Moderate corn earworm migration risks are predicted late this evening into early Friday morning from Nebraska, Iowa, Illinois northward into Minnesota, Wisconsin, southwest lower Michigan, and northwest Indiana. Rather strong south to southwest winds originating in Kansas are expected to blow north and northeast into the corn-growing region and upper Midwest to the east of a southeastward-moving cold front. Precipitation is possible along and east of this front which may enhance insect drop-out in some areas. Low risks extend east into the Great Lakes region as well.
As the cold front presses to the southeast, it is expected to weaken somewhat as its parent low pressure moves well north into Canada. Southwest wind flow to the south of the front will also weaken as a result, so only Low risks are predicted Friday night into Saturday morning from Iowa and Missouri into Illinois, southern Wisconsin, Indiana, Ohio, Michigan, and southwest Ontario.
No migration risk is predicted for the remainder of the period as northeasterly winds build into much of the corn-growing region and upper Midwest. Additionally, the pattern should remain in place for several days as a tropical system along the Gulf coast meanders in place and keeps persistent northeast winds blowing to its north.