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 29, 2007, 6AM central time
Short-term (present to 48 hours):
Day 1 (Friday 6/29/2007 noon to Saturday 6/30/2007 noon): Relative Risk of Insect migration into the Midwest: VERY LOW (2-5%): Greatest risk area is west of I-29, including the Dakotas, Nebraska, and Kansas.
Click Here For The Day 1 Risk Map (opens a new window)
The surface weather map early this morning has a cold front roughly along the Ohio River valley with scattered precipitation especially along and just north of the front in Kansas, Missouri and points south, with additional much more scattered areas of rain in Indiana and Ohio. High pressure is currently located near Minneapolis. Winds across the forecast region are mostly calm or across the Plains are out of the southeast but still weak overall.
During the next 24 hours, the cold front will continue to slide to the southeast and is forecast to be south of our forecasting region by midday Saturday. This front, however, poses little to no insect migration risk due to weak or non-existent wind flow in the vicinity of the front and points south, and with precipitation continuing in insect source regions across Oklahoma, eastern Kansas, Missouri, and Arkansas, there is no risk of insect migration forecasted in association with this front. Further west, however, low pressure is currently organizing in eastern Montana and this is expected to cause decent southerly flow to initiate across the Plains, especially west of I-29. Little to no precipitation is expected, however, so only a Very Low risk of insect migration is forecast. No risk of insect migration is expected across the Great Lakes states as this area will be under the influence of high pressure.
Day 2 (Saturday 6/30/2007 noon to Sunday 7/1/2007 noon): Relative Risk of Insect migration into the Midwest: VERY LOW (2-5%): Greatest risk area is west of I-35, including the Dakotas, Nebraska, Kansas, western Iowa, far northwestern Missouri, and much of Minnesota.
Click Here For The Day 2 Risk Map (opens a new window)
The low pressure in Montana will become the main focus of the forecast for the next several days as it is expected to continue to develop across the Plains. High pressure is expected to continue sitting over the Great Lakes region. Southerly winds will be especially prevalent across the Plains, but will likely expand further to the east into Minnesota and Iowa. Again, however, showers and thunderstorms to the south in active insect source regions will limit the potential for movement northward. Also, only isolated or scattered precipitation is expected with low further north, so given these factors, only a Very Low risk of insect migration is forecast mainly west of I-35. No other areas of insect migration risk are forecast due to high pressure remaining in control across the Great Lakes states.
Long-term (Day 3 to Day 5: Sunday through Wednesday):
Days 3-5 (Sunday 7/1/2007 noon to Wednesday 7/4/2007 noon): Relative Risk of Insect migration into the Midwest: LOW (5-10%): On Day 3, the greatest risk area is southeast of a line from Sheridan, Wyoming to Bismarck but west of Lake Michigan and I-55, mainly north of I-44, including southeast North Dakota, South Dakota, Nebraska, Kansas, Minnesota, Iowa, northern and central Missouri, Wisconsin, and western Illinois. By Day 4, the greatest risk area is mainly east of a line from Rapid City to Fargo and south of I-94 west of the Mississippi River but south of Lake Superior to the east of the Mississippi River, and west of I-55, including South Dakota, Nebraska, Kansas, southern Minnesota, Iowa, Missouri, Wisconsin, and western Illinois. On Day 5, the greatest risk area is southeast of a line from North Platte to Sioux City to Duluth, but west of I-69 and I-65, including southeastern Minnesota, Iowa, central and eastern Nebraska, Kansas, Missouri, Illinois, Wisconsin, western Michigan, western Indiana, and far western Kentucky.
Click Here For The Days 3-5 Risk Map (opens a new window)
Throughout the Day 3-5 period, the low pressure in the Plains will strengthen and begin to the slide to the east as high pressure finally gives way and moves to the southeastern United States. A warm front will serve as the focal point for mainly late day and nighttime clusters of showers and thunderstorm immediately along and just north of the frontal boundary. Southerly winds will continue to the south of the warm front and also east of a developing cold front across the Plains. The insect migration risk will shift east through the period, with the main focus on Day 3 over the Plains states west of I-35, then over the Missouri River valley on Day 4, and then by Day 5 is approaching the Mississippi River valley. Only a low end Low risk of insect migration is forecast, however, due to rainfall potentially continuing over the southern Plains that may mitigate insect activity in the source region and also not the most favorable wind speed for movement. We will continue to monitor this system over the weekend and have an update next Monday, July 2.
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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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