DEVELOPMENT OF THRESHOLD VALUES FOR THUNDERSTORM INDICES OVER KANO, NIGERIA.

Abstract

This research provides the thresholds for thunderstorm indices and non-occurrence of thunderstorm for Kano as well as thunderstorm frequency. Daily Upper air and thunderstorm data for 2011 to 2013 were obtained from Nigerian Meteorological Agency (NIMET), Oshodi to calculate these thresholds. Simple empirical approach was adopted in this research work. Data collected were subjected to quantitative analysis in other to develop probable thresholds for thunderstorm occurrence that is practicable and usable to aviation industry and agriculture in Kano. An Interactive Tephigram Software was used to plot and analyse the sounding observations. The software was made available by University Corporation for Atmospheric Research (UCAR), Colorado, US. The thresholds for each index were obtained for Kano. Result of the calculated thresholds indices such as; Total Total (TT), Lifted Index (LI), Severe Weather Threat (SWEAT) and Convective Available Potential Energy (CAPE) shows little difference from the existing thresholds while K- Index thresholds is exact with the existing thresholds. The frequency of thunderstorm occurrence in the year investigated at Kano shows that thunderstorm is always at maximum during the months of July, August and September and there also could be possibility of dry thunderstorms during some dry months such as April. Disasters associated with thunderstorms are quite dangerous, and this necessitates the need for more accuracy in thunderstorm prediction and forecasts. Though the thresholds derived in this study only show marginal departure from the existing thresholds, it still suggests the need for each station to develop their thresholds to ensure accuracy in thunderstorm prediction and study.