Corn earworm migration potential remains a concern for portions of the corn-growing region especially for the next three nights. A cold front is predicted to push southeast from the northern Plains and upper Midwest into the corn-growing region. With high pressure perched over the Tennessee River valley and southeast United States, south to southwest winds between the high and front may lead to at least scattered corn earworm flights especially with expected precipitation along/south of the front serving as potential insect drop zone regions. The initial Moderate risk area tonight into early Wednesday morning is from Kansas and northwest Missouri north into southeast South Dakota and southwest Minnesota with lesser risks to the north and east. The Moderate risk region shifts southeast with the cold front Wednesday night into Thursday morning and includes northeast Kansas, far southeast Nebraska, northern Missouri, southern/eastern Iowa, and western Illinois. Low risks extend further north into Iowa, southern Wisconsin, southwest Michigan, and Indiana.
Looking ahead to the extended period, the cold front should continue to slowly press south. By Thursday night, the primary risk area shifts into Missouri, central/southern Illinois, and western Indiana with lower risks potentially as far east as Ohio. No risk is predicted Friday night into Saturday morning as high pressure briefly drops into the corn-growing region and greatly reduces any southerly wind flow. Already by Saturday night, however, southerly winds should be back in the Plains as the next weather system approaches so a Low risk is introduced at that time.