Atmospheric River Reconnaissance - An Overview of Activities During Water Year 2024

Since 2016, Atmospheric River Reconnaissance (AR Recon) has strived to fill an observational gap over the Northeast Pacific by collecting unique observations during the wet season (November – March). This interagency, international Research and Operations Partnership (RAOP) aims to improve AR landfall forecasts and their associated impacts over the U.S. West Coast and downstream. AR Recon utilizes research aircraft from the U.S. Air Force Reserve Command 53rd Weather Reconnaissance Squadron and the NOAA Aircraft Operations Center to deploy dropsondes which gather vertical profiles of the atmosphere in targeted regions. The aircraft are also equipped with Airborne Radio Occultation (ARO) equipment that collect tangential moisture profiles of the atmosphere. Custom tracks are designed for each flight based on forecasts of essential atmospheric structures and areas of high forecast sensitivity. In addition to AR Recon flights, drifting buoys and profiling floats are deployed over the North Pacific, and radiosondes are deployed from several sites across the western U.S. This collection of unique observations has increased our fundamental understanding of atmospheric rivers, and its assimilation into global numerical weather prediction models has shown positive impacts on forecast.

During water year 2024, over 1400 dropsondes were released and over 3000 ARO profiles were observed during 57 flights over 40 intensive observing periods (IOP), all of which were new record highs for AR Recon. A record number of drifting buoys were also deployed over the North Pacific, including near Guam, a new region for AR Recon. Over land, more than 350 radiosondes were released from five locations in California and one in Washington during high-impact AR events. This presentation will provide an overview of all of the observations gathered during AR Recon 2024 with a unique in depth look at the events sampled and the data collected. Unique features and atmospheric phenomena sampled within these systems will be investigated and discussed. It will also highlight new milestones achieved this year, including the expansion of AR Recon beyond the Northeast Pacific basin and the implications this has on future campaigns.