November 2010
Midwest Overview - November 2010
A Changeable Month
The first three weeks of November were characterized by wide week to week swings in temperatures and a continuation of the generally dry weather that has been ongoing most of the fall. That all changed the last nine days of the month when a series of storms systems brought heavy rain to the Ohio Valley, severe storms to the central Midwest, and heavy snow to much of Minnesota.
When all was said and done at the end of the month, temperatures for November were near to slightly above normal. Average daily temperatures ranged from near normal across the eastern third of the region to 1°F to 3°F in the eastern two-thirds (Figure 1). The higher departures were mostly in the upper Midwest. However, week to week changes in average temperatures were dramatic. During the first week of November temperatures were well above normal in the northwestern half and much below in the southeastern half (Figure 2). There was a major warm-up the second week of November and much of the region was from 7°F to 13°F above normal (Figure 3). The third week was significantly cooler (Figure 4), as was the northern third of the Midwest the last nine days of the month (Figure 5).
Heavy Rain Breaks Back of Ohio Valley Drought
November precipitation was variable across the region. Precipitation was above normal from southeastern Missouri through Ohio, and 150 percent of normal from southern Indiana to southwestern Ohio (Figure 6). Most of this precipitation came during the last nine days of the month (Figure 7), and resulted in a significant improvement in the Severe to Extreme Drought in the Ohio Valley. Normal to above normal precipitation will be needed in the coming months to further eradicate the dry conditions, however. Precipitation was also near to above normal in a narrow band from southwestern Iowa to northeastern Minnesota. In southwestern Minnesota and from northern Missouri into northern Lower Michigan precipitation was about 50 percent of normal.
An Early Start to Heavy Snow in Upper Midwest
Significant snowfall in November was generally limited to an area from northwestern Iowa through the northwestern half of Minnesota, although there was some lake-effect snow in Michigan. Snowfall totals exceeded two feet in the far north, with a significant portion of the monthly total coming the last few days of the month (Figure 8). Snowfall in northern Minnesota was generally 150 to 200 percent of normal for the month. At the end of the month four or more inches of snow covered the ground over much of the northern half of Minnesota, extreme northwestern Wisconsin, and the western U. P. of Michigan (Figure 9).
November Tornadoes
Severe weather occurred on November 22nd as a strong cold front swept through the Midwest (Figure 10). Tornadoes touched down in northern Illinois and southeastern Wisconsin causing minor to moderate damage and three injuries. A few severe storms occurred later in the week in Missouri and Indiana, including four tornadoes reported in Missouri (Figure 11).
Autumn Season is Slightly Warm, Variably Wet
The fall (September, October, November) temperature departures in the Midwest were near to just slightly above normal across the region (Figure 12). Warm, dry weather particularly in September and October aided an early completion to harvest across most of the region. The northwestern half of the region was consistently wetter than the southeastern half during September and October (Figure 13), while drought worsened in the Ohio Valley. Heavy rain in late November helped knock down the precipitation deficit in the southern Midwest and Ohio Valley and mitigating the drought. For the season precipitation was near to above normal west of the Mississippi River, and much above normal across Minnesota, the northern half of Wisconsin, and the Michigan U. P. (Figure 14). Precipitation across the remainder of the region was 75 percent to 90 percent of normal for the season.
-SDH-