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 4, 2007, Noon central time
Short-term (present to 48 hours):
Day 1 (Monday 6/4/2007 noon to Tuesday 6/5/2007 noon): Relative Risk of Insect migration into the Midwest: NONE
Click Here For The Day 1 Risk Map (opens a new window)
The surface weather maps this morning show low pressure over lower Michigan, with a weak cold front or wind shift south of the low roughly along a line from near Detroit to Indianapolis to Louisville and west to Oklahoma City. Scattered showers are rotating counterclockwise around the low pressure, mainly in the Great Lakes states. Across much of the Midwest and Plains, westerly or northwesterly winds are observed, with the only area of southerly winds across southern Ontario and across eastern Ohio and Kentucky.
The low pressure area is expected to continue to move to the northeast, reaching southern Quebec at the end of the forecast period. Precipitation is expected to continue to be rather scattered near the low pressure area, and with no real southerly wind flow or concentrated areas of precipitation across the forecast area, no risk of insect migration is predicted for Day 1.
Day 2 (Tuesday 6/5/2007 noon to Wednesday 6/6/2007 noon): Relative Risk of Insect migration into the Midwest: LOW (5-10%): Greatest risk area is south of I-80 west of US 71, including southern Nebraska, southwestern Iowa, western Missouri, and Kansas. Very low risks extend north to I-94 and east to the Mississippi River.
Click Here For The Day 2 Risk Map (opens a new window)
A new area of low pressure is expected to develop across the Front Range of the Rocky Mountains in eastern Wyoming near Cheyenne. Southerly winds are expected to return with a vengeance to the Plains states, mainly west of I-29/US 71. Precipitation is possible along with the southerly winds, with the best chance between US 36 and I-94 west of I-35, but insects will most likely have a difficult time moving this far north in less than a day, so the chances of significant insect drop out in this area is pretty small. The best chances will be closer to the source regions south of I-80 and west of US 71 in southern Nebraska and Kansas. Further north and east, however, a Very Low risk of insect migration is forecast to account for any insects that may currently exist further north in the Midwest that may move into these areas in association with southerly winds and more widespread precipitation. East of the Mississippi River and north of I-94, no risk of insect migration is forecast due to winds from an unfavorable direction and/or lack of precipitation.
Long-term (Days 3 to Day 5: Wednesday through Saturday):
Days 3-5 (Wednesday 6/6/2007 noon to Saturday 6/9/2007 noon): Relative Risk of Insect migration into the Midwest: Day 3: MODERATE (15-20%): Greatest risk area is north of I-80 between US 81 and Lake Michigan/I-57, including the eastern Dakotas, eastern Nebraska, Minnesota, northern Iowa, Wisconsin, the UP of Michigan, and northern Illinois. Day 4: MODERATE (15-20%): Greatest risk area is north of I-80 and I-74 east of I-35 to I-69, including southeast Minnesota, eastern Iowa, Wisconsin, Michigan, northern Illinois, and northwestern Indiana. Day 5: LOW (5-10%): Greatest risk area is southeast of a line from Flint, Michigan to Milwaukee to Des Moines to Omaha to Goodland, Kansas.
Click Here For The Days 3-5 Risk Map (opens a new window)
The deep area of low pressure forecast to develop over eastern Wyoming is expected to move to near International Falls, Minnesota by the end of the Day 3 forecasting period. A trailing cold front is also expected to move east, reaching along the I-35 corridor through the same period. Showers and thunderstorms are expected to be most widespread north of I-80, with more scattered thunderstorms along the cold front south of I-80. Strong southerly winds from source regions in eastern Oklahoma and Arkansas will blow through the period, bringing the season’s first Moderate risk of insect migration to areas north of I-80 between US 81 and Lake Michigan. Low and very low risks surround the Moderate risk area to the east (I-69/65) and south to the southern boundary of our forecasting region.
By Day 4, the low pressure begins to move into Canada, and is expected to weaken and be located near the Ontario/Quebec border at the end of this forecasting period. The cold front will continue to move to the east, and with strong southerly winds and precipitation continuing along and ahead of the frontal boundary, a Moderate risk of insect migration is forecast between I-35 and I-69 north of I-80 and I-74. Low and very low risks again surround the Moderate risk area all the way east to the Ohio/Pennsylvania border, into Ontario, and south to the southern border east of I-35.
On Day 5, the cold front becomes stationary and flattens out into a west-to-east position, somewhere between I-80 and I-40 as a new area of low pressure develops on the far western end of the front in Colorado. Showers and thunderstorms will be focused near the frontal boundary, and with southerly winds along and south of the front mainly west of I-55 and south of I-80, a Low risk of insect migration is forecast south of a line from Flint to Milwaukee to Des Moines to Omaha to Goodland.
As the week progresses, we will continue to monitor conditions and will provide updates on this first potentially significant insect migration for much of the upper Midwest.
-----------------------------------------------------------------------------------------------------------
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.
-----------------------------------------------------------------------------------------------------------