A Multifaceted Review of the East Central Florida Tornado Outbreak of 22-23 February 1998


David W. Sharp, Scott M. Spratt, Bartlett C. Hagemeyer, and Anthony Cristaldi
National Weather Service - 421 Croton Road, Melbourne, FL 32935
mailto:scott.spratt@noaa.gov-david.sharp@noaa.gov
TEL (407) 254 6083 FAX (407) 255 0791

During the late night and early morning hours of 22-23 February 1998, a family of supercells produced four long-tracked F2-F3 tornadoes across the east central Florida peninsula. A total of 42 fatalities resulted, the large majority of whom were killed while asleep in mobile homes. While outbreaks of strong to violent tornadoes have been documented a few times in central Florida over the past 100 years, the high death toll of the most recent event was unprecedented.

This poster will examine several aspects of the outbreak, beginning with a review of previous local research concerning favorable outbreak conditions and the link between El Nino and extreme tornado outbreaks. These studies were used well ahead of the event to inform the public and emergency management community of the greater than normal threat for significant Winter and Spring tornado outbreaks, and to posture the local NWS staff for such occurrences.

NWS Melbourne forecasters had access to a multitude of data from radar and lightning workstations in real-time throughout the event, enabling a complete assessment of the individual supercells. Radar reflectivity and velocity images during various stages of tornadogenesis will be illustrated and compared to concurrent damage pictures. Trends of mesocyclone and tornado vortex parameters will be shown in relationship to tornado occurrence and parent circulation occlusion cycles. The accuracy of the National Severe Storms Laboratory (NSSL) Warning Decision Support System (WDSS) algorithms will be evaluated, specifically the Tornado Vortex Algorithm (TVA), which will become available on the WSR-88D Principal User Processor (PUP) workstation during the Summer of 1998. Unique Total Lightning Information (TLI) signatures will help illustrate the horizontal, vertical, and temporal nature of the electrical discharges associated with the tornado-producing cells. For example, extreme TLI rates of 400+ discharges per minute will be shown to correlate with tornadic cells.

Detailed maps of the supercell and tornado paths will also be shown, along with vital statistics and damage photographs. Finally, a series of NWS products issued prior to and during the most deadly tornado will emphasize the unusually damaging and potentially life-threatening nature of the storm.