BOULDER--Tornado-bearing thunderstorms raced across centralAlabama just after dark on April 8. In their wake, 34 people died,with several other deaths reported in Mississippi and Georgia.Tragic as it was, the high death toll wasn't for lack of officialnotice. Tornado watches were issued hours before the twistersstruck, and 36 warnings from the National Weather Service (NWS) inBirmingham, Alabama, gave residents an average of 13 minutes toseek shelter.
Over the past year, forecasters in Birmingham and in Melbourne,Florida--where twisters killed 42 people in February--have honed theirstorm-prediction skills with two training modules on CD-ROM:Anticipating Convective Storm Structure and Evolution and AConvective Storm Matrix: Buoyancy/Shear Dependencies. Both moduleswere prepared by the Cooperative Program for Operational Meteorology,Education and Training (COMET) of the University Corporation forAtmospheric Research (UCAR).
The two modules combine storm theory, observations, and computermodels to help users peg storm types in advance when they know agiven day's blend of ingredients--in particular, buoyancy(instability fueled by warm, moist surface air) and shear (windsthat strengthen and/or veer with height). The modules wereprepared with the assistance of Morris Weisman, a meteorologist atthe National Center for Atmospheric Research (NCAR). NCAR isoperated by UCAR under sponsorship of the National ScienceFoundation.
"I can't give the modules high enough praise, especially the twoconvective modules. Both of them are very useful," says KevinPence, science and operations officer at the Birmingham NWSoffice. As the wind shear above Birmingham evolved on April 8 intoa classic tornado-producing pattern, "The conceptual modelsstressed by the modules were certainly being knocked around theoffice," Pence adds.
Recognizing the Florida weather threat of February 22-23 wellahead of time, the Melbourne forecasters alerted the public to thesevere potential 36 hours before the deadly outbreak. "The patternwas a classic severe weather set-up, just like you see in themodules and the textbooks," says Melbourne forecaster TonyCristaldi. He calls the COMET modules "an excellent extension ofthe [other] training we receive."
Through residence courses and distance learning, the COMET Programtrains meteorologists at weather services, the U.S. armed forces,and universities throughout the world. It is sponsored by the NWS,the Air Force Weather Agency, and the Naval Meteorology andOceanography Command. The program is in the midst of a multiyeareffort to train the nation's forecasters in how to anticipatethunderstorm hazards. The emphasis was first on single storms. Nowthe focus is broadening to mesoscale convective systems (MCSs),clusters of storms that have their own hazardous qualities.
Since the 1980s, a group of NCAR meteorologists, includingWeisman, has forged a body of theory on storm behavior based onthe interplay between buoyancy and shear. With Weisman's help, theCOMET Program's modules convey the group's work in a three-dimensional, animated format. "Who needs another textbook? We aretrying to take a step beyond that to a new level of education,"says Weisman. The Convective Storm Matrix includes up to 54simulated combinations of buoyancy and shear and depicts the kindsof storms one could expect in each situation.
"We've really been pushing the envelope in visualizations," saysWendy Abshire, a COMET meteorologist. COMET visual artists havecreated more than 10,000 stills and animations for the program's18 modules to date.
This year COMET is developing a set of new modules that show notjust how a single storm grows and dies, but how groups of stormsinteract with each other and behave as an MCS. Two of the new MCSmodules are now available on theWorld Wide Web, the first time COMET has placed itsmodules on the Internet. Aimed at the university community, thesemodules can be accessed by any user whose Web domain name ends in".edu." To create the MCS modules, Weisman teamed with fellow MCSexpert Ron Przybylinski (NWS/St. Louis).
The on-line MCS modules feature a wealth of color imagery:downdrafts and updrafts, vortices forming at the ends of squalllines, supercells evolving into bow echoes, lines evolving intocircular masses. The module developers expect serious users tohave an upper-division undergraduate or beginning-graduatebackground. However, site visitors don't need a technicalbackground to admire the beauty of the animations and learn somebasic concepts.
Writer: Bob Henson
Note to Editors: Several color illustrations from storm-relatedCOMET modules are available for use in stories covering COMETactivities. These images may be obtained electronically from UCARCommunications, 303-497-8607, [email protected]
Find this news release on the World Wide Web athttp://www.ucar.edu/publications/newsreleases/1998/comet.html
To receive UCAR and NCAR press releases by e-mail,telephone 303-497-8601 or e-mail [email protected]
The above story is based on materials provided by University Corporation For Atmospheric Research. Note: Materials may be edited for content and length.
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