Moderate corn earworm migration risks continue tonight into tomorrow morning for the lower Ohio River valley and north into the Wabash River valley and portions of the eastern corn-growing region especially in Indiana, Ohio, and Kentucky. South to southwest winds to the east of a rather strong but decaying low pressure system in Nebraska/Iowa will continue to blow north from source regions originating in Arkansas, Louisiana, and Mississippi. Showers and thunderstorms are also expected in this area and could serve as potential insect drop zone regions. Low risks extend north into southern Michigan and east to near the Appalachian Mountains. Later Wednesday into Thursday morning, the risk is reduced to Low risk levels due to predicted weaker winds but areas from far eastern Illinois and southeast Missouri east and northeast into Indiana, Ohio, Kentucky, and Tennessee may still see some isolated corn earworm flights.
Looking ahead to the extended period, the weather pattern across the central and eastern United States is expected to become less active as high pressure builds into the heart of the corn-growing region by late week. With a lack of southerly winds expected, no risk of corn earworm migration is predicted for the extended forecast period.