NORMAN — Recently, I sat down with David Andra, Scott Curl and Chris Sohl, three meteorologists at the National Weather Service’s Norman forecast office who were among those working during the tornado outbreak May 3, 1999. I asked them what were the differences in technology from when you started at the weather service until May 3, 1999? What helped you do your job that day?
A new systemAndra, the science and operations officer, marks 22 years at the weather service next month. "There were two critical pieces of technology developed between when I started and May 3, 1999,” he said. One was the Doppler radar, installed across the nation by the National Weather Service in the 1980s and early 1990s. Second, the Advanced Weather Interactive Processing System, which processes virtually all information they use in making forecasting and warning decisions. The really interesting part is that this system was introduced into the Norman office in late 1997, so they were still "working out the bugs.” One of those "bugs” was a problem of keeping radar information fresh, Andra said. It wasn’t updating as quick as it should have. "So we did a lot of work with developers in the days leading up to May 3 to fix those things not knowing what was just ahead,” Andra said. "Everything worked very well that day. Everything worked as it should.” Not only quality but quantity was an issue.
Gained on a DAREAndra said that before the Advanced Weather Interactive Processing System, or AWIPS, the Norman office had one workstation. That would have made things difficult on May 3, 1999, with dozens of tornadoes. Instead, there were six stations, and four were dedicated to warnings. Curl was working one of those stations. When he started at the Norman office in 1993, the staff was working on a system that had separate monitors for information. But then came the Denver AWIPS Risk Reduction and Requirement Evaluation, referred to by meteorologists simply as DARE. "We were involved in a lot of DARE testing, which set the ground for the AWIPS,” Curl said. That’s not uncommon. Curl said working in the Norman office often allows meteorologists exposure to new technology and input, as well. "The AWIPS is a lot quicker and more efficiently gives us more lead time,” he said. "It was probably vitally important on May 3, 1999, with the number of tornadoes. "It gives you an advantage down the road, because living in the Southern Plains, it’s just a matter of time before another major event.”
The differenceThere’s a narrow window where conditions come together for a long-track, violent tornado, Andra said. So the system used by staff members lets them look at subtle changes that can contribute to a major event. "For instance, every hour, it runs models that gives us a forecast for the next eight hours,” he said. "That forecast even shows what the radar will look like at that time.” That’s quite a difference from the teletype Sohl used for warnings as a weather service intern in 1981 at Sioux Falls, S.D. A witness to several advances through various systems, Sohl agrees DARE gave meteorologists the technological experience that helped when they went to AWIPS. That, in turn, helped on May 3, 1999, when one storm after another produced tornadoes. "Had we not had that type of technology,” Sohl said, "it would have been very difficult to keep up with that number of tornadoes.”
IF YOU GOAnniversary event When: 8 a.m. to 5 p.m. Friday Where: National Weather Center, Norman
About the eventAn event will commemorate the 10-year anniversary of the May 3-4, 1999, tornado outbreak. There will be sessions focusing on:
• Science and technology
• Emergency preparedness and recovery
• Community and societal impacts
• Individual impacts: The people speak
registrationAttendance is free, but registration is required by Wednesday. A box lunch may be purchased for $10. Online registration and the conference agenda are available at www.srh.noaa.gov/oun/wxevents/19990503/anniversary.php.