Implications Involving the Issuance of Public Lightning Advisories for Florida


David W. Sharp
National Weather Service - 421 Croton Rd, Melbourne, FL 32935
david.sharp@noaa.gov TEL (407) 255-0212 FAX (407) 255-0791


In recent years, advancements in mesoscale concepts and associated technologies have greatly improved the anticipation and detection of severe convective storms over Florida. Adhering to traditional definitions regarding life-threatening thunderstorms, the greatest threat to life is from strong and violent tornadoes with a seasonal peak in the late winter and early spring. However, statistics have shown that for any given year in Florida more casualties are typically realized from lightning strikes than from tornadoes (except during significant tornado outbreak years) with a seasonal peak during the summer months. Except for lightning education and preparedness efforts, very little has been done to operationally address the threat of lightning to the public at large.

In an attempt to satisfy the agency mission towards the protection of life and property, the National Weather Service in Melbourne, FL (NWS MLB) has instituted a total lightning information (TLI) initiative. At the heart of this initiative is the real-time access to both cloud-to-ground (CG) strike data (through the National Lightning and Detection Network) and 3-D volumetric total signal data (through the Lightning Detection and Ranging (LDAR) network located at the Kennedy Space Center). During the summer of 1997, NWS MLB began intently including lightning information into public products. Climatological, statistical, and safety information was included in the morning Hazardous Weather Outlook (HWO) product according to the current synoptic and mesoscale weather pattern. The HWO is intended for planning purposes and was used to describe the geographical distribution and timing of the onset and ending of deadly CG lightning strikes. Particular attention was given to lightning sensitive situations where large numbers of people were expected to be outdoors away from ready cover. This would include the central Florida attractions, the beaches (such as Daytona Beach and Cocoa Beach), major golf courses, and the marine community.

As each convective event unfolded, lightning information was routinely included in the Nowcast product. LDAR information was used to detect early signs of electrical activity aloft over generalized areas before actual CG strikes occurred. The term "lightning storm" was used when the predominate threat was considered to be lightning (and not tornadoes, damaging wind, or large hail). Preliminary quantitative descriptor definitions of CG discharge frequency were used to include "excessive", "frequent" and "occasional". By the end of the season, a somewhat awkward but promising success was achieved. In November 1997, the NWS Southern Region legitimized the MLB initiative by endorsing project ELISE (Enhanced Lightning Information and Services Experiment). This project put forth five specific lightning-related objectives among which were the inclusion of lightning information in public products as well as the issuance of experimental public lightning advisories for individual counties. This paper will address the resultant implications of the NWS MLB initiative and subsequent implications as experienced during ELISE when issuing such advisories.