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: Wednesday, June 27, 2007, 6AM central time
Short-term (present to 48 hours):
Day 1 (Wednesday 6/27/2007 noon to Thursday 6/28/2007 noon): LOW (5-10%): Greatest risk area is along and south of a line from Sault Ste Marie to Green Bay to Omaha to Goodland but north of I-64, including southeast Nebraska, much of Kansas, Missouri, central and eastern Iowa, southern Wisconsin, Illinois, Michigan, Indiana, Ohio, and southwestern lower Ontario.
Click Here For The Day 1 Risk Map (opens a new window)
The surface weather map early this morning has low pressure in Ontario just north of Lake Superior with a cold front southwest of the low through the UP of Michigan, northern Wisconsin, Iowa, and then into extreme southern Nebraska and northern Kansas. Showers and thunderstorms are found in a scattered fashion along the frontal boundary. Southerly or southwesterly winds are observed to the east of the front and northwesterly or northerly winds to the north of the front. High pressure is just off the Carolina coast, with another high pressure building in across south central Canada.
As the next 24 hours progresses, the low pressure is expected to continue to slide to the east, and will likely be over far southeastern Canada or the northeastern United States by the end of this forecasting period. The cold front is expected to advance to the southeast, and will likely be near the I-72/US 36 corridor by midday Thursday. Showers and thunderstorms in at least a scattered fashion are expected to develop right along and in advance of the frontal boundary providing numerous areas for potential insect drop-out. Southerly and southwesterly winds feeding into the insect drop zone areas will likely be rather weak, however, so only a Low risk of insect migration is forecast mainly southeast of a line from Sault Ste Marie to Goodland but north of I-64. To the south of I-64, only isolated or scattered thunderstorms are forecast far in advance of the frontal boundary, so just a Very Low risk of insect migration is forecast across the far southern reaches of our forecast area. Further north, behind and north of the cold front, high pressure from Canada is expected to build in, producing calm or light northerly or northwesterly winds, so No risk of insect migration is forecast north of the front on Day 1.
Day 2 (Thursday 6/28/2007 noon to Friday 6/29/2007 noon): Relative Risk of Insect migration into the Midwest: VERY LOW (2-5%): Greatest risk area is along and south of US 24 west of I-69, and along and south of I-69 to the east, including much of Kansas, Missouri, central and southern Illinois, Indiana, Kentucky, Ohio, far southeast Michigan, and far southern Ontario near Windsor and Hamilton.
Click Here For The Day 2 Risk Map (opens a new window)
The low pressure area is expected to move off into the Atlantic Ocean during the Day 2 forecasting period, while the cold front continues to move to the southeast. The front is expected to slow in forward motion as it becomes more west to east versus its current alignment which is more north and south. Showers and thunderstorms are expected to continue and will likely redevelop throughout the Day 2 forecasting period along and south of the front. Weak southerly winds, however, even weaker than what is expected the next 24 hours, precludes any risk higher than a Very Low risk for the southeastern half of the forecast area southeast of a line from Toronto to Chicago to Goodland, Kansas. No risk of insect migration is forecast north of the front as high pressure is likely to continue to build in across the northern Plains and upper Midwest.
Long-term (Day 3 to Day 5: Friday through Monday):
Days 3-5 (Friday 6/29/2007 noon to Monday 7/2/2007 noon): Relative Risk of Insect migration into the Midwest: Day 3: VERY LOW (2-5%): Greatest risk areas are 1) along and south of I-44 and I-70, including southern Missouri, southern Illinois, southern Indiana, Kentucky, and southern Ohio; and 2) along and west of US 81 in the Plains, including the western Dakotas, western Nebraska, and western Kansas. Day 4: VERY LOW (2-5%): Greatest risk area is along and west of I-29/US 71, including the Dakotas, Nebraska, and Kansas. Day 5: LOW (5-10%): Greatest risk area is along and west of I-35 and also west of US 53 in Wisconsin, including the Dakotas, Nebraska, Kansas, western Iowa, Minnesota, and far northwestern Wisconsin.
Click Here For The Days 3-5 Risk Map (opens a new window)
During the Day 3 forecasting period, the cold front will likely continue sliding to the southeast, and will take its precipitation and associated insect drop out risk with it. The front is expected to be mainly along and south of I-70 to the east of the Mississippi River and along and south of I-44 to the west of the Mississippi River at the start of the Day 3 period. Southerly winds will continue ahead of the front but will be rather weak, so just a Very Low risk of insect migration is forecast. A secondary area of insect migration risk is forecast on Day 3 to the west of US 81 in response to a new low pressure system that is expected to develop in eastern Wyoming or Montana. As this low develops, southerly winds will increase across the Plains and provide a regional insect migration risk from source regions from the Texas and Oklahoma panhandles into Kansas and possibly southern Nebraska. Just a Very Low risk of insect migration is forecast at this time due to the southerly winds just commencing during this period. No risk of insect migration is forecast over the upper Midwest and Great Lakes states as high pressure will dominate the weather.
On Days 4 and 5, the cold front is expected to move far enough south to pose no risk of insect migration across the southern Midwest, so the focus for these two days will be with the developing low over the upper Rockies or western Plains states. The low pressure will likely hold firm in the eastern Wyoming, Montana, or far western Dakotas through the forecasting period, so southerly winds will be rather persistent to its east. Precipitation that may provide insect drop zones is expected to be rather isolated and mainly focused near the Canadian border, so just a Very Low risk of insect migration is forecast on Day 4 west of I-29 and US 71, with the risk area spreading east to I-35 and US 53 in Wisconsin by Day 5 as southerly or southwesterly winds lock in further east with time. This system will need to be monitored given its favorable position for insect migration across the Plains states and the possibility of more widespread precipitation going into next week. We will provide early morning updates the rest of this week and adjust forecast risk levels and locations as needed.
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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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