Forecast: Slight Relief in Temperatures, but with Little Rain - UNL CropWatch, July 9, 2012
July 9, 2012
An upper air trough over the central U.S. is providing some relief this week from the wave of 90-100°F temperatures. As this trough moves into the upper Great Lakes, weather models indicate that it will deepen over the eastern Corn Belt for much of next week.
As this trough strengthens, the central Plains upper air ridge is projected to retrograde to a position over the north central Rockies and toward the end of the week, we’ll see a gradual warming trend back into the low to mid 90s.
Anytime we see a northwest flow aloft, there is always the possibility that pieces of energy will move southeastward and generate thunderstorm activity. It is virtually impossible to pinpoint where the activity will develop, but at least rainfall chances will be considerably higher than they were when the atmosphere was capped under the recent dome of high pressure.
The Nebraska Agricultural Statistics Service indicated that 25% of the corn crop had reached the silk stage as of July 2, an increase from 4% a week earlier. I would anticipate that at least 55% of the crop will be in the silk stage or beyond when the new estimates are released on July 10. Although cooler temperatures may help alleviate pollination stress, rainfall will determine the extent of kernel abortion during the critical grain fill period.
If moisture fails to materialize before temperatures return to the 90s next week, producers may have to wait until July 20 before another trough is projected to flatten the upper air ridge that builds back into the central Plains during the latter half of next week. Pollination stress is likely occurring on dryland corn and will only intensify if moisture is a bust over the next few days.