Midwest Weekly Highlights - May 22-31, 2015

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Wet Week

Above normal precipitation was common across most of the Mississippi River Valley and Great Lakes this week (Figure 1) as the wet month of May came to an end. Two or more inches of rainfall fell across Wisconsin, Illinois, Michigan, eastern Iowa, and northern Iowa and Indiana (Figure 2).  Despite lower totals in Minnesota — around one inch — precipitation was still above normal for the period across most of the state.  The driest patches this week were across the Ohio Valley.  Western Kentucky received precipitation totals of an inch below normal with the rest of the Ohio Valley mainly a half inch below normal (Figure 3).
 

Just A Bit Warm

While most of the region was within 3 degrees of normal to end the month, a majority of the region leaned to the warm side (Figure 4).  The warmest spots were seen in the eastern reaches of the region.  Most of Indiana and Michigan were 2-5°F above normal while most of Ohio was 4-6°F above normal.  Along the western edges of the region, some slightly below normal temperatures were seen, but most of Minnesota, Iowa and Missouri were within a degree of normal.
 

Another Wild Week of Severe Weather

The active severe weather month of May continued as seven of the ten days over the period brought severe weather reports to the region (Figure 5).  May 24th brought a few tornadoes to Missouri and southwest Iowa, with two EF-1 tornadoes touching down in southwest Missouri.  Storms on the western fringes of Iowa and Missouri brought a few hail reports the next day while strong storms pummeled Texas and Oklahoma.

Storms largely shifted eastward on May 26-27th, as western Ohio and central Kentucky dealt with strong winds while several tornadoes touched down.  An EF-1 tornado moved through northwest Illinois while an EF-0 tornado hit just south of Chicago.  Another EF-1 tornado also paraded through southwest Ohio.  On the 27th, a cluster of storms producing high winds hit northern Indiana and Ohio, as well as southeast Michigan, with many of the reports along the Lake Erie shoreline.

Storms quieted on May 28-29th, but two reports of two-inch diameter hail were seen in Lake of the Woods County, MN and Dickinson County, MI.  Strong storms returned in force on May 30th across the Ohio Valley.  Strong winds knocked down trees all along the valley.  In Simpson County, KY, a tree fell on a Relay for Life event that injured six people.  An EF-1 tornado also touched down later that night just southeast of Indianapolis.

In all, ten tornadoes were reported across the region for the period, with a couple dozen hail reports and well over one hundred wind reports.
 

Drought Continues to Improve in Minnesota & Wisconsin

Above normal precipitation continued to end the month in Minnesota and Wisconsin, cutting drought conditions from both states in the latest Regional Drought Monitor (Figure 6).  Only a quarter of Minnesota is now classified in moderate drought, while drought conditions were alleviated across 30% of Wisconsin.  This marks the second consecutive week of drought reduction for the region, as the month of May was decidedly wet for the Upper Midwest (Figure 7).

-BJP-