Harvest Weather Outlook Is Largely Positive
After a summer that brought intense heat and little rainfall to portions of the Midwest, Mother Nature is finally bringing relief with improved conditions this month and a positive forecast for the start of harvest.
Most of the Midwest has been cooler than normal in August, and there’s been a reversal of rainfall over the past couple of weeks. “The drier areas in the western Midwest into eastern South Dakota and eastern Nebraska have gotten a little wetter over the past two to three weeks, says Dan Hicks, meteorologist at Freese-Notis Weather. “On the other hand, some areas east of the Mississippi River that had been wetter in June and July saw less rainfall during that time. We are seeing a shift of the heavier summer rains to the western Midwest and less farther to the east.”
The systems that have moved through during the first part of August should help alleviate drought conditions that have worsened this summer. For example, in Iowa, at this point the state has above-normal rainfall for August, according to Hicks. While the drought monitor is still scorched with orange to dark red (indicating drought conditions ranging from severe to exceptional), this will most likely improve when the new one is released on Thursday.
“The cutoff time for data for the last report was August 15, so there has been a substantial amount of rainfall after that date,” explains Hicks. “I think drought conditions will lessen in Iowa, northeastern Missouri, eastern Nebraska, and the Dakotas.”
In the eastern Midwest, there could be slight increases in the areas that have missed rains this month, but overall, Hicks predicts the worst areas will see improvement.
For the next week, after the current system moves out, a large portion of the Midwest will return to dry conditions. The exception to this will be the Plains states, Delta, and Southeast where a more active weather pattern will bring greater chances for rain.
Start of Harvest
The majority of the Midwest should see normal to below-normal rainfall for September with no major delays for harvest, says Hicks.
“However, the northern Plains will have closer to normal precipitation,” he says, adding that this could produce more delays for this region. But it should also be beneficial by continuing to “whittle away at drought conditions.”
Temperatures in the northern Plains will be a few degrees above normal moving into next month. The rest of the Midwest, stretching from the southeastern Plains through the Ohio Valley, will most likely be a few degrees below normal.
While temperatures will be trending slightly lower, Hicks isn’t sure whether or not this will mean an earlier freeze. To get a better feel for this fall, he looks back to two comparison years.
The first – 2006 – compares pretty well to this year, although there has been a divergence this month with 2017’s cooler and wetter conditions. In 2006, there were freezing temperatures earlier than normal in the Dakotas, Minnesota, Wisconsin, and parts of Iowa and Nebraska (around September 20).
The second year that is similar to 2017 is 1977 when the warmest conditions also favored the western Midwest with a cooler August. In 1977, the first freeze of the season was later than normal even in the Dakotas and Minnesota. As you can see, these two comparison years have conflicting signals.
“If these air masses keep coming down, eventually we’ll get some low-30s in the Northern areas,” says Hicks. However, this early on, it’s difficult to pinpoint when the first freeze of the season will be.