September 2001
Temperature and Precipitation Anomalies.
Portions of the Midwest stretching from western Missouri to northeastern Michigan were quite wet in September. The Kansas City area received 5-6 inches of rain, southern Wisconsin and northern Illinois received 5-8 inches, and northeastern Michigan had 5-7 inches (Figure 1). The regional average precipitation, however, was only the 44th wettest September in 107 years, as the northwestern and southeastern portions of the region were quite below normal in precipitation (Figure 2). Some portions of northern Minnesota and eastern Kentucky received less than 50% of normal precipitation for the month (Figure 3). The Midwest was generally cooler than normal this September, ranking 20th coldest in the 107 year historical record. Most of the region was 1-3°F below normal, except for the northwestern half of Minnesota, which was 1-3°F above normal (Figure 4). Michigan had its 18th wettest September, while Ohio had its 13th coldest. At the end of the month, there was some dryness in areas of the western Midwest, but only northeastern Ohio is still in a moderate drought state, and abnormal dryness is present in southeastern Missouri (Figure 5, National Drought Mitigation Center).
Corn progress was ahead of normal in the southern and eastern Midwest, especially in Kentucky, Illinois, and Indiana, where mature corn percentages were 32%, 12%, and 10% above the five year average, respectively. Corn given a quality rating of good/excellent actually declined 2% to 53% in the 18 major corn producing states. This reflected large negative changes in the Dakotas, and smaller negative changes in Indiana and Michigan. The major corn producing states changed 1% or less in g/ex corn. Soybean progress was a bit ahead of normal in the leaf dropping category in the eastern Midwest, by 2-5%. Soybeans were still a bit behind in Wisconsin and Iowa, by 1-2%. The overall quality rating for good/excellent soybeans in the major producer states did not changed since last week, remaining at a fairly low 52% g/ex. Some significant improvement occurred in Michigan and Minnesota, although adding 5% to each still left them at 31% and 45% g/ex, respectively. Nebraska recorded the largest drop in soybean quality, falling 4% to 44% g/ex. The corn this week was past the season when further precipitation would be helpful, but some of the late planted soybeans in the northern Midwest could have still benefitted from some additional moisture.
Corn progress to the mature stage was 16% or more ahead of the 1996-2000 average in Illinois, Indiana, and Kentucky by September 9. In Iowa, though, progress to maturity was 10% behind the recent average, Wisconsin was 11% behind, and Michigan and Minnesota were 6% behind, leaving some vulnerability to an early freeze. The quality ratings rose for the 18 U.S. major producing states, with good/excellent rated corn up 1% to 54%. Quality ratings stayed within 2% of last week in most of the states in the Corn Belt, but those ratings are not very good in a number of states, especially Michigan (25% g/ex) and Minnesota (31% g/ex). Soybean progress was closer to normal than it had been in the last month, with Illinois, Indiana, Kentucky, and Ohio in the eastern Midwest progressing to the leaf dropping stage faster than the 1996-2000 average, while Iowa, Michigan, Minnesota, Missouri, Wisconsin, and Nebraska were behind average pace. The quality of soybeans in the 18 largest producing states increased by 1% to 53% in the good/excellent categories. Illinois and Indiana quality increased 4% in g/ex categories, and Kentucky increased 6%. Otherwise, the rest of the states did not change by more than 2% in quality.
Corn progress to the mature stage remained well ahead of the 1996-2000 average in Illinois (+22%), Indiana (+10%), and Kentucky (+22%). However, Iowa (-16%), Minnesota (-22%), Wisconsin (-13%), and Michigan (-7%) remained well behind the normal pace. The quality ratings improved for the 18 U.S. major corn producing states, increasing 2% to 56% in the good / excellent categories. Only Michigan had a strongly negative week, with g/ex quality falling 6% to an anemic 19%. Soybean progress to the leaf dropping stage remained well ahead of the 1996-2000 average in Illinois (+15%), Indiana (+4%), Kentucky (+10%), Michigan (+11%), and Ohio (+19%). However, Iowa (-24%), Minnesota (-14%), Missouri (-15%), and Wisconsin (-19%) remained well behind the normal pace. The quality ratings improved for the 18 U.S. major soybean producing states, increasing 2% to 55% in the good / excellent categories. Importantly, Iowa showed a strong improvement of 5%, to 56%, while Michigan declined 4% to a poor 25% g/ex. The northern portions of Minnesota experienced a deep freeze, and the northern Midwest states remained vulnerable to an early freeze.
