Insect Migration Risk Forecast (IMRF)
2007 Growing Season
ACCEC (Analytical Center for Climate and Environmental Change)
Mike Sandstrom and Dave Changnon
Department of Geography
Northern Illinois University
DeKalb, IL 60115
wxtrw44@yahoo.com and dchangnon@niu.edu
Daily Forecast (updated Monday-Friday by Noon Central Time except holidays)
Forecast Release: Tuesday, May 15, 2007, 11AM Central Time
Welcome to the 2007 IMRF Forecasting Season!
Short-term (present to 48 hours):
Day 1 (Tuesday 5/15/2007 noon to Wednesday 5/16/2007 noon): Relative Risk of Insect migration into the Midwest: VERY LOW (2-5%): Greatest risk area is along and south of US 54 in Missouri, along and south of US 24 in Illinois, and south of I-94 to the east including far southern Michigan, extreme southwestern Ontario, Indiana, Ohio, and Kentucky. No risk exists to the northwest of this area.
Click Here For The Day 1 Risk Map (opens a new window)
The surface weather maps this morning show a rather vigorous area of low pressure over Lake Huron with a cold front draped to the west and south of the low through northern lower Michigan into southern Wisconsin, eastern Iowa, northwest Missouri, and southeastern Kansas. Showers and thunderstorms are lined up along the entire length of the front. High pressure is located off the North Carolina coast so southerly winds are found across the entire Midwest into far southwestern Ontario. Behind the front, northwesterly winds are found with a rather large area of high pressure building into eastern Montana.
As the next 24 hours progresses, the Lake Huron low pressure will continue to move off to the east, dragging the cold front and attendant precipitation with it. Expect southerly winds to continue ahead of the front, feeding from low-level source regions along I-40 from Oklahoma City east to Nashville. Due to the rather short duration of southerly winds and the distance that migratory insects would have to travel from these source regions (where CEW trap counts are increasing in numbers), only a Very Low risk of insect migration is forecast along and ahead of the frontal boundary over the next 24 hours over roughly the southeastern 2/5 of our forecasting area. No risk of insect migration exists in the northern Plains states and upper Midwest as northerly winds will continue through at least the next 24 hours.
Day 2 (Wednesday 5/16/2007 noon to Thursday 5/17/2007 noon): Relative Risk of Insect migration into the Midwest: NONE
Click Here For The Day 2 Risk Map (opens a new window)
The cold front is expected to push through the entire Midwest and Ontario province by the start of the Day 2 forecasting period as high pressure builds into the Plains states. To the west of the cold front, northerly or northwesterly winds are expected to cover virtually the entire forecasting region, so no risk of insect migration is forecast for the Day 2 period.
Long-term (Days 3 to Day 5: Thursday through Saturday):
Days 3-5 (Thursday 5/17/2007 noon to Saturday 5/19/2007 noon): Relative Risk of Insect migration into the Midwest: Day 3: NONE, Days 4-5: VERY LOW (2-5%): Greatest risk area is along and west of I-35 in the Plains states, western Iowa, and western Minnesota.
Click Here For The Days 3-5 Risk Map (opens a new window)
High pressure is expected to remain in control of most of the Midwest and Ontario through the period, but by Days 4 and 5 it will begin to drift off the southeast bringing return southerly flow into the Plains states as low pressure develops over Montana and the Dakotas. By Saturday, the high pressure is expected to be in the Ohio River valley, bringing southerly winds as far east as the Mississippi River. The strongest winds, however, will be west of I-35 and will be feeding from source regions primarily in the Texas and Oklahoma panhandles and points west between I-25 and I-35. A very low risk of insect migration is forecast for both Days 4 and 5 to account for the risk of migratory insects moving from this region northward into the central and northern Plains on Friday and Saturday.
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Mike Sandstrom and Dave Changnon
Department of Geography
Northern Illinois University
DeKalb, IL 60115
E-mail: wxtrw44@yahoo.com and dchangnon@niu.edu
Temporary IMRF website: http://www.maplecity.com/~sand/cew/imrf.html
DISCLAIMER: The content in this document, and any associated figures, is strictly the opinion of the authors, and should be used for informational purposes only. The authors
assume no liability to those who may use the above content for IPM or other processes.
NOTE: This forecast, while initially developed specifically for migration of corn earworm (CEW), is applicable for all other migratory insects in the Midwest as well, such as the potato leafhopper and armyworm.
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