Two systems have already moved through the Western Corn Belt. One occurred Aug. 19 into Aug. 20, the other Aug. 21 into Aug. 22. Now a third system is traversing the area Aug. 24. All three have had and are having overall positive impacts for the Western Corn Belt's drought. There have been some holes over the west in southeast South Dakota, northeast Nebraska, and southern Iowa. But good rainfall over an inch has helped the final fill stages of corn and soybeans stave off any more losses elsewhere.
Crop conditions fell again this week, despite the good rainfall late last week. In North Dakota, where there was widespread rainfall over 1 inch and large pockets of 2-to-4 inches, good-to-excellent corn conditions fell another four points to 16% and soybeans fell another two points to 12%.
This goes to show that we are about a month too late. Had an active northern weather pattern shown up in mid-to-late July instead of in August, the outlook for the Corn Belt's corn and soybeans could have been much different. But when you're a farmer sitting in drought with the prospect of La Nina's return to produce a potentially drier winter and early spring in the Western Corn Belt, you probably take the rain even if it is late.
And the active pattern which has brought good rainfall since Aug. 19 will continue through the end of the month. As opposed to most of the summer, when a ridge was very stubborn in western North America, troughs and small disturbances have been able to move rather steadily into the Pacific Northwest, then across the U.S.-Canada border. Several disturbances across the North Pacific are lining up to take their turn.
The ridge has now shifted to the east. As systems try to move into it, they will be mostly stalled or forced northward. This will lead to decreasing rainfall chances and amounts across the Eastern Corn Belt, in a reversal of what we had seen throughout June, July, and into early August. But for the Western Corn Belt, it will be near-daily chances of rain through at least Aug. 29 with another system taking shape as the calendar switches over to September.
That eastern ridge has a connection to the Southern U.S. as well. Temperatures in the 90s Fahrenheit, with a few postings over 100 degrees in the Plains, are occurring south of the main rainfall zone farther north. Mostly south of Interstate-80, temperatures and humidity have increased and will cause stress to the remaining filling summer crops. But this late in the season, it will be hard to undo the overall good conditions that we have seen thus far in the growing season. Based on satellite observations, crop health from eastern Kansas through Missouri and the Eastern Corn Belt states is looking terrific. Recent rainfall across much of this area should sustain the final push for fill despite the heat stress.
That may be different for parts of the Delta region, however. Rainfall has not been as consistent in this area over the last month as it has north of the Ohio and Missouri Rivers. Dryness has started to creep into the region on the Drought Monitor. While good-to-excellent crop conditions for both soybeans and cotton on the latest USDA report are all fairly high, even with respect to normal, there is still a good portion of the season yet to go before harvest. The stress may be enough to take the top off of yields right at the finish line, especially in Arkansas.
John Baranick can be reached at firstname.lastname@example.org
(c) Copyright 2021 DTN, LLC. All rights reserved.