Midwest Weekly Highlights - March 15-21, 2015

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Drier Week

After flooding took the headlines last week, a much drier weather pattern took over this week, leading to below normal precipitation across the Midwest (Figure 1).  All but parts of western Missouri and eastern Kentucky saw less than half an inch of precipitation (Figure 2).  Most of Wisconsin, southern Minnesota & Michigan, northern Indiana & Illinois, and all of Iowa went completely dry.  Fortunately, the area most below normal this week was along the Ohio River, which helped lower river stages.  Snow this week was very sparse and limited to northern Minnesota and the U.P. of Michigan as temperatures were too warm in most cases (Figure 3).
 

Warm Temperatures Stick Around

Mild spring temperatures continued across the Midwest this week as above normal mean temperatures stayed in the region another week (Figure 4).  The most above normal areas were once again located in southern Minnesota and western Iowa, where temperatures were 8-12°F above normal.  Northern Minnesota and Wisconsin also stayed warm at 6-9°F above normal.  The rest of the region was closer to seasonal norms this week at 0-5°F above normal.  Afternoon high temperatures had a lot to do with the above normal mean temperatures, as highs across southern Minnesota, Wisconsin and Iowa averaged in the 50s to low 60s (Figure 5).
 

Waters Receding

Thanks to below normal precipitation and thawed soil, the Ohio River and its tributaries receded below flood stage in the eastern half of the Ohio Valley this week.  Flood warnings slowly ended from Cincinnati through Louisville on the Ohio River as the week progressed.  The Wabash River also continued to recede north of Washington, Indiana.  Flood warnings still exist, however, from southwest Indiana to the mouth of the Ohio River and along the Mississippi River along the Missouri Bootheel.
 

Drought Expands in Minnesota, Moves into Western Wisconsin

As demand for water rises as soils thaw this spring, so has the concern for drought in the Upper Midwest as below normal precipitation has fallen since the start of winter (Figure 6).  The National Drought Mitigation Center’s most recent update has most of Minnesota and parts of northwest Wisconsin in the moderate drought category (Figure 7).  Adding insult to injury, NOAA’s recently released Spring 2015 Outlook shows an elevated chance of below normal precipitation this spring (Figure 8).  Drought is also expected to form across most of Wisconsin and worsen across Minnesota as spring rolls along (Figure 9).

-BJP-