November 8-14, 2005
Midwest Weekly Highlights - November 8-14, 2005
Another November Severe Weather Outbreak
During the week of November 8-14, conditions were once
again reminiscent of spring, with fast moving weather
systems and a strong north/south temperature gradient.
The ingredients for severe weather were most strongly
present on the 12th, when a tornado outbreak in central
Iowa claimed a life (Figure 1, College of DuPage - COD).
Despite the fast moving weather systems, most were dry,
and only northern parts of Minnesota and Wisconsin,
central Lower Michigan, and southeastern Ohio received
more than 1 inch of precipitation for the week (Figure 2).
Most of the Midwest received less than 50% of normal
precipitation, including the core drought region in eastern
Iowa and Illinois (Figure 3). Temperatures were 6-12°F
above normal throughout almost the entire region (Figure 4),
and the lack of severe cold was keeping grass growing
longer than normal in the late fall.
Warm and Windy Start to the Week
A strong low pressure center entered northern Minnesota from the Dakotas on the 8th and intensified to a very low central pressure (Figure 5, COD). Ahead of the low, many high temperature records were set in the region as a strong influx of warm air arrived from the southwest. In Missouri, St. Louis (82°F) and Vichy/Rolla (79°F) set new high temperature records, while Kansas City and Columbia tied records. Further east, Paducah, KY, not only set a new daily temperature record with 83°F, but also tied the high temperature record for all of November. Also in Kentucky, Bowling Green (82°F) and Jackson (80°F) set new records, and several other places tied old records. The high temperature map for the 8th looked more like early September than mid-November (Figure 6, Unisys). Paducah and Jackson also set new high temperature records on the 9th, 77°F and 80°F, respectively.
High winds really took off on the 9th, as the low center
moved north of the Great Lakes and intensified further.
Sustained winds greater than 30 mph were common in the
northern Midwest, and gusts reached over 50 in
Minnesota, Wisconsin, and Michigan. The winds at
Stannard Rock on Lake Superior reached 71 mph, and a
ship reported a gust of 74 mph, one day before the 30th
anniversary of the loss of the lake freighter Edmund
Fitzgerald. On land, Houghton, MI, recorded a gust of 66
mph, and Glenwood, MN, reported a wind gust of 58 mph.
From Duluth, MN, and Green Bay, WI, in the northwest,
to Flint, MI, in the southeast, many locations reported high
winds over 50 mph and non-thunderstorm wind damage,
including scattered power outages.
Intense Tornado Outbreak in Central Iowa
The days after the windstorm were dominated by high pressure, and southerly breezes returned warm air to most of the Midwest. High temperature records were set on the 11th in Minnesota at the Twin Cities (64°F) and several other locations all the way north to International Falls. The 12th started warm throughout the Midwest, with high temperatures for the day in the 60s and 70s except in the very northernmost tier of the Midwest. A strong upper level trough entered the region (Figure 7, COD) during the day, with a strong jet stream above warm, moist surface breezes providing excellent support for severe weather development. A very strong low pressure center moved northeast from the central Plains through Minnesota (Figure 8, COD), bringing a tongue of high dew point air northward into Iowa (Figure 9, COD). An initial line of thunderstorms quickly moved away from the center and brought strong but not severe thunderstorms to Wisconsin and Illinois (Figure 10, COD). However, a second and much more dangerous line of storms formed near the low pressure center where warm, moist air was forced aloft by cold air wrapping around the low. These storms in central Iowa (Figure 1, COD) produced several families of tornadoes with 24 tornado reports north of Des Moines, as well as several isolated tornadoes elsewhere (Figure 11, Storm Prediction Center - SPC).
The storms occurred within a tornado watch box (Figure 12, SPC), and were well warned (Figure 13, SPC). The combination of good warnings, and the occurrence of the storms late in the day and early evening hours led to excellent recognition by the public, and far fewer casualties than one would expect from the dozens of destroyed homes. In fact, the one fatality was sheltering in her basement in Stratford, IA, when an F3 tornado destroyed her home and collapsed the debris into the cellar hole. About 30 homes total were destroyed in Stratford and 40 were destroyed in Woodward by F2/F3 tornadoes, and several dozen people were injured. A tremendous potential tragedy was averted when a tornadic supercell traveling over Ames, IA, did not land its F2 tornado on the ground until it was just north of the city. Tens of thousands of football fans had evacuated the Iowa State University stadium and sheltered in a less than ideal position in the nearby basketball arena as the elevated funnel cloud passed overhead. A direct hit to the arena would have resulted in countless casualties. These people are Cyclone fans (the Iowa State team name), but were glad not to encounter this kind of cyclone directly.
As the low center pulled away, wind gusts of 50-70 mph were once again present in the northern Midwest, especially on Lake Superior. In addition, the first one-inch snowfalls of the season occurred in a few places across northern Minnesota and nearby parts of Wisconsin and Michigan as cold air was dragged southward behind the low. However, the cold air did not reach too far south, leaving open the possibility of still more unseasonable weather clashes in the next reporting period.