Developing empirical lightning cessation forecast guidance for the Cape Canaveral Air Force Station and KennedySpace Center

摘要

[1] This research addresses the 45th Weather Squadron's (45WS) need for improvedguidance regarding lightning cessation at Cape Canaveral Air Force Station and KennedySpace Center (KSC). KSC's Lightning Detection and Ranging (LDAR) network was theprimary observational tool to investigate both cloud-to-ground and intracloud lightning.Five statistical and empirical schemes were created from LDAR, sounding, and radarparameters derived from 116 storms. Four of the five schemes were unsuitable foroperational use since lightning advisories would be canceled prematurely, leading to safetyrisks to personnel. These include a correlation and regression tree analysis, three variantsof multiple linear regression, event time trending, and the time delay between the greatestheight of the maximum dBZ value to the last flash. These schemes failed to adequatelyforecast the maximum interval, the greatest time between any two flashes in the storm.The majority of storms had a maximum interval less than 10 min, which biased theschemes toward small values. Success was achieved with the percentile method (PM) byseparating the maximum interval into percentiles for the 100 dependent storms. PMprovides additional confidence to the 45WS forecasters, and a modified version wasincorporated into their forecast procedures starting in the summer of 2008. This inclusionhas resulted in 5-10 min time savings. Last, an experimental regression variantscheme using non-real-time predictors produced precise results but prematurely endedadvisories. This precision suggests that obtaining these parameters in real time mayprovide useful added information to the PM scheme.