Martell: Strong Corn Planting Progress Last Week, Sharp Cooling to Stall Development

By: Gail Martell

May  12,  2014

Gail Martell has been working as an agricultural meteorologist for 30 years. She began analyzing the relationship between weather and crop production with EF Hutton's New York Commodity Department in the late 1970s as the first Wall Street meteorologist. She has been a featured speaker with the National Association of Wheat Growers, the Alberta Grain Growers, the Illinois Farm Bureau and Pro Farmer seminars.. Martell served on the Midwest Governor's Commission on Drought in 1988 and was an invited El Nino specialist at the 2002 Agricultural Outlook Forum sponsored by USDA. Martell has a Master's Degree in Meteorology from the University of Wisconsin, Madison writing her thesis on The Midwest Drought of 1983 and Its Impact on U.S. Corn Production. Click here for more information on her weather services.

Corn Planting Progressing, Sharp Cooling to Stall Development

The Midwest received scattered strong showers last week, but less than expected, allowing corn planting to make good progress. Strong warming has finally developed in the Upper Midwest, where conditions much of the spring has been cold. Warmth and strong sunshine has strongly improved conditions in the northern corn belt. Soil temperatures have finally crossed the 50 F threshold for seed germination in Minnesota, Wisconsin, northern Iowa and Michigan.


Perhaps 50% of US corn has been planted, up from 29% May 4. The USDA will release updated planting statistics this afternoon.

Fine sunny warm weather will give way to sharply cooler conditions this week. Midwest temperatures are predicted to plummet 6-12 degrees F below normal, when a cool Canadian air mass sinks into the central United States.

A freeze is possible tonight on the High Plains in northwest Kansas, Colorado and western Nebraska. Wheat was just beginning the flowering - heading stage on May 4 with 2% headed on the northern High Plains. A hard freeze causes severe, irreversible damage in wheat, as freezing temperatures kills the pollen that fertilizes the grain heads. A hard freeze, if it develops, would be another setback for hard red winter wheat. Historic drought has unfolded in the 3-top bread wheat states Kansas, Oklahoma and Texas winter into spring.

Hard-Freeze-Predicted-on-High-Plains.jpgNorth Dakota is the second biggest US wheat state, behind Kansas, growing hard red spring wheat. Planting has been delayed by persistent cold. Just 5% of spring wheat was seeded May 4, some 2 weeks behind schedule. Heavy rain recently has kept farms sidelined. Not much progress in wheat planting is anticipated in the new report for May 11.

Midwest Forecast Rainy, Then Colder

Significant rainfall is coming to the Midwest as a slow-moving cool front presses east through the US heartland. Midwest rainfall chances for rainfall are 85-90% today and tomorrow with a slow-moving cold front. Heavy rainfall, .75 - 2 inches, is predicted in the eastern two-thirds of the Midwest and Mid South.

Strong-Midwest-Showers-This-Morning.jpgThe morning radar reveals snow showers in Colorado and western-Nebraska and areas of strong thunderstorms in Iowa, Wisconsin and Ohio.

This is the beginning of a stormy, wet period in the Midwest. The atmosphere is loaded with water vapor, as southerly winds from the Gulf of Mexico have produced high Midwest humidity and an unstable atmosphere for showers. A strong, slow-moving cold front would be the trigger for recurring thunderstorms.

Unseasonable cold temperatures are predicted after the front moves through. A cold Canadian air mass has begun its descent into the Great Plains and would gradually overtake the Central United States this week. For the Midwest, upper 50s-low 60s F would be the daily maximum temperatures and upper 30s-low 40s F at night. As example, Mason City, Iowa on Tuesday is expecting 58 F for a high temperature and a night low of 39 F, following summer-like warmth today. The unseasonable cold would dominate the central third of the United States this week.

Corn development would stall due to the cold, as the Upper Midwest daily mean temperatures drop below 50 F, the threshold for corn germination.