Evaluation of Planetary Boundary Layer Schemes during the Lake-Effect Electrification (LEE) Project 18-19 November 2022 Event Using the Weather Research and Forecasting – ELEC Model

Lake-effect storms can be challenging to forecast and can quickly produce hazardous conditions over densely populated areas (e.g., Buffalo, NY blizzard disaster Christmas 2022). Lightning is associated with the most intense lake-effect storms, particularly downwind of the Great Lakes of Erie and Ontario. This study utilizes the Weather Research and Forecasting (WRF) model, with an extra electrification (ELEC) package, to thoroughly analyze the impressive lake-effect storm structure before and during the second intensive observation period of the Lake-Effect Electrification (LEE) project that occurred on 18-19 November 2022, east of Lake Ontario near the Tug Hill Plateau. Previous studies have shown greater planetary boundary layer (PBL) height is critical in initiating lightning in lake-effect storms.

Three model runs were conducted from 0Z 17 Nov to 12Z 19 Nov using the Yonsei University (YSU), University of Washington (UW), and Mellor-Yamada Nakanishi and Niino Level 2.5 (MYNN2) PBL schemes. The convection-permitting WRF simulations, with a 3 km horizontal resolution inner nest, were driven by ERA5 reanalysis data. Project soundings (including electric field meters) and NEXRAD data from the event were used to verify the simulated results. Additionally, the simulated electric field magnitude and flash initiation points were used to assess the location of enhanced electrification and lake-effect lightning in the precipitation band, with each flash compared to lightning mapping array (LMA) data of observed lightning. All model runs were able to reasonably reproduce the electric field magnitude within the lake-effect bands with values greater than 100 kV/m, especially near high reflectivity convective cells. During the period analyzed (18-19 Nov), 27 flashes were recorded by the LMA, while the WRF run with the YSU PBL scheme only produced 2 flashes, UW run produced 0 flashes, and MYNN2 run produced 15 flashes over the LEE domain. No model flashes were produced after 16Z on 18 Nov, however 9 flashes were observed by the LMA from 16Z 18 Nov to 12Z 19 Nov.