The central United States weather pattern is expected to undergo some changes from one dominated by west or northwest flow to increasingly south to southwest flow. The result will be an increase in southerly winds from corn earworm source regions in the southern Plains later this week and into next weekened. At this stage of the growing season, however, only Low corn earworm migration risks are predicted despite a favorable weather pattern for more widespread south to north migration. Risks start Wednesday night into Thursday morning as low pressure becomes more organized in the northern Rockies and high pressure currently in the southern Midwest begins moving east into the Ohio River valley. Southerly winds are expected to return to the Plains initially and then spread east by this weekend. Low corn earworm migration risks encompass much of the corn-growing region by the weekend as a cold front begins to push east into the Midwest, southerly winds expand further east, and precipitation serves as potential drop zone regions.