Midwest Weekly Highlights - July 25-31, 2017

---

Heavy Rain Slides South

Heavy rain fell across Missouri, southern Illinois and eastern Kentucky during the last week of July (Figure 1).  Many of these areas received more than two inches of rain, with parts of western Missouri receiving more than four inches.  Several stations in Lafayette, Cass, Jackson and Clay counties, MO had more than six inches.  Dozens of daily precipitation records fell across the southern Midwest (Figure 2).  Meanwhile, the northern half of the region was much drier.  Most of Iowa, Minnesota, Wisconsin, Michigan, Indiana and Ohio had less than half the normal amount of precipitation (Figure 3).  Fewer thunderstorms during the week also led to only a handful of severe weather reports (Figure 4). However, an EF-0 tornado on July 26 was surveyed near DeWitt, IA (Clinton County).
 

Cooler

Temperatures were below normal across a large portion of the Midwest (Figure 5).  Most of Ohio and Indiana were 2-4°F below normal, while Illinois, Iowa, northern Missouri, southern Wisconsin and southern Lower Michigan were 1-3°F below normal.  Northern Minnesota was the only warm spot during the week, with temperature 1-4°F above normal.
 

Flooding Slowly Recedes

Thanks to a reprieve from heavy rain in Wisconsin, Iowa and northern Illinois, rivers and streams were able to recede from moderate and major flood stage (Figure 6).  Major flooding persisted during most of the week on the Rock and Des Plaines rivers in northern Illinois, while moderate and minor flooding quickly receded along the Pecatonica River in southwest Wisconsin.  Minor flooding also occurred along the Mississippi River in southern Iowa.  Moderate flooding also briefly occurred in western Missouri from heavy rainfall on July 26 through the morning of July 27 (Figure 7).
 

Drought Worsens in Western Iowa

A continued lack of rainfall in western and south-central Iowa led to the expansion of moderate drought according to the July 25 U.S. Drought Monitor (Figure 8).  Nearly 35 percent of the state was considered to be in drought.  In addition, severe drought was added to several counties in south-central Iowa.  Over one million people in Iowa were estimated to be living in drought affected areas.  Rainfall in western and southern Iowa has been well below normal this summer, with many areas receiving less than half the normal amount since June 1 (Figure 9).

-BJP-