Development and Evaluation of Operational Lightning Forecasting System based on Lighting Detection Network

 Recently, severe weather such as heavy rainfall, typhoon, hail, and lightning has become more frequent due to climate change. Especially heavy rains and localized precipitation systems accompanied by lightning strikes has not only human casualties but also social and economic impacts. To minimize the damage caused by lighting, research into the causes of lighting and their predictions are necessary.

 Korea Meteorological Administration(KMA) has been operating the Lightning Forecasting model to predict lightning forecast information on the Korean Peninsula. This model uses the energy density of lightning strikes detected by a total of 21 sensors of the LINET(LIghtning NETwork) systems(Nowcast, Germany). The energy density is calculated as the energy per unit area per unit time(kAkm^-2hr^-1) using CC(cloud-to-cloud) and CG(cloud-to-ground) lightning observation. This provides quantitative information on where strong lightning strikes are concentrated. In addition, the vector fields derived by applying the variational Echo Tracking(VET) algorithm are performed on the energy density and these are advected to the entire density field calculated by the semi-Lagrangian backward advection method. Finally, This very short-term quantitative lightning forecast data is produced every 10 minutes up to 6 hours ahead.

 The evaluation of lightning forecasting is performed from 2019 to 2021 based on each month and season which is a total of 192 cases, and regions for the Korean Peninsula. The verification methods range from simple traditional skill scores to methods for quantitative comparison between the prediction model and lightning frequency observation. Based on the results of the evaluation, the record score of the total critical success index(CSI) is 0.48 within 1 hour, autumn is the highest season(0.51), and winter season(January, CSI=0.17) is the lowest(0.17).

 

Acknowledgements:

This research was supported by the ”Development of Integrated radar analysis and customized radar technology (KMA2021-03021)” of “Development of integrated application technology for Korea weather radar” project funded by the Weather Radar Center, Korea Meteorological Administration.