A cold front will move through the corn-growing region in the next 72 hours. The front divides south to southwest winds to its east from northwesterly winds to its west, so any corn earworm migration risk will lie to the east of the front. Only low risks are predicted due to the lateness in the season and availability of crops at susceptible stages to damage, but some isolated moth flights may be observed especially in the upper Midwest and Great Lakes region where some fresh market and processing crops may still be present. Low risks are in place tonight into Thursday morning from the eastern Plains east into the southwest Great Lakes region. The risk focuses mainly east of a Des Moines, Iowa to east of Eau Claire, Wisconsin line tomorrow night into Friday morning, and then east of I-57 and Lake Michigan by Friday night into Saturday morning. No risk is predicted thereafter as high pressure moves into the upper Midwest and keeps any southerly winds away from fields that may still be at risk.