The Nexus Between Convective Allowing Modeling and Outreach in Facilitating Decision Making for High Impact Events in the North American Monsoon.

The North American Monsoon is a critical, yet highly variable (both spatially and temporally) component of the climate of the Southwestern United States. The variability of the Monsoon has been particularly evident since 2020, with each of the last 4 seasons lying at the tail ends of the climatological distribution (2020 and 2023 hot/dry; 2021 and 2022 cool/wet). The importance of the Monsoon in the hydrological cycle of southern Arizona in combination with its variability creates a unique challenge for stakeholders in the Southwest, including utilities, flood control districts, and the National Weather Service. This has led to the rise of the Center of Applied Hydroclimate Science which incorporates several entities across the University of Arizona to provide better hydroclimate predictions and projections to help leverage better decision making and science translation for stakeholders. Efforts within the Department of Hydrology and Atmospheric Science included the development of a parameterization of the University of Arizona WRF (UA WRF) model, run with the same initial conditions as the High-Resolution Rapid Refresh Model (HRRR) which has been online since July 11, 2022. The preliminary results based on the categorical statistical analyses demonstrated an increase in precipitation forecast skill for the 2022 Monsoon season in the HRRR parameterized UA WRF model relative to model forcing as well as a clear forecast improvement relative to forcing parameters derived from coarser resolution initializations such as the Global Forecast System (GFS). For the 2023 Monsoon Season, this model was used as the basis for a daily blog of detailed forecast discussions focused on providing value added information for stakeholders on high impact weather events focused on heat, wind, and rain. As part of this ongoing effort a new website is being developed in collaboration with stakeholders to provide forecast products that are tailored to the specific needs of utilities and flood control districts.