Corn earworm migration risks are on the increase over the next five days as an active weather pattern remains in place across much of the corn-growing region. Initially, Low migration risks are predicted for the eastern Great Lakes region, southwest Ontario, and the far eastern Midwest later this evening and into early tomorrow morning as a cold front currently across the central corn-growing region moves east. Enough southerly winds should be present in this area to result in the possibility for mainly isolated corn earworm flights from any source regions currently present in Tennessee.
The main corn earworm migration focus in the next five days will be from Day 2 through Day 5 as another low pressure system develops and moves into the far western Plains states. As has been the case the past few weeks, a warm front is expected to set up shop between I-70 and I-80 before lifting north at the end of the forecasting period and should result in periodic shower and thunderstorm chances especially along and north of the boundary. These precipitation areas could serve as insect drop zones as southerly winds and increasing heat/humidity to the south of the boundary feed into the corn-growing region for several days. Low risks are initially in place across the Plains and southwest corn-growing region on Day 2 (Thursday into Friday) with Moderate risks predicted on Days 3 and 5 (this weekend and early next week) mainly across southeast Nebraska, southern Iowa, western Illinois, Missouri, and Kansas as southerly winds over multiple days serve as the corridor for corn earworm migration to the north.