Quantifying Extratropical Transitions of West Pacific Typhoons in the OPC Domain

Typhoons constitute a significant threat to maritime activities and coastal communities, especially when they recurve and transition into powerful extratropical storms. While most tropical threats remain distant from the OPC domain, the trajectory of recurving typhoons places them squarely within the area of forecast responsibility, necessitating a comprehensive study of their behavior and impact to build our own expertise. Understanding the changing characteristics of these storms as they transition is crucial for accurate hazard assessment and response. A case in point is Typhoon Merbok (2022), which evolved into a powerful extratropical cyclone in the northern Pacific, posing dangers to both mariners and Alaska's coastal communities.

In this research, we present an examination of the frequency of recurving typhoons affecting the OPC domain. Leveraging the best track data from the Japan Meteorological Agency dating back to 1951, our study investigates the historical patterns of typhoons that transitioned into the OPC's jurisdiction. By analyzing the dataset of prior storms, we aim to provide valuable insights into the frequency, characteristics, and impacts of these transitioning storms. This dataset combined with our own records of powerful extratropical storms could potentially extend the track data associated with former typhoons. This research not only enhances our understanding of the risks posed by recurving typhoons but also equips the OPC with essential knowledge for improved decision-making, safeguarding maritime operations and coastal communities.