This proposal addresses the needs of the Lake Michigan Air Directors Consortium (LADCO), which conducts State Implementation Plan (SIP) air quality assessment modeling for its member states: Illinois, Indiana, Michigan, Ohio, and Wisconsin. SIP modeling is required under the Clean Air Act to demonstrate strategies to mitigate nonattainment of the National Ambient Air Quality Standards associated with ozone exceedances along the Lake Michigan shoreline. We will support LADCO through development, verification, and delivery of a satellite-constrained meteorological modeling platform to conduct air quality assessment modeling for ozone in the Lake Michigan region. Meteorological modeling for this region is challenging due to the influence of mesoscale lake breeze circulations on the transport and chemistry along the Lake Michigan shoreline. The modeling platform will be based on the Weather Research and Forecasting (WRF) model and will include regional nests covering the LADCO states and Lake Michigan with 4- and 1.3-km resolution, respectively. These high-resolution domains will be nested within a continental scale 12-km resolution domain that is similar to that used by the Environmental Protection Agency. Tracking of the observed synoptic evolution within regional downscaling runs will be accomplished through 3-dimensional and surface analysis nudging. Sensitivity experiments will be conducted to determine the optimal configuration for the LADCO meteorological modeling platform. Airborne and