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: Monday, June 11, 2007, Noon central time
Short-term (present to 48 hours):
Day 1 (Monday 6/11/2007 noon to Tuesday 6/12/2007 noon): Relative Risk of Insect migration into the Midwest: LOW (5-10%): Greatest risk area is west of US 81 and south of I-90, including southern South Dakota, Nebraska, and Kansas.
Click Here For The Day 1 Risk Map (opens a new window)
The surface weather map this morning has an area of low pressure over central Montana with high pressure over Lake Huron with a secondary high pressure over eastern Virginia. Southerly winds are primarily located west of the Mississippi River with southeasterly winds to the east. Precipitation is most common in extreme southwestern Missouri with a few isolated showers in Minnesota.
As the next 24 hours progresses, the low pressure will continue to meander across the northern Rockies or far western Plains as the high pressure continues to rule the roost over the Great Lakes states. Southerly weak flow will continue, especially across the Plains states from source regions in Oklahoma and the Texas panhandle. Some scattered precipitation is expected to develop across the western Plains states, mainly west of US 81 and south of I-90, so a Low risk of insect migration is forecast in this area, with Very low risks north to I-94 and west of the Mississippi River. No risk is forecast east of the Mississippi River due to the influence of high pressure and lack of favorable winds.
Day 2 (Tuesday 6/12/2007 noon to Wednesday 6/13/2007 noon): Relative Risk of Insect migration into the Midwest: LOW (5-10%): Greatest risk is west of I-29 and US 71 south of I-90, including southern South Dakota, Nebraska, and Kansas.
Click Here For The Day 2 Risk Map (opens a new window)
The low pressure currently in Montana is expected to intensify a little bit and also move slightly further east, but the high pressure over the Great Lakes states will continue to influence the weather and wind flow east of the Mississippi River, so little change is expected in the forecast details for Day 2 from Day 1. Due to the possible expected eastward movement of the low pressure, the insect migration risk is shifted just a tad to the east, roughly along the Missouri River and points west, to the south of I-90 where the greatest concentration of showers and thunderstorms exists and where southerly winds are expected to be most common. No risk exists once again to the east of the Mississippi River.
Long-term (Day 3 to Day 5: Wednesday through Saturday):
Days 3-5 (Wednesday 6/13/2007 noon to Saturday 6/16/2007 noon): Relative Risk of Insect migration into the Midwest: Day 3: LOW (5-10%): Greatest risk area is south of I-90 and west of I-29/US 71, including southern South Dakota, Nebraska, and Kansas. Days 4-5: VERY LOW (2-5%): Greatest risk area is south of US 2 and west of the Mississippi River.
Click Here For The Days 3-5 Risk Map (opens a new window)
The low pressure area is expected to remain across the far western Plains and is expected to elongate from extreme southern Canada to western Nebraska. High pressure, however, will continue to remain firm across the Great Lakes or possibly move a little bit to the east, but what you see for the next couple days is what we are expecting through the early part of the weekend, so the insect migration risk area is also expected to change little, with a Low risk across Nebraska and Kansas on Day 3. Much less coverage of precipitation is forecast on Days 4 and 5, and southerly winds are also expected to remain rather weak, so a Very Low risk of insect migration is forecast across the Plains and western Midwest to the west of the Mississippi River through the period.
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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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