Midwest Weekly Highlights - November 22-30, 2003

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A First Taste of Winter

November was a generally wet month across the Midwest (Figure 1) as a progressive upper air weather pattern brought a series of weather systems through the region.  The exceptions were much of Minnesota and western Missouri, where precipitation was less than 75 percent of normal.  Temperatures this month ranged from 4F below normal in northwestern Minnesota to 4F above normal in Ohio (Figure 2).

The precipitation pattern the last nine days of November varied quite a bit across the Midwest (Figure 3), and temperatures ranged from 3F to 4F below normal in the west to 3F above normal in the eastern Midwest (Figure 4). The period began with a low pressure system developing over Colorado on November 22 (Figure 5, NOAA/HPC).  Strong southwesterly flow ahead of this system pulled very warm and moist air into the Midwest. Temperatures were as much as 15F above normal ahead of the system (Figure 6) and a few record high temperatures were set (Alpena, MI 63F, old record 59 in 1999; Paducah, KY, 72F, old record 71F in 1999). By the morning of November 23 the low was located over the lower Great Lakes. Heavy rain fell in the warm air ahead of this system.  Record daily rainfall amounts were set in Green Bay, WI with 1.54 inches (old record 1.50 inches in 1999); in Madison, WI with 1.70 inches (old record 1.60 inches in 1874); Grand Rapids, MI with 0.71 inches (old record .44 inches in 1974); and South Bend, IN with 1.03 inches (old record 0.86 in 1970). The low underwent rapid intensification in the next 24 hours, and by the morning of November 24 the intense low was centered over the northeast shore of Lake Superior with a cold front trailing through eastern Ohio southward into the Gulf of Mexico (Figure 7, NOAA/HPC). Snow fell across the upper Midwest, with as much as 16 inches in Superior, MN, and 8 to 12 inches of snow covered much of northern Minnesota into northwestern Wisconsin (Figure 8).  As cold air spilled south behind the cold front many locations in the central Midwest struggled to climb out of the 20s after several days in the balmy 60s.  The first subzero temperatures of the season were recorded across northern Minnesota on the morning of November 25 (Figure 9, Unisys).  Hibbing, MN reported -10F; Eveleth, MN, -9F; and International Falls, MN -7F.

Another low pressure system moved through the lower Midwest on November 26-27, bringing more rain to southern Missouri, southern Illinois, Indiana, and most of Kentucky and Ohio.  The heaviest rain, 1.00 to 1.50 inches, fell in a band from western Kentucky through southeastern Indiana into western Ohio (Figure 10).

Snow showers and flurries developed in the cold, cyclonic flow behind this system, and holiday shoppers on the Friday after Thanksgiving had to cope with slippery roads in much of eastern Illinois, Indiana, and Michigan. Thunder and lightning was even observed with some of these snow showers by a MRCC staff member in northeastern Illinois during the evening of November 28 (Figure 11, NWS).

November ended with a warm-up across much of the Midwest on November 29 and 30. By November 30 high temperatures had rebounded into the low 60s across southern Missouri, the upper 50s as far north as Illinois and Indiana, and into the 40s across the upper Midwest (Figure 12, Unisys).  Snow cover over northern Minnesota and Wisconsin prevented temperatures from warming past the mid 30s.