Analysis of the 2023 Low-Latitude Polar Low Using Reanalysis and Radar Observations

Polar Lows (PLs) are small but intense hurricane-like maritime cyclones that form poleward and westward of the primary extratropical cyclone circulation track over the Atlantic and Pacific Arctic regions and Southern Ocean. In 2023, a very unusual Polar Low occurred at 36º latitude near the eastern coast of the United States – the lowest latitude for a recorded PL. Through aircraft radar observations and reanalysis datasets, this study examines the storm’s structure and thermodynamic properties. Trajectory modelling using NOAA’s HYSPLIT reveals air parcel origins and potential mechanisms leading to the formation of the storm. The storm developed along a strong temperature gradient, with heat fluxes from the ocean’s surface destabilizing the atmosphere, resulting in the PL’s development. This behavior was similar to a class of polar lows forming at high latitude that develop as a result of conversion of potential to kinetic energy drawn from the associated temperature gradient. The latent and sensible heat fluxes from the ocean surface provided further energy to maintain the storms over 36 hours as it moved northeast across the Atlantic. This analysis will aid in the understanding of Polar Lows and the unique circumstances causing this unusual storm.