To say that many parts of the state have experienced a wet stretch of weather would be an understatement. Heavy rainfall has left a wide variety of negative crop conditions, from yellowing in soybean fields where ponding has been persistent to highly variable heights on corn stands, delayed wheat harvest and hay cutting. With all of this rain, streams and rivers have been running much above normal as well. But how historic is our recent rainfall?
Table 1 shows accumulated precipitation for May through July 2017 for selected stations* around the state, one from each of Ohio’s 10 climate divisions where the greatest precipitation occurred, along with their departures from normal conditions (based on the 1981-2010 period), single 1-day maximum precipitation events, and their dates of occurrence. Totals range from 14.41” at Cleveland-Hopkins International Airport in the Northeast division to as much as 23.01” in Lima (Northwest division). This small sample of results shows just how heterogeneous precipitation can be, especially during summer when localized heavy rainfall occurs in thunderstorms that move over particular regions.
TABLE 1. May-July 2017 Precipitation+
+ Precipitation values through July 30, 2017. No precipitation expected on July 31.
The departures from normal vary widely as well, with areas from central Ohio to the north and west picking up between 5-11” of above normal rainfall. Climatologically, northern Ohio experiences slightly less rainfall than southern Ohio for the period. It is not surprising then that with 23” of rain, Lima reported a whopping 10.85” of surplus rainfall while South Point in southern Lawrence County (17.01” of rainfall) was only 2.45” above normal. Many of these stations reported single-day totals over 3” as well. According to CoCoRaHS reports (a community-based network of volunteers; https://cocorahs.org/), three sites in Ohio experienced events of more than 5” during the period (in Brown, Fayette, and Scioto Counties).
Figure 1 shows the rankings for each climate division (average of all the stations within each division) for May-July 2017 compared to the last 123 years (1895-2017). Seven of Ohio’s ten climate divisions experienced one of their top ten wettest May-July periods on record, with the Central, West Central, and Northwest divisions cracking the top 5. For the West Central division, only 1958 and 2003 had greater precipitation totals while for the Central division, this year beat out all years except 1990 and 1958.
One final note, while most of the state has experienced wet conditions, a few locations have managed to escape the worst of it. Portions of Summit, Portage, and northern Stark Counties are running about 75% of normal precipitation over the last 60 days. However, even these areas are not likely to develop drought conditions in the near-term.
Figure 1: Climate division ranks for precipitation for the period May-July 2017 compared to the 123 year record (1895-2017).
Data for this analysis originates from NOAA’s National Centers for Environmental Information (NCEI) Climate Division dataset (https://www.ncdc.noaa.gov/monitoring-references/maps/us-climate-divisions.php) and was obtained from the Midwest Regional Climate Center (http://mrcc.isws.illinois.edu/).
*Stations used had more than 98% of the data reported for this period and long-term means for historical perspective. Additional stations not included may have received greater precipitation totals for this period.
For more information on the weekly hydrologic conditions and climate outlook from the State Climate Office of Ohio, visit http://climate.osu.edu.