Midwest Weekly Highlights - December 15-21, 2005

---

A Quiet but Cold Week

Colder than normal weather continued through the third week of December, with the largest departures from normal remaining across the central Midwest. The only area with temperatures above normal this week was the Michigan Upper Peninsula, where temperatures were near to slightly above normal (Figure 1).  Temperatures were 8°F to 10°F below normal from western Ohio westward through the northern half of Indiana and Illinois,  and the southern half of Wisconsin, Minnesota, and much if Iowa.  This coincided with some of the deepest snow cover in the Midwest (Figure 2). The southern extent of the snow cover also remained above normal for this period (Figure 3).

While there was occasional snow, precipitation was well below normal across the southern two-thirds of the Midwest (Figure 4), and drought conditions were unchanged over Illinois, Iowa, and southern Wisconsin (Figure 5).  On December 15, a low pressure system moving through the Gulf States combined with a system moving through the Great Lakes (Figure 6) produced snow across eastern Indiana and western Ohio.  Four to six inches of snow accumulated in southwestern Ohio from this system (Figure 7, NWS Wilmington, OH ).  In addition to Ohio, snowfall and precipitation were both well above normal across Minnesota and Wisconsin as fast moving weather systems brought occasional snows (Figure 8).  Lake-effect snows were frequent as cold air streamed over the open waters of the Great Lakes.   Some locations in Ashtabula County, OH piled up more than 17 inches of lake-effect snow December 19-20.  


SDH