With a quick moving northwest flow weather pattern becoming established across much of the central and eastern United States, corn earworm migration probabilities will remain low, if any, over the next five days.
Low risks are predicted south of the South Dakota/Nebraska border into Kansas and also northeast into portions of Missouri as primarily weak south to southwest winds blow north into these areas east of developing low pressure across the northern Rockies. High pressure over the Great Lakes region continues to limit any further eastward expansion. The Rockies low moves east into the upper Midwest later Saturday and into Sunday as a cold front pushes across the Plains. Mainly weak south to southwest winds in advance of the front will be common right through the heart of the corn-growing region from eastern Kansas and Missouri north into Iowa, Illinois, southern Minnesota, and Wisconsin. Despite a somewhat favorable weather setup for migration, only weak southerly winds are expected so just a Low risk is in place for this time period. Thereafter, northwesterly winds and cooling temperatures result in a no risk extended forecast into the middle of next week.