Warm-season precipitation in the United States “Corn belt,” Great Plains and Midwest, greatly influence agricultural production and is subject to seasonal variability.
Warm-season precipitation in the United States “Corn belt,” Great Plains and Midwest, greatly influence agricultural production and is subject to seasonal variability. Current seasonal to subseasonal forecasts for warm-precipitation have relatively low skill. Because of this, there are ongoing efforts to understand the hydroclimate variability of the Great Plains low-level jet (LLJ). The LLJ is a fast-moving current of air, responsible for transporting warm temperatures and Gulf moisture into the region. In a new Weather and Forecasting article, authors Kelsey Malloy and MAPP-funded PI Ben Kirtman, use the Community Climate System Model (version 4) July forecasts, made as part of the North American Multi-Model Ensemble (NMME), to analyze skill in reproducing the Great Plains LLJ and warm precipitation.
It was found that the Community Climate System Model forecasts captured the Great Plains LLJ but had problems representing the observed variability beyond two weeks. In addition, the presence of a strengthened Caribbean LLJ, negative Pacific-North American (PNA) teleconnection, El Niño, and a negative Atlantic Multidecadal Oscillation (AMO), each have a strong and consistent relationship with a strengthened Great Plains LLJ. Though, the Caribbean LLJ and PNA, present the greatest “forecast of opportunity” for considering and assigning confidence in monthly forecasts.
It is noted that future research will need to address the differences between spring and late-summer Great Plains LLJ variability and mechanisms.
The Modeling, Analysis, Predictions, and Projections (MAPP) Program is a competitive research program in NOAA Research’s Climate Program Office. MAPP’s mission is to enhance the Nation’s and NOAA’s capability to understand, predict, and project variability and long-term changes in Earth’s system and mitigate human and economic impacts. To achieve its mission, MAPP supports foundational research, transition of research to applications, and engagement across other parts of NOAA, among partner agencies, and with the external research community. MAPP plays a crucial role in enabling national preparedness for extreme events like drought and longer-term climate changes. For more information, please visit www.cpo.noaa.gov/MAPP.