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, June 12, 2007, Noon central time
Short-term (present to 48 hours):
Day 1 (Tuesday 6/12/2007 noon to Wednesday 6/13/2007 noon): Relative Risk of Insect migration into the Midwest: LOW (5-10%): Greatest risk area is south of I-94 west of I-29/US 71, including southern North Dakota, South Dakota, Nebraska, and Kansas.
Click Here For The Day 1 Risk Map (opens a new window)
The surface weather maps this morning have a low pressure area over North Dakota, with a weak cold front to the southwest of the low into eastern Wyoming. Little to no precipitation is observed in association with this surface system at this time. High pressure is located near Sault Ste Marie, Michigan, and is producing fair weather across the Great Lakes states and Midwest in addition to producing winds from an easterly component on its south side. Southerly winds are very common across the Plains, mainly west of I-29. Showers and thunderstorms are once again occurring in southeastern Kansas and southwestern Missouri where people wish they would stop.
As the next 24 hours progresses, the low pressure is expected to move to the north into the Canadian prairies, with the cold front sagging to the southeast into the High Plains. Showers and thunderstorms are expected to develop in earnest along the cold front, and with southerly winds expected to continue through the period especially along and west of I-29 and US 71, a Low risk of insect migration is forecast in this area. Very low risks are placed further east to the Mississippi River where much more scattered precipitation may occur and also where winds will be from a more direct southerly component. No risk of insect migration is forecast further east due to high pressure and unfavorable wind direction and flow.
Day 2 (Wednesday 6/13/2007 noon to Thursday 6/14/2007 noon): Relative Risk of Insect migration into the Midwest: LOW (5-10%): Greatest risk area is along and south of I-94, and west of I-35 north of I-80, and west of US 71 south of I-80, including southern North Dakota, southwestern Minnesota, South Dakota, northwestern Iowa, Nebraska, and Kansas.
Click Here For The Day 2 Risk Map (opens a new window)
Low pressure is expected to continue to move to the east or northeast, with the cold front also advancing to the east. Showers and thunderstorms are expected to continue along and ahead of the front with some of the activity making it into Minnesota during this forecasting period. High pressure, however, will continue to act as a blocking mechanism, keeping the front from moving further to the east. With southerly flow continuing along and ahead of the front, we will continue to forecast a Low risk of insect migration but overall the southerly flow is rather weak so higher risks are not justified at this time. Very low risks of insect migration exist further north and east, mainly west of I-39 or US 51 in Wisconsin to the north of I-94, and west of the Mississippi River south of I-94. No risk of insect migration is forecast to the east as wind flow continues from an unfavorable direction.
Long-term (Day 3 to Day 5: Thursday through Sunday):
Days 3-5 (Thursday 6/14/2007 noon to Sunday 6/17/2007 noon): Relative Risk of Insect migration into the Midwest: Days 3-4: VERY LOW (2-5%): Greatest risk on Day 3-4 is west of I-29/US 71, including North Dakota, South Dakota, Nebraska, and Kansas. Day 5: LOW (10-15%): Greatest risk area is west of I-35, including North Dakota, Minnesota, South Dakota, Nebraska, Kansas, western Iowa, and northwestern Missouri.
Click Here For The Days 3-5 Risk Map (opens a new window)
The low pressure area in Canada and its attendant cold front is expected to largely wash out or dissipate, so the threat of insect migration and drop out really begins to decrease starting on Day 3 into Day 4 related to this system. Throughout the period, high pressure will continue to slowly move to the east, and by Day 5 is expected to be near the mid-Atlantic coast. As the high moves to the east and a new area of low pressure organizes across the Plains, southerly winds will return to much of the Midwest and Plains states and increase in speed through time. Precipitation is expected to redevelop across the western Plains states potentially by Day 4 and then become more widespread by Day 5 and beyond. At this time, a very low risk of insect migration is forecast on Days 3-4 across the extreme northern Plains, with a Low risk on Day 5 west of I-35. The system late this weekend and early next week bears watching due to the potential strength and expected widespread precipitation, so continue to monitor our forecasts this week for updates.
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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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