A Climatology of Atmospheric Rivers over the Northeast United States
Mentor 1
Clark Evans
Start Date
1-5-2020 12:00 AM
Description
Atmospheric Rivers (ARs) are characterized by long, narrow corridors of enhanced integrated water vapor (IWV) and integrated vapor transport (IVT) located in the warm sector of midlatitude extratropical cyclones. ARs are well-known contributors to high-impact precipitation and precipitation-related events (e.g., floods, landslides, avalanches, etc) and water resources across the western United States. Recent research has also demonstrated that ~40% of southeast U.S. heavy precipitation events in the winter and the transition seasons occur in association with ARs, AR-like, or AR-related features.The goal of this research was to develop a complementary climatology of ARs over the northeast U.S. from 38–48N and 80–66W every six hours for the years 1988–2017 and apply those results to different occurrences of high-impact weather. While many objective algorithms have recently been developed to automatically identify corridors of IWV and IVT resembling ARs, herein we seek to subjectively identify ARs using objective criteria (e.g., an IVT magnitude >250 kg m–1s–1that is >2000 km in length and <1000 km wide or an aspect ratio of ~2:1, and linked to an extratropical cyclone). This presentation will review the results of the climatology summarizing the >3000 ARs identified (~101 per year) over the NEUS. The ARs are approximately evenly distributed throughout the year, with an average duration over the domain of 43 hours, average direction of southwest, and an average maximum IVT magnitude of 737 kg m–1s–1.
A Climatology of Atmospheric Rivers over the Northeast United States
Atmospheric Rivers (ARs) are characterized by long, narrow corridors of enhanced integrated water vapor (IWV) and integrated vapor transport (IVT) located in the warm sector of midlatitude extratropical cyclones. ARs are well-known contributors to high-impact precipitation and precipitation-related events (e.g., floods, landslides, avalanches, etc) and water resources across the western United States. Recent research has also demonstrated that ~40% of southeast U.S. heavy precipitation events in the winter and the transition seasons occur in association with ARs, AR-like, or AR-related features.The goal of this research was to develop a complementary climatology of ARs over the northeast U.S. from 38–48N and 80–66W every six hours for the years 1988–2017 and apply those results to different occurrences of high-impact weather. While many objective algorithms have recently been developed to automatically identify corridors of IWV and IVT resembling ARs, herein we seek to subjectively identify ARs using objective criteria (e.g., an IVT magnitude >250 kg m–1s–1that is >2000 km in length and <1000 km wide or an aspect ratio of>~2:1, and linked to an extratropical cyclone). This presentation will review the results of the climatology summarizing the >3000 ARs identified (~101 per year) over the NEUS. The ARs are approximately evenly distributed throughout the year, with an average duration over the domain of 43 hours, average direction of southwest, and an average maximum IVT magnitude of 737 kg m–1s–1.
