February 2001
Temperature and Precipitation Anomalies.
February was a very interesting month climatologically, with many days of relative placid conditions interrupted every seven to nine days by huge precipitation producing systems. The Midwest experienced overall its 9th wettest February, with Missouri having its wettest in 107 years of records. Precipitation totals exceeded 200% of normal across a wide band of the Midwest from southwestern Missouri to southeastern Michigan (Figure 1). Only north-central Minnesota and much of Ohio received significantly less precipitation than normal. Snowfall for February was in the normal range over the northern and western Midwest, with some lack of snow in the Ohio River Valley (Figure 2). While the drought worries of last fall are over, some are now worried about too much rain interrupting spring field work. As is often the case with an active weather pattern in the Midwest, the western portion of the region was 2-10°F cooler than normal, while the eastern portion was 2-6°F above normal (Figure 3). Therefore, the regional average was in between, with the Midwest registering its 41st coldest February. Minnesota tied for its 14th coldest February, with Iowa close behind with its 18th coldest.
The impacts of the major system began with the snow on February 8-9 (Figure 17). Most of the snow that fell in Minnesota and western Wisconsin occurred on the 8th due to overrunning well ahead of the main low. As the low approached on the 9th, heavy snow occurred on top of a layer of freezing rain in areas northwest of the storm track, with Iowa, Minnesota, and Wisconsin feeling the brunt. The combined effect of the freezing precipitation largely immobilized transportation in Iowa, and caused lots of problems in the other areas affected by snow. Schools were closed throughout northwestern Missouri, Iowa, and southern Minnesota, with accidents commonplace despite warnings for people to stay home. The road conditions in southern Minnesota were likened to "buttered Teflon" (Minneapolis Star Tribune, 01/02/09). In Minnesota, there were 35 rollover accidents just in the Twin Cities area, including one involving a demolished $175,000 fire truck, and at least four traffic fatalities were linked to slippery road conditions. An amazing total of 2086 cars were ticketed and towed in Minneapolis, resulting in costs in excessive of $200 per car for their owners. Bitter cold air entered Minnesota after the low passed, with winds of 30-40 mph commonplace. In Iowa, several interstates, including I-80, were closed for much of the 9th due to ice and heavy, blowing snow, and non-essential state workers were told to stay home. Many stranded on highways were rescued by the State Patrol. More than 10,000 electrical customers lost power due to icing and high winds, and 1,000 rural customers had to wait more than 24-hours for power to be restored. Flights were delayed and airports closed, so that even the governor could not return from a trip to Arizona. In the warmer Quad Cities area, heavy rain caused local flooding, exacerbated by some ice jams that developed.
States in central and eastern portions of the Midwest had to contend with flooding rains and severe winds accompanying gust fronts and thunderstorms. The most severe damages were reported in Missouri and Illinois (Figure 18, Storm Predication Center). In the town of Grafton, IL, in the St. Louis area, strong winds knocked down power lines and signs and ripped the roof off a house. Trees were uprooted, and many homes had at least some roof damage. Flight activities were limited in Cincinnati as the front came through, and a small church steeple was toppled. Small power outages caused by the wind were common in the eastern Midwest, including in Illinois, Indiana, Michigan, Ohio, and Kentucky. All damage appeared to be from straight-line winds, with no tornadoes detected.
Floods occurred in two varieties, the street flooding of cities with frozen surfaces receiving 1-2 inches of rain, and the river flooding that continues in some places 4 days after the rain stopped. Many rivers in Missouri, Wisconsin, Illinois, Michigan, and Indiana have reached flood stage this week, although most stayed at that level for only a day or two (Figure 19), U.S. Geological Survey). At the end of the period, though, a number of rivers were still above flood stage. The Wabash River, in the Indiana/Illinois border region, is the largest river that is significantly above flood stage (Figure 20, USGS). Portions of Indiana Highway 43 were washed out by the Wabash. Further rains at the start of the next period may renew flooding in some areas.
The intense low pressure center that visited the region on February 24th through 26th generated sustained winds of 30 to 40 mph with gusts in excess of 50 mph at many locations. Some peak wind gusts were: 51 mph at Columbia, MO; 52 mph at St. Louis, MO; 53 mph at Cedar Rapids, IA, Toledo, OH, and Rockford, IL; 56 mph at South Bend, IN; and 58 mph at Milwaukee, WI. There were scattered reports of power outages and tree damage from the high winds. The winds combined with blowing snow hampered travel in parts of Minnesota and Wisconsin. In addition, the rains that fell exacerbated flooding conditions on some of the larger rivers in the region, including the Wabash and Illinois Rivers.