Atmospheric River Recon

AR Recon Data

Coordinated University Sounding Program

About AR Recon CUSP

The CW3E Atmospheric River Reconnaissance (AR Recon) Coordinated University Sounding Program (CUSP), led by PI Marty Ralph, is a partnership between CW3E and 15 universities across the U.S. and Canada to collect on-demand observations during active weather events in association with AR Recon. The main function of AR Recon CUSP is to launch weather balloons equipped with high-tech sensors called radiosondes, in coordination with AR Recon missions, to provide broad-coverage observations during atmospheric rivers and other major precipitation events. This university network plays an important role in broadening observational coverage to sample environments upstream, downstream, and within landfalling AR events, measuring pressure, temperature, wind speed and direction, and humidity throughout the atmosphere. These observations are disseminated in real time, improving the accuracy of the forecasts during impactful weather events that communities, emergency managers, and water operators depend on.

AR Recon CUSP is unique in that it is entirely powered by faculty, staff, and student teams at participating universities, providing an experiential learning opportunity for undergraduate and graduate students. Students help lead launch planning, weather balloon deployment, and tracking of radiosonde output through the upper atmosphere. University participants can also join daily AR Recon briefings to learn how science teams across agencies work together in real time to plan missions in response to evolving storm forecasts.

If you are interested in joining the AR Recon CUSP network, please reach out to Allison Michaelis.

AR Recon CUSP is directed by PI Marty Ralph at CW3E with support from the leadership team: Allison Michaelis (Lead Coordinator; North Carolina State University), Anna Wilson (CW3E), Travis O’Brien (Indiana University), and Belay Demoz (University of Maryland Baltimore County).

Partners

The AR Recon CUSP team would like to acknowledge and thank our university partners: Indiana University, McGill University, North Carolina State University, Ohio State University, Oklahoma University, Oregon State University, the Salt River Project and Arizona State University, Texas A&M University, University at Albany, University of British Columbia, University of Maryland Baltimore County and Howard University, University of Missouri, University of North Dakota, Valparaiso University, and Virginia Tech University.

In addition to AR Recon, AR Recon CUSP coordinates with other airborne field campaigns, including the North Atlantic Waveguide, Dry Intrusion, and Downstream Impact Campaign (NAWDIC) and the North American Upstream Feature-Resolving and Tropopause Uncertainty Reconnaissance Experiment (NURTURE), in support of the Global Atmospheric River Reconnaissance Program (GARRP).

Observations

AR Recon CUSP observations are typically collected every three hours beginning at 21 UTC and ending at 03 UTC to coordinate with active AR Recon flights centered at 00 UTC; specialty observations are also collected during additional periods of interest advised by the AR Recon Mission Director in consort with the AR Recon forecast team, NCEP Central Operations, the Weather Prediction Center, or local National Weather Service Weather Forecast Offices. The collected data are sent to the Global Telecommunications System and are available for assimilation into operational global models. During the 2025 AR CUSP season, just under 100 radiosondes were launched across nine participating sites; with the expansion to 15 universities and additional launch days, over 470 radiosondes were launched during the 2026 season.

An archive of AR Recon CUSP collected radiosonde data and images are available online here.

Plot description: The Skew-T Log-P diagram displays temperature (red line, °C) and dew point (blue line, °C) measured by the radiosonde as it ascends through the atmosphere. Observed winds are shown by wind barbs (knots) on the right. Parameters listed at the top calculated via the profile include the Lifting Condensation Level pressure (LCL P) and temperature (LCL T), Showalter Index (SWI), Convective Available Potential Energy (CAPE), Integrated Water Vapor (IWV), Integrated Water Vapor Transport (IVT), and height of the 0°C isotherm. The right plot shows the water vapor flux (g/kg*m/s) observed throughout the atmosphere. For an in-depth explanation of how to read skew-t plots, please see NOAA’s explanation of Skew-T Log-P Diagrams and Skew-T Plots.

Site Status: Active  No launches during 2026  Selected

Funding

The 2026 AR Recon CUSP season was supported by PI Ralph through the CW3E Forecast Informed Reservoir Operations (FIRO) Program with the U.S. Army Corps of Engineers (USACE) Engineering Research and Development Center (ERDC).