Weather forecasts don't hold much promise for above or even normal precipitation through October, according to Al Dutcher, state climatologist at the University of Nebraska-Lincoln.
Dutcher says that the U.S. Drought Monitor, based at UNL, points to abnormal dryness expanding eastward.
"Current patterns tend to be replicating some of the patterns the state saw last July and August," he says. "Temperatures are forecast to be above normal for the southwest two-thirds of the state and equal chances for the remainder of the state. This may be good news for northeast Nebraska which needs to make up some crop maturation due to planting delays.
Due to the cool, wet spring, crops are about 10-14 days behind normal across the state. The majority of the corn crop is into its pollination stage, making precipitation critical at this time and through the grain fill process, according to Dutcher.
Dutcher says that recent stream flows also have dropped significantly even with some of the short-term moisture gains the state saw this spring. "Although we've had short-term moisture gains, it did not fill that deep soil moisture profile below the rooting zone of a crop that moves toward the aquifer," he adds. "This is a residual impact of last year's drought, which had a significant impact on aquifer levels. We didn't get the recovery we needed last year."
Irrigation is running around the clock across the state, but there is some concern in areas with lower flow rates, particularly in sandy soils. In addition, areas with limited water deliveries make it difficult to apply enough water to carry average yields.
Winds are always a concern." The last four to five weeks, water use by crops in the pollination stage is at .28 to .38 of an inch of water per day, so about an inch of water every three days. That equates to about two inches of rain per week for the next month, so even with normal precipitation soil moisture profiles will continue to decrease going forward, Dutcher says.
He says it's not out of the question to make up ground mid- to late-August if temperatures stay slightly above normal. "Temperatures begin to drop off in mid-August, so if they are slightly above average, that would help crops make up ground," he says. "So far, the majority of the state is not at substantial risk for freeze damage. There may be a higher risk in extreme northeastern Nebraska in areas where corn had to be replanted. So we'll take a usually warm September and temperatures in August that mirror those in July," he says.