Source: Ohio State University

After a dry late summer and autumn of 2022, winter turned wetter to offset that dry period. However, in April 2023, we turned a bit drier again. The main thing we need to monitor closely now is a rapidly developing event in the eastern equatorial Pacific Ocean. It appears we are on our way toward an El Niño very soon.

There are two types of El Niño events, ones in the eastern equatorial Pacific near South America (almost directly south of Ohio) and the other in the central equatorial Pacific Ocean more south of Hawaii. It appears this one may be an eastern Pacific type. Historic years with the eastern Pacific developing El Niño (EPAC) include 1957, 1965, 1972, 1982, 1997 and 2015. 

The following images are what happens from May to August in those developing eastern Pacific El Niño years since 1950 for temperatures and precipitation. In those summer growing seasons, it tends to be normal temperatures (with limited extreme maximum temperatures above 95) with a tendency toward drier than normal conditions. The wheat areas of the Plains and western corn and soybean areas tend to see wetter conditions while eastern corn and soybean areas tend to be drier.

The Midwest Regional Climate Center at Purdue has a great page with crop yields impact related to these developing El Niño events. Most of the EPAC El Niño years had below normal trend line yields in Ohio. It is not a guarantee this would happen this year yet as things are developing at this time. We should know more in a month or so.

https://mrcc.purdue.edu/mw_climate/elNino/impacts.jsp

OUTLOOKS:

The outlook for the rest of May includes near normal temperatures with precipitation near normal in southern Ohio and below normal in northern Ohio.

The latest U.S. climate model indicates a drier June and August and a near normal July for rainfall.

https://www.cpc.ncep.noaa.gov/products/CFSv2/htmls/usPrece3Mon.html

Looking ahead to autumn harvest season, the normal temperature pattern and normal to below normal rainfall trends are expected to linger through October before wetter conditions may arrive late in the harvest season about November. The other indication is freeze and frost conditions do not look likely in September but could occur at or earlier than normal in October based on projected El Niño conditions.

https://www.cpc.ncep.noaa.gov/products/CFSv2/htmls/usT2me3Mon.html

In summary, it appears an El Niño is coming very soon and could have some negative impacts to Ohio. Monitor for areas of developing dry conditions into June.