Midwest Overview - November 2009

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Warm Temperatures

November saw a reversal of the temperature pattern seen in October with above normal temperatures across the Midwest. Departures from normal ranged from 1°F in southeast Kentucky to 11°F in northwest Minnesota (Figure 1). Preliminary figures for the Midwest rank the month as the 5th warmest in the past 115 years following an October that ranked as the 7th coldest over the same time period. Southwest Minnesota saw the biggest swing from 7°F below normal in October to 10°F above normal in November. During the month, more than 400 record high minimum temperatures and 200 record high maximum temperatures were set. On the other hand, just a handful of record lows were recorded.
 

Precipitation

Following a wet October, November precipitation was light with most of the Midwest below normal (Figure 2). Two swaths of less than 50% of normal were evident. The first extended across southern Minnesota, the northern two-thirds of Wisconsin, and most of the upper peninsula of Michigan. The second included extreme southern Missouri and Illinois, Kentucky, Ohio, and most of Indiana and lower Michigan. Above normal precipitation was limited to a narrow swath across extreme northern Missouri and central Illinois and a small area of northern Minnesota.

The first two weeks of November were particularly dry with rainfall totaling less than an inch across the nine-state region (Figure 3). This represented less than 50% of normal precipitation everywhere except northern Minnesota. Most of the month's precipitation was associated with one of two storms. The first was a cutoff low that lingered over Missouri for several days before kicking out across Lake Michigan (Figure 4). The second was a system that moved across the Midwest from west to east over the Thanksgiving holiday bring a mix of rain and snow to parts of the Midwest (Figure 5). Flooding was reported throughout the month along the lower Illinois River (Figure 6). Rain during week three caused short-lived flooding in Iowa, Missouri, and Illinois.
 

Fall Temperature Extremes

Temperatures for the fall season were near normal (within 2°F of normal) across most of the Midwest. Above normal temperatures were recorded in upper Michigan, northern Wisconsin, and northern Minnesota with the largest departures reaching 5°F above normal in northwest Minnesota (Figure 7). Breaking the season down by month gives a very different impression of the month with October well below normal and November well above normal. The table below shows the ranks for each month and state. Ranks range from 1 (warmest on record) to 115 (coldest on record) for the past 115 years with extreme ranks (top and bottom 15) in color.

	Temperature Ranks (1=Warmest, 115=Coolest)
State		Sep	Oct	Nov	Sep-Nov
IL		75	109	7	60
IN		59	102	9	56
IA		59	113	3	52
KY		51	105	18	66
MI		33	103	6	39
MN		6	111	3	15
MO		85	111	7	76
OH		63	102	10	50
WI		16	107	2	24
Midwest		39	109	5	43

 

Fall Precipitation Extremes

Fall precipitation varied from just under 75% of normal near the Great Lakes to nearly 200% of normal around St. Louis and in west central Minnesota (Figure 8). Precipitation totals for the season ranged from less than 5 inches in northern Minnesota to more than 21 inches in southern Missouri (Figure 9). Though not as extreme as the temperatures, the monthly precipitation values ranked from some of the driest to some of the wettest on record. The table shows the monthly precipitation ranks for each state. Ranks range from the wettest (1) to the driest (115) with extreme ranks in color.

	Precipitation Ranks (1=Wettest, 115=Driest)
State		Sep	Oct	Nov	Sep-Nov
IL		92	2	59	12
IN		65	5	99	31
IA		101	1	67	31
KY		11	3	113	25
MI		109	5	107	67
MN		104	3	78	32
MO		63	2	68	6
OH		61	17	111	69
WI		112	3	105	70
Midwest		100	1	96	26

 

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