Rainy Start to October
Precipitation was at least 200% of normal for a large portion of all Midwest states during the first week of October with the exception of Missouri and Illinois (Figure 1). The largest departures of 500% to 750% of normal were found along the Ohio River in southern Indiana and southwest Ohio, where weekly precipitation totals ranged from 3" to 5" (Figure 2). Weekly precipitation totals greater than 1.5" spanned across the upper Midwest and across the Ohio River Valley. Much of the precipitation in the Ohio River Valley came during an event that moved through the region on October 5th and 6th
(Figure 3). The first week of October also brought some much needed rain to areas of Minnesota, with impressive three day totals in some locations from October 2nd-5th. Areas with below normal precipitation during the first week of October include much of Missouri and northern Minnesota, where precipitation ranged from only 0.2" to 0.75".
Unseasonably Warm Start to October
Average temperatures were above normal for a majority of the Midwest during the first week of October (Figure 4). The highest temperature departures of at least 9°F above normal were mainly in Ohio, but extended into eastern Indiana, southern Michigan, eastern Illinois, and northeastern Kentucky as well. Temperatures were within a degree or two of normal along the western edge of the region. Minimum temperatures were quite a bit above normal, with departures of 12°F to 14°F stretching across the Ohio River Valley
Drought continues to affect 5 out of the 9 Midwest states according to the October 8th release of the US Drought Monitor (Figure 6). The highest level of drought in the region at the current time is extreme drought (D3), which is affecting a small portion of central Iowa. In all other levels of drought, there was a slight improvement from last week. Currently, around 10% of the region is in severe drought (D2) and just over 16% is in moderate drought (D1), compared to 11% and 19% last week, respectively.
Severe Weather, Including Tornadoes
After a quiet end to September in terms of severe weather, the beginning of October brought quite a few severe weather reports, including 10 late-season tornado reports
(Figure 7). The tornado reports came from Iowa on the 4th, in the towns of Sloan (Woodbury County), Hinton (Plymouth County), Moville (Woodbury County), Cherokee (Cherokee County), and Quimby (Cherokee County). A half-mile to a mile wide tornado was reported, with associated structure damage reported as well. The remaining tornado reports occurred a day later on the 5th in Wisconsin, in the towns of Endeavor and Packwaukee, both in Marquette County. Multiple funnel clouds were reported in Wisconsin, as well as debris on roadways and fallen trees.
The Minnesota State Climatology Office also contributed to this report.