Midwest Overview - November 2008
Warm Start, Wintry End
After a very warm start, the month of November ended with cold, snowy weather hampering travel for those returning from the long Thanksgiving weekend.
Temperatures the first week of the month could best be described as balmy, with highs in the 70s across much of the region. There were five consecutive days where high temperature records were set in the Midwest during the first week, and temperatures ranged from 3°F above normal in southeastern Kentucky to more than 14°F above normal in northern Minnesota (Figure 1). The remainder of the month, however, was a different story. Temperatures the last three weeks of the month ranged from near normal in northwestern Minnesota to 7°F below normal in Kentucky (Figure 2). When all was said and done, November temperature departures ranged from 3°F above normal in northern Minnesota to 5°F below normal in southeastern Kentucky (Figure 3).
A persistent band of northwesterly winds aloft over the Midwest kept much of the region dry during the month. The heaviest precipitation was in the western portions of the region on the southern edge of the northwesterlies, and in the lake-effect snow areas. Frequent cold frontal passages, followed by westerly and northwesterly surface winds bringing cold air over the relatively warm lake waters produced frequent days with lake-effect snow. The heaviest lake-effect snow fell between November 17 and November 23. Winds veering into the northwest behind a departing storm system on November 30 brought heavier lake-enhanced snow to Michigan. Precipitation during for the month of November was above normal in northwestern Minnesota, central Iowa, and downwind of the Great Lakes in Michigan and northeastern Ohio (Figure 4). Elsewhere, precipitation was only from 50 to 75 percent of normal, with an area from southern Missouri through central Illinois with less than 50 percent of normal precipitation.
Areas of drought in the upper Midwest and in Kentucky expanded during November. This marks the fourth consecutive month that most of Kentucky has been dry, although some parts of northern Kentucky have had below normal rainfall since the spring. Extreme drought conditions continued over eastern Kentucky where November precipitation was 70% of normal. Eastern Kentucky communities such as Jackson and London are short roughly a foot of rain for the year-to-date which makes 2008 potentially one of the driest years on record for this region. Drought conditions ease somewhat towards western Kentucky but many areas remain in moderate to severe drought.
Fall 2008 Temperatures Near Normal
Temperature departures were within 1.5°F of normal across most of the Midwest during climatological fall (September through November), with departures of +1.5° in northern Minnesota and -1.5° in southern Missouri and Kentucky (Figure 5). Precipitation was 150 to 200 percent of normal in northwestern Minnesota and from northeastern Missouri northeast into southern Michigan (Figure 6). The high precipitation in the central Midwest was largely due to heavy rain in September from the remnants of Hurricanes Gustav and Ike. In northwestern Minnesota precipitation was much above normal all three fall months. Dry areas were central Wisconsin and the Ohio Valley, where fall season precipitation was 50 to 60 percent of normal.
For more details on weather and climate events during November 2008, click on the individual weekly report links on the upper right.