Midwest Weekly Highlights - January 8-14, 2015

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Cold Lingers into Second Week

Average temperatures during the second week of January were below freezing for the entire region.  Northern Minnesota and northern Wisconsin were coldest with average temperatures 5 to 9°F below zero, with the southern fringes of Missouri, Illinois, Ohio, and much of Kentucky warming to average temperatures of only 20-25°F (Figure 1). A large majority of the region experienced colder than normal temperatures with average temperatures 9 to 16°F below average with the coldest pockets of air over north-central Wisconsin, northern Indiana/southern Michigan, and northwest Ohio (Figure 2). Average maximum temperatures ranged from 5°F in northern Minnesota to 30°F and warmer upon reaching the immediate Ohio River Valley and the southern two-thirds of Missouri.  Average minimum temperatures ranged from 9°F below to 20°F below freezing across Minnesota and Wisconsin, while only warming to 15°F across much of the southern portions of the region.  Minimum temperature departures from mean contributed more greatly to the colder mean temperatures experienced during the second week (Figure 3).
 

Snowfall across North, Wintry Mix with Ice aross Ohio River Valley

Accumulated precipitation varied from 0.10” to 0.75” across the region with isolated pockets of 0.75” to 1.0” in the vicinity of Lake Erie and Lake of the Woods Minnesota.  A dry tongue of little to no precipitation (amounts of 0.0” to 0.1”) resided over the west-central portion of the region (southwest half of Minnesota, all of Iowa, and northwest Missouri) (Figure 4). Much of the region, however, remains below normal for accumulated precipitation with only small pockets of accumulated precipitation near 100% of mean in southern Illinois, north-central Indiana and northern Ohio due to a storm system that moved across the lower Midwest on January 11, 2015.  Other locations having 75-125% of mean accumulated precipitation are in northwest Wisconsin, portions of Michigan, and northern Minnesota (Figure 5). Snowfall accumulation remained confined to the northern states, and the northern portions of Illinois, Indiana, and Ohio (Figure 6), with remaining areas seeing 0.0” to 2.0”snowfall deficits (Figure 7).

The winter storm that moved across the southern portion of the region January 11th and 12th primarily impacted the states of Illinois, Indiana, and Ohio.  The Indianapolis National Weather Service had issued ice storm warnings for the event anticipating 0.25” ice accumulation.  Reports came in with 0.1-0.2” of ice accumulation. 
 

-OBK-