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, May 16, 2007, 11:30AM Central Time
Short-term (present to 48 hours):
Day 1 (Wednesday 5/16/2007 noon to Thursday 5/17/2007 noon): Relative Risk of Insect migration into the Midwest: NONE
Click Here For The Day 1 Risk Map (opens a new window)
The surface map this morning shows low pressure over southern Ontario with a cold front arcing southwest from the low along the western edge of the Appalachian Mountains. Showers and storms were rather common up and down the length of the front, but are now largely to the east of the Midwest. Behind the front, northerly or northwesterly winds are found across the entire Midwest and western Ontario, with high pressure slowly building into the Plains states from the Dakotas south to Oklahoma and Texas.
Winds of a northerly component will continue across the entire forecasting area today into tomorrow morning, so no risk of insect migration is forecast for Day 1 due to unfavorable wind direction for insect migration this time of year.
Day 2 (Thursday 5/17/2007 noon to Friday 5/18/2007 noon): Relative Risk of Insect migration into the Midwest: VERY LOW (2-5%): Greatest risk area is across far southwest Kansas, south of I-70 and west of I-135/I-35.
Click Here For The Day 2 Risk Map (opens a new window)
High pressure is expected to begin moving slowly to the east during the Day 2 period, reaching into northern or central Illinois by Friday morning. To the east of the high, northerly winds will continue so no risk of insect migration is forecast in these areas. To the west of the high, however, southerly winds will begin to commence once again ahead of a developing area of low pressure over far eastern Montana. Southerly winds are expected to originate in the Texas/Oklahoma panhandles and at least a small chance of precipitation exists during Friday morning in association with the southerly winds in far southwestern Kansas. Due to the short distance that any insects originating in potential insect source regions would have to travel and at least the possibility of precipitation, a Very Low risk of insect migration is forecast across far southwest Kansas for very late in the Day 2 period.
Long-term (Days 3 to Day 5: Friday through Sunday):
Days 3-5 (Friday 5/18/2007 noon to Sunday 5/20/2007 noon): Relative Risk of Insect migration into the Midwest: Day 3: VERY LOW (2-5%): Greatest risk area is south of I-80 and west of I-35 in Kansas, southern Nebraska, and southwest Iowa. Day 4: VERY LOW (2-5%): Greatest risk area is south of I-80 and west of US 65, including Kansas, southern Nebraska, southwest Iowa, and western Missouri. Day 5: LOW (5%): Greatest risk area is over Kansas and southwest Missouri, but as far north and east as I-80 and west of US 63 in southern Nebraska, southern Iowa, and central Missouri.
Click Here For The Days 3-5 Risk Map (opens a new window)
The area of high pressure forecast to be over Illinois on Friday is expected to drop to the southeast, reaching eastern Arkansas or western Tennessee by the end of this forecasting period. To the west of the high pressure, southerly or southwesterly winds are expected to continue through the period and expand eastward with time, feeding from source regions in western Texas, eastern New Mexico, and the Texas/Oklahoma panhandles. Despite the southerly winds, little to no precipitation is currently expected across the Plains and lower Missouri River valley through the period. However, with persistent southerly winds for potentially several days, a Very Low risk of insect migration is forecast across the southwestern portion of the forecast area on Days 3-4 due to close proximity to insect source regions. A Low risk of insect migration is forecast on Day 5 across Kansas and southwestern Missouri due to 2-3 days of persistent southerly winds and being closest to potential insect source regions. If precipitation enters the picture in the next couple days, we may increase the migration risk but the expected lack of precipitation precludes forecasting a higher risk at this time.
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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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