Authors: Suma Bhanu Battula – UCSD Scripps Institute of Oceanography
Title: Forecast Uncertainty in Extreme Precipitation Caused by an Atmospheric River and Mesoscale Convective Systems over the Southeastern United States in March 2021
Presentation Type: Poster
Abstract: Atmospheric Rivers (ARs) over the Southeast United States (SEUS) often accompany midlatitude cyclones that transport moisture from lower latitudes over the Gulf of Mexico sometimes referred to as the Maya Express. Analyses of ARs in this region also indicate that they may occur coincident with Mesoscale Convective Systems (MCS) in the region of an enhanced low-level jet stream and moisture to produce extreme precipitation (e.g., Battula et al., 2025, Moore et al., 2012 and O’Brien et al., 2024). An extreme precipitation event featuring an AR and MCS that occurred on 27-28 March 2021 over Tennessee is analyzed. The event produced ~100 mm (~4 in.) of rainfall at Nashville International Airport (BNA) during the three-hour period between 10 PM CDT 27 March 2021 and 1 AM CDT 28 March 2021. This period of intense rainfall occurred in association with Integrated Water Vapor (IWV) values > 40 mm and Integrated Vapor Transport (IVT) magnitudes > 1000 kg m−1 s−1 over western Tennessee. This presentation will focus on the sources of model precipitation forecast uncertainty in the 27-28 March 2021 AR-MCS event.