Corn earworm migration risks continue to remain in the Low category through the next five days as any south to southwest wind flow is expected to remain rather limited. Low migration risks are in place mainly west of I-35 and south of the North Dakota/South Dakota border later this evening and into the overnight hours as a weak pressure gradient between high pressure in the mid-south and a cold front in the northern Plains and upper Midwest produces light southerly winds into this region. The risk spreads southeast with the southward moving cold front by Wednesday night into Thursday morning with areas from Kansas northeast into extreme southeast Minnesota and southern Wisconsin at risk.
By the extended period, southerly flow should eventually retrograde back to the Plains as the initial cold front washes out and new low pressure begins to take shape in the northern Rockies and adjacent areas of Canada. With both the high and low pressure centers of such weak strength, continued feeble southerly winds in between results in only Low migration risks through the period.