Late-Summer Drought Outlook for Midwest

Corn Belt Drought Outlook for Reproductive Corn and Soybeans

John Baranick
By  John Baranick , DTN Meteorologist
The rainfall pattern we have seen in June is likely to continue through August. (DTN graphic)

A dry northwest and a wet southeast Corn Belt has been the pattern during the past month or so. Some showers have moved through at times across the Dakotas, western Minnesota, Nebraska and northwest Iowa, but amounts over 1 inch have been mostly in smaller, isolated locations and have been irregular and inconsistent. That has not been the case across the rest of the Corn Belt. Though the region has dealt with flooding and occasional bouts of severe weather, the overall rainfall picture has been much improved.

Michigan especially has benefited greatly from the increased rainfall. Stuck in D1-D2 drought classification (Moderate to Severe drought) on the Drought Monitor as late as June 22, the repeated rainfall during the past couple of weeks has cut almost all notes of dryness across that state out of the picture.

But areas in the northwestern Corn Belt continue to suffer under the dryness and drought. Crop conditions have been declining across the Dakotas and Minnesota. It may be too late for wheat, but as corn and soybeans are getting closer to and into their respective reproductive phases, the outlook for precipitation is on everyone's radar, pun intended.

So as we look at the rest of July and August, I talked about the potential for rainfall across the Corn Belt with DTN Long Range Team Lead Nathan Hamblin who offered some good insights as to what we might see during the next two months.

In the short-term, the pattern we have been seeing during the last month looks to continue. With weak to non-existent forcing from our biggest climate drivers, El Nino/La Nina and tropical thunderstorms in the Eastern Hemisphere, there is not much to persuade the major air masses to move anytime soon. According to Hamblin, "The next 10 days are likely to see eastern sections of the Midwest be targeted for additional rainfall. Any rains that occur across the Northern Plains should be along fronts and scattered in nature."

Hamblin said that because of the weak climate indicators, there is uncertainty in the forecast, especially as we go into the last week of July. "I would anticipate a drier Midwest pattern during the day 10-15 period (third full week of July) with the best chances for beneficial rains across the Four Corners/southern Rockies area. This pattern should not persist and a return of rains to the Midwest should gradually ramp up toward the closing days of July."

But a big change is in store as we get into the front half of August. While Pacific Ocean temperatures will likely remain neutral, the tropical thunderstorm clusters in the Eastern Hemisphere will likely gain their influence back to the U.S. weather pattern. If the signal is strong, it could lead to a flip in the temperatures, but the rainfall pattern may not go the way those in the Western Corn Belt hope. "More ridging is possible across the Eastern U.S. with a weakening of the Western U.S. heat dome," Hamblin said. "This should open up the opportunity for higher risks of rain for all of the Midwest as warmer air and Gulf moisture is drawn northward. However, the best chances lie across the Mississippi Valley areas and points eastward and some of the rain could be excessive in such a pattern. The Dakotas have a better chance of seeing beneficial rains, but these rains could be hit-and-miss compared to areas further east."

If his forecast turns out to be true, while temperatures may cool down across the Western Corn Belt, the lack of widespread heavy rainfall is unlikely to reverse fortunes for those struggling with the drought. And the temperature pattern may worsen as crops are filling at the end of the month. Added Hamblin, "The second half of August is likely to see ridging retrograde back to the West. The Northern Plains would be likely to become drier again. The mean trough should be in the East and any rains should favor eastern sections of the Corn Belt."

More haves and have-nots favoring the Eastern Corn Belt with rainfall, where crops are in much better shape, continues to be the primary thought process for the primary reproductive portion of the season.

John Baranick can be reached at john.baranick@dtn.com

John Baranick