Midwest Weekly Highlights - June 10-16, 2009
Wet Pattern Returns to Central and Southern Midwest
Heavy rain returned to much of Missouri and Illinois this week as farmers struggled to find a weather window to complete corn and soybean planting. The rain was focused along a frontal system that oscillated north to south and back north again during the week. Rainfall was two to more than four times normal across Missouri, the southern half of Illinois, the southern third of Indiana, Kentucky, and southwestern Ohio. In contrast, it continued to be dry across the northern Midwest with little or no rain this week in many areas (Figure 1). The largest amounts of rain this week fell in central Missouri (4.00 to 6.00 inches), southern Kentucky (2.00 to 4.00 inches), and northeastern Illinois (2.00 to 4.00 inches) (Figure 2). The June 16 U.S. Drought Monitor continues to depict dry conditions from southeastern Minnesota through northwestern Wisconsin to the western Michigan U.P. (Figure 3). Spring planting of corn and soybeans, normally completed in late May to early June for corn and in mid to late June for soybeans, was still running behind schedule. As of June 14 corn planting was complete except in Missouri, Illinois, and Indiana, where it was at 97 percent complete. Soybean planting was one to two weeks behind schedule in Missouri and Illinois, and about a week behind in Indiana and Kentucky.
The range of temperatures across the Midwest reflected the mean position of the frontal zone across the region. Temperatures were near normal across southern Missouri, southern Illinois, southern Indiana, southern Ohio, and all of Kentucky. Temperatures across the remainder of the region ranged from 1°F below normal in the central Midwest to as much as 8°F below normal in southwestern Minnesota and northwestern Iowa (Figure 4). Record low maximum temperatures were set at a number of locations across the northern half of the region from June 10-14. Growing degree days (GDD) since May 1 were near normal in Kentucky and southern Ohio. North of the Ohio River, GDD ranged from 60 GDD below normal south to 200 GDD in northwestern Minnesota (Figure 5).
The morning of June 10 found a stationary