Extended Abstract (1.6M)1.1
Operational Applications of Lightning Data at WFO Melbourne, FL: A 15-Year Retrospective
David W. Sharp, NOAA/NWS, Melbourne, FL
In the fall of 1989, the National Weather Service (NWS) opened their first modernized Weather Forecast Office (WFO) with a commitment to operationally employ state-of-the-science weather observation information. The office was strategically located at Melbourne in central Florida, a region where the occurrence of lightning is greater than anywhere else in the country. Both climatologically and statistically, lightning has repeatedly proven itself to be a prime hazard here, often resulting in more casualties and property damage on an annual basis than other weather-related hazards. Thus, from the earliest days, WFO Melbourne engaged in local applied research and scientific community collaborations to find ways to mitigate the effects of lightning and to tend toward the eventual issuance of public watches and warnings. Importantly, the NWS is now acquiring the necessary momentum to reach this critical milestone operationally. As we prepare for this exciting phase, it is appropriate to review at least one avenue which brought us to this point. This paper endeavors to provide a 15-year retrospective of operational applications of lightning data at WFO Melbourne. The paper will establish initial experiences using real-time cloud-to-ground (CG) data through automated dial-up connections and WFO-modified display software. Courtesy access was granted to the Lightning Position and tracking System (LPATS), which utilized the time of arrival technique for locating strikes. Eventually, LPATS would be combined with the Lightning Location and Protection (LLP) system to create an impressive national network. Experimentally, lightning information was introduced into WFO products and services. Early applications were modest, helping forecasters to simply distinguish showers from thunderstorms, while augmenting radar data prior to the WSR-88D era.
This paper will continue to trace landmark achievements such as the introduction of total lightning information into the WFO environment. By 1993, WFO Melbourne was given access to the Lightning Detection and Ranging (LDAR) system via the National Aeronautic and Space Administration (NASA) at the Kennedy Space Center (KSC). Developed throughout the 1980s, the system was delivered for operational use in the early 1990s to support the nation’s space program. Here, three dimensional total lightning signals are identified through the depiction of individual point-sources and graphically displayed. This represented a considerable advancement to operations given that the balance of electrical character of a storm was revealed. Learning from lightning safety experts at KSC and from the United States Air Force’s 45th Weather Squadron (45th WS), WFO Melbourne became more proficient in its use, especially for aviation purposes. Lightning alert areas were configured for the Terminal Aerodrome Forecast (TAF) airports located at Orlando, Daytona Beach, Vero Beach, and Melbourne. The intent was to optimize the use of “TS” (thunder) and “VCTS” (vicinity thunder), and to expedite Local Airport Advisories (LAA). More so, since LDAR was used to issue lightning watches and warnings at KSC, strategies for experimental public watches and warnings were outlined. In fact, WFO Melbourne used LDAR to support the 1996 Summer Olympic soccer venue in Orlando as well as other outdoor festivities. With LDAR, the potential for CG discharge is often evident during those critical periods of first and last strikes or when lightning might travel greater distances from the parent storm channeled through charged cloud or cloud debris. Together with teams from Marshall Space Flight Center (MSFC) and Lincoln Laboratories at the Massachusetts Institute of Technology (MIT/LL), innovative research was performed to process point-source information into flashes which were associated with specific convective cells and trended. Parallel concepts for trending total lightning flashes obtained from satellite-based sensors were also pursued. A primary thrust was a search for potential severe thunderstorm and tornado indicators to improve lead-time and verification scores. This effort culminated during the 22-23 February, 1998 killer tornado outbreak across central Florida. Integrated with radar trend information, total lightning trend information was operationally used during the warning-decision process with promising results. Rapid increases in flash activity were correlated with accelerations within updrafts, while dramatic decreases were followed by collapsing weak echo regions and tornado onset. When properly harnessed, LDAR data can aid the forecaster in discerning severe local storms; this is a powerful declaration.
This paper will conclude with an expression of current activities. Also in 1997, the NWS Southern Region endorsed a project which enabled WFO Melbourne to explore the issuance of lightning outlooks and pseudo-warnings through the Enhanced Lightning Information and Services Experiment (ELISE). Consistent terminology was established by which lightning storms may be described within public products. “Excessive Lightning Alerts” (ELA) are now issued for the public whenever a storm’s primary hazard is considered to be lightning and when its CG trend information reveals a rate of twelve flashes per minute averaged over several minutes. Descriptions of onset and cessation may also be included in short-term forecasts. Since that time, procedures and techniques have improved with easy to use templates on AWIPS/WarnGen. Uniquely, results of important research in climatology through Florida State University and Texas A&M University are now used to produce Lightning Threat products in both graphical and gridded form for east central Florida on the Graphical Forecast Editor (GFE). This is done within the Hazardous Weather Outlook (HWO) product. The advent of the experimental Lightning Threat product, along with the ELA product, has helped bring the agency to the threshold of a 15-year vision.
Session 1, Lightning applications in warning and decision support 1: Operational applications
Monday, 10 January 2005, 9:00 AM-10:15 AM
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