoma 16 May (3) in southwestern Kansas 2 June (2) at Friona and Dimmitt, Texas 8 June (3) at Wheeler, Allison, and southeast of Allison, Texas The two tornadoes on 2 June and two of the tornadoes on 8 June were large, violent tornadoes. What has been learned? Analysis of VORTEX data will take many years. The "easy" part of the project, collecting the data, is over. Results are beginning to appear in the scientific literature (one paper on the 29 May 1994 Newcastle, Texas tornadic storm has appeared in Monthly Weather Review) and at conferences. Some of these papers are available on the Web. "In general, for the 1995 events, we plan to "pair" a tornadic and non-tornadic storm and put efforts into understanding them. The first pair is the 2 June Dimmitt tornadic storm and the 22 May Shamrock, Texas non-tornadic storm. The second pair is the 8 June Kellerville/Allison tornadic storm and the Elmwood, Oklahoma non-tornadic storm. Some individual aspects of the Dimmitt analysis have been completed, notably the upper air balloon observations, the mobile mesonet surface observations, the DOW, and airborne radar components. Components of other days have also been completed. Attempting to put all the information into a single 4-dimensional package still awaits. We found some surprising results. The Dimmitt tornado formed without a substantial temperature gradient at the ground, as had been hypothesized. The Dimmitt and Newcastle tornadoes also formed extremely rapidly from the beginning of the storm (~30-40 minutes). We also found examples (e.g., 2 June 1995) of extremely large gradients in the low level moisture field, not associated with a dry line, but which might have significant impact on the environment a storm "sees". Data was collected that will address many of the hypotheses proposed in VORTEX. Putting everything together is not a fast process, particularly since we are dealing with new data sources (the mobile mesonet and DOW). However, we are confident that over the next few years, our understanding of tornadic storms will be improved as the result of VORTEX. Already, some new explanations of aspects of tornadic behavior have been proposed. They await testing with theoretical understanding and more VORTEX cases." Harold Brooks VORTEX-95 The data sets obtained by VORTEX are several orders of magnitude richer by comparison than any collected before on a tornadic storm. This information will provide invaluable knowledge to help reduce false alarms, improve predictions of supercell storms, and determine what causes storms to become tornadic. Sub-VORTEX In the spring of 1997, Sub-VORTEX was conducted as an extension of VORTEX. Using the experience gained in '94 and '95, the project was conducted with fewer vehicles and a tighter focus. Sub-VORTEX Interview with Dr. Erik Rasmussen and Dr. Josh Wurman. [text transcript of interview] The VORTEX project will continue as plans for future Sub-VORTEX programs are underway. 5