Weather Starter: Heat Ratchets Up in the Corn Belt
Temperatures surging into the 90s -- after a few weeks of below-normal temperatures -- are expected in much of the Corn Belt as the week starts, putting a premium on expected rainfall in parts of the region as the soybean crop reaches the homestretch of its most critical development period.
Rainfall prospects look to range from above-normal to normal in the Corn Belt this week as temperatures rise through mid-week, then slide lower toward week's end, forecasters say. These conditions follow a weekend when some parts of the region saw considerable weekend rainfall, according to Harvey Freese of Freese-Notis Weather, Inc.
"Heaviest rainfall was in far southern Iowa, northern Missouri, and western through southern Illinois with 1.00 to 3.00+" amounts in general, but a few spots in south-central Iowa into northeast Missouri received amounts of 3.00 to 5.00+" including 5.83" at Kirksville, Missouri," he says. "Elsewhere in the west, rain amounts were from a few hundredths of an inch to a half inch. Northern parts of Illinois, Indiana, and Ohio were mainly dry with a few showers in Michigan."
Those showers -- some that could develop into more severe storms fueled by seasonally hot temperatures -- are expected to criss-cross the northern Plains and Corn Belt through this week and into next, adds Monday's Commodity Weather Group (CWG) Ag QUICKsheet.
"Additional activity spreads through the northern/eastern Midwest from a series of disturbances through early next week. Scattered showers are also possible in the southwest by tonight/Tuesday and again late in the six- to 10-day and into the 11- to 15-day. While some forecast guidance was hotter/drier in the southwest half of the Midwest due to stronger ridging from Thursday to Monday, our forecast continues to lean toward wetter guidance and limits 90s to mainly the southwest quarter of the belt," according to CWG. "Remaining dry spots in North Dakota, southern Minnesota, eastern/north-central Iowa, southwest Wisconsin, western Michigan, and patchy areas from northern Illinois into southwest Ohio are nearly all likely to see some relief to benefit late soy growth."
Rainfall has generally been fairly scant in all but a few pockets of the Plains and Midwest since July 4, with all but parts of northern Missouri, western Illinois, and parts of Michigan, northwest Iowa and the mid-South region of eastern Oklahoma and Arkansas seeing rainfall totals below normal, with as little as 15% of normal rain falling in parts of north-central Iowa, for example. Any potential damage from that dryness has been kept at bay by lower-than-normal temperatures, though, leading this week's rising temperatures to cause some concern among farmers who haven't seen much rain, but whose crops have made it through the dry spell in good shape . . . up until now.
"I would say that map pretty much says we are no better than last year," says Agriculture.com Marketing Talk veteran adviser Mizzou_Tiger after examining a vegetative index map showing that much of the Corn Belt is on the low side for vegetative greenness heading toward September. "And if you look at the state yields used on the last [USDA Crop Production] report, Iowa is way too high, Illinois is too high, Nebraska is too high, Minnesota is way too high, Indiana is too high, and Ohio is too high."
Moving ahead, it's too early to expect much of any crop damage from ongoing moisture deficits in parts of the Corn Belt, but that's not true everywhere. In general, where the rain falls in the next week is where crop potential stands to remain at the top end of the spectrum through the next week to 10 days, adds Don Keeney, senior ag meteorologist with MDA Weather Services.
"Additional rains in the northwestern and eastern Midwest this week will continue to replenish moisture, which will favor late growth of the soybeans. Additional improvements are expected in northwestern areas in the six- to 10-day period as well. However, the active rains in the northern Plains and southern Prairies will stall spring wheat drydown and early harvesting and will lower quality a bit," Keeney says. "Warm temperatures in the southwestern Midwest later this week are not expected to result in any significant stress on the corn or soybeans. Limited rains in the central and southern Plains this week will allow moisture there to decline again, especially in north-central and southwestern areas."