Lightning? Above 70 Degrees North? It's More Likely Than You Think: A Comparison of Two High-Latitude Thunderstorm Outbreaks

Thunderstorms are considered to be typical features of midlatitude and tropical meteorology, but can also occur at high latitudes. Due to both their latitude and the fact that they occur in largely unpopulated areas, satellite observations are limited and radar and in-situ observations are practically nonexistent. Lightning from these storms is the primary cause of wildfire activity in this region. Two of these outbreaks on record include an outbreak in the Canadian Arctic in July of 2014 and an outbreak in northwest Alaska in June of 2024. The 2014 outbreak was previously studied by Brown et al. (2020), but with less of an emphasis on the synoptic-scale contributors to the conditions observed and with a different lightning data source. Reanalysis, model initialization fields, and trajectory models were used to identify if the two storms had similar synoptic-scale features, such as an omega block and comparing parameters used to evaluate midlatitude convection. Both cases had an omega block pattern present, with dew point temperatures as high as 20° C and lifted indices as low as -6° C observed during the outbreak, both of which are consistent with midlatitude convection. Recent studies suggest that thunderstorm outbreaks at these latitudes may become more frequent as the climate continues to change, so it is important to understand thunderstorm climatology at high latitudes, and identify key synoptic factors for their development in comparison to midlatitudes.