November 8-14, 2010
Midwest Weekly Highlights - November 8-14, 2010
A Swing to the Warm Side
The entire Midwest enjoyed early fall-like warmth for most of the week. In typical November fashion, however, the week ended with a major snowstorm across the northwestern portion of the region
The entire region was much warmer than normal this week, with the core of the warmth extending from the Ohio River northwestward into northern Minnesota. Temperatures departures ranged from 7°F above normal along the Ohio River to 13°F above normal in northern Minnesota (Figure 1). There was much more of a range in minimum temperature departures this week. Minimum temperatures ranged from 3°F below normal in eastern Ohio and Kentucky to 12°F above normal in northern Minnesota (Figure 2). The larger contribution to the warmth this week were the high temperatures. Clear to mostly sunny skies, southerly winds, and dry autumn air allowed temperatures to climb into the 60s and 70s the middle part of the week. The highest departures were over central Indiana, where high temperatures were 15°F to 17°F above normal (Figure 3). The peak of the warm weather occurred from November 10-13, where 262 record maximum temperatures and 82 record high minimum temperatures were set or tied.
For the first five days of the period there was very little precipitation in the region, with most locations east of the Mississippi River receiving little more than sprinkles or light showers (Figure 4). Precipitation associated with the late week storm was observed in the far southwestern portion of the region by November 12th, but until that point precipitation was well below normal. By the end of the week most of the region west of a Green Bay, WI to Springfield, MO line had received more than twice the normal weekly precipitation (Figure 5), while only light amounts were reported in the eastern two-thirds of the region. The was little change reflected in the status of drought across the Midwest in the November 9th U.S. Drought Monitor (Figure 6). The dry weather and low humidity contributed to a 400 acre fire in the Shawnee National Forest in Illinois. Officals described the fire as low intensity, burning along the ground, and that it was human-caused.
Major Snowstorm Clobbers Upper Midwest
On November 12th low pressure waves along a front in the Southern Plains were beginning to gather strength (Figure 7), and winter storm watches were posted from northwestern Iowa into northeastern Minnesota and northwestern Wisconsin (Figure 8). By noon CST on November 13th an organized low pressure system was located over northwestern Iowa, with a shield of snow occurring from Nebraska through northwestern Iowa into Minnesota (Figure 9). Snow was reported falling at a rate of 2 inches per hour at times, and accompanied by thunder and lightning. Snowfall amounts on the morning of November 13th totaled 14 inches in Emmetsburg, IA (Palo Alto County), 12 inches in Pocahontas, IA (Pocahontas County), and 7.0 to 10.0 inches in the Minneapolis-St. Paul area (Figure 10). The heavy, wet snow snapped tree limbs, which in turn brought down power lines. An estimated 150,000 households in Minnesota lost power during the storm. The Minnesota State Patrol responded to more than 350 vehicle accidents resulting in 45 injuries, and 470 reports of vehicles off the roads. The storm did slow air traffic at the Minneapolis-St. Paul airport, but the airport did not close.
The low pressure system moved only slowly northward to Lake Superior by the morning of November 14th, and another two to six inches of snow accumulated by the morning of November 14th (Figure 11) in eastern Minnesota and northwestern Wisconsin. More than two dozen locations in Iowa, Minnesota and Wisconsin set new daily snowfall records during this storm, and six locations set new all-time daily snowfall records.
-SDH-