Corn harvest has reached advanced stages in the southern Midwest, with Kansas (41%), Missouri (36%) and Kentucky (50%) well on their way to completion. The northern tier of the Midwest, however, has barely started harvesting corn, and is considerably behind normal in corn reaching the mature stage. Iowa (-20%), Minnesota (-29%), and Wisconsin (-23%) are especially far behind the 1996-2000 average pace to maturation. The quality of the corn did not change for the 18 main corn producing states in aggregate, but Michigan did improve in the good/excellent ratings by 6% to 25%, and Ohio quality rose 3% to 57% g/ex. Soybean harvest has just begun in isolated areas of the Midwest, with the most progress reported in Illinois (11%). A number of states are behind normal schedule for harvest. More importantly, key soybean producing states are well behind the 1996-2000 average for reaching the leaf dropping stage. Iowa (-34%), Minnesota (-6%), and Nebraska (-10%) are large producers at risk for freeze damage prior to full maturation; Iowa and Minnesota experienced freezing minimum temperatures at the end of this period, and may experience more next week. The percentage of soybeans rated good/excellent in the 18 major bean producing states dropped 2% from last week, to 53%.
Severe weather hit the region on several days during the period. On September 6, tornadoes swept through Iowa and Wisconsin (Figure 27, SPC). The storms in Iowa were unfortunate in their timing, disrupting a Senior PGA golf tournament when a tornado caused damage at the golf course, injuring one spectator who was in a tent. An 8-car garage was also destroyed. The strong storms (Figure 28, NWS) also dumped 3-4 inches of rain, causing some localized flash flooding. On the same day, a tornado in Wisconsin blew out the windows of a supper club at Pelican Lake, WI. Windy storms redeveloped on the 7th, leading to 247 separate severe wind reports from Michigan to Oklahoma (Figure 29, SPC). The MetLife blimp Snoopy II broke from its moorings at the Downtown Kansas City Airport and was swept along for 75 miles to the east until it deflated and snagged on a parked truck. Considerable damage occurred in eastern Missouri, with 20,000 customers left without power in the St. Louis area. Nine people were injured when high winds turned over eight 30-40 foot motor homes at an RV park near and East St. Louis casino. The home of U.S. Senator Jean Carnahan near Rolla, MO, was struck by lightning and severely damaged by fire. September 8 was fairly quiet in the Midwest, but the 9th brought one more blast of severe weather to the central and eastern portions of the region (Figure 30, SPC). The most noteworthy event was a tornado in Delta township, near Lansing, MI. The storm injured one person as it damaged several houses and business, but also took out a cooling tower at the Erickson Power Plant, causing damage at that one site in excess of $4 M. The storm was rated as an F1 at its most severe, and had a path 9 miles long and up to 900 feet wide. This was quite a busy week for so late in the severe weather season.
Severe weather was quite limited during the September 12-18 period. One substantial event did occur, though, when heavy rains caused flash flooding in the area of Kansas City, MO, on September 16-17. The Kansas City International Airport received 4.38 inches of rain on the 16th, and some nearby areas received even more according to radar estimates (Figure 31, NWS). The rain caused a great deal of street flooding, and some river flooding. The Little Platte River crested at 8 feet above flood level in Smithville, flooding some state highways and streets in the area. Fortunately, no one was injured, but a few houses were affected by flood waters.
Rains accompanying the first low pressure system resulted in flash flooding in the Chicago area, where more than 4 inches of rain fell in Aurora and other western and northwestern suburbs. A new daily precipitation record was set at O'Hare airport two days in a row, 1.72 inches on the 19th and 1.33 inches on the 20th. Some flooding took place along local rivers, but damage was fairly limited, and the major expressways were not flooded as happened twice in August. About 3,500 utility customers lost power in the Chicago suburbs. Following the widespread rains, dense fog formed as cool air entered Minnesota and the surrounding states on the 20th. Due to zero visibilities, Minneapolis/St. Paul International Airport was closed, and school was delayed throughout the region. The frontal passage on the 23rd also brought isolated heavy rain and several dozen severe weather reports, including some in central Indiana. A report of 2.3 inches of rain falling in 20 minutes was received south of Indianapolis in Morgantown, which would be a greater than 100-year return interval event.