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: Friday, June 8, 2007, Noon central time
Short-term (present to 48 hours):
Day 1 (Friday 6/8/2007 noon to Saturday 6/9/2007 noon): Relative Risk of Insect migration into the Midwest: LOW (5-10%): Greatest risk area is east of I-65 and I-69 south of I-80 and I-90, including far eastern Indiana, Ohio, and Kentucky.
Click Here For The Day 1 Risk Map (opens a new window)
The surface weather map this morning had low pressure over northeastern Ontario with a cold front along the eastern shore of Lake Michigan and the I-57 corridor south to I-40 west of Memphis. Showers and thunderstorms are common along the southern end of the front, mainly south of I-74, with little to no activity further north. High pressure is currently located over Colorado, with northwesterly winds to the east of the high but west of the cold front across areas west of the Mississippi River. Southerly or southwesterly winds continue to the east of the cold front but are weaker than the past few days.
The cold front will continue to make good southeastward progress the next 24 hours, and is expected to exit the southeastern forecast area by early Saturday morning. Showers and thunderstorms will continue especially south of I-70 with more scattered activity further north, so the best insect migration risk is placed south of I-80 and I-90 to the east of I-65 and I-69, with very low risks further north to I-69 in Michigan and far southwestern Ontario near Windsor. No risk of insect migration is forecast across the rest of the Midwest and Plains as this area will remain under the influence of high pressure and northwesterly winds.
Day 2 (Saturday 6/9/2007 noon to Sunday 6/10/2007 noon): Relative Risk of Insect migration into the Midwest: LOW (5-10%): Greatest risk area is west of US 71 and I-29 south of I-80, including southern Nebraska, Kansas, and far western Missouri.
Click Here For The Day 2 Risk Map (opens a new window)
High pressure moves from Colorado to Indiana or Illinois by midday Sunday. Southerly winds will return to the Plains ahead of a developing low pressure in eastern Colorado. The frontal system that passed through the Plains on Thursday is expected to move back to the north as a warm front, and may serve as the focal point for scattered to possibly heavier coverage showers and thunderstorms Saturday afternoon into Saturday night. Given the strength of southerly winds and expected precipitation, a Low risk of insect migration is forecast mainly across Kansas and extreme southern Nebraska. Elsewhere, no risk of insect migration is forecast due to the influence of high pressure or the lack of favorable winds.
Long-term (Days 3 to Day 5: Sunday through Wednesday):
Days 3-5 (Sunday 6/10/2007 noon to Wednesday 6/13/2007 noon): Relative Risk of Insect migration into the Midwest: LOW (5-15%): Greatest risk is along and west of the Mississippi River and south of I-90, including far southern South Dakota, Nebraska, Kansas, Iowa, and Missouri.
Click Here For The Days 3-5 Risk Map (opens a new window)
The low pressure area will continue to meander across the far western Plains states with southerly winds continuing ahead of the low but mainly west of the Mississippi River as high pressure is expected to remain anchored over the far eastern Midwest or New England states throughout much of next week. A rather diffuse boundary to the east of the low pressure is expected to waffle around the Plains states, and its position and strength will be dependent on the occurrence of organized thunderstorm clusters. Pinpointing where these thunderstorm clusters will originate and track several days out is not met with much confidence, so we will forecast a rather broad but fairly low risk of insect migration at this time where southerly winds will be present and the chance of precipitation exists. We will continue to watch daily occurrences of precipitation across the Plains this weekend and into early next week, and have updates in the forecast on Monday and throughout next week.
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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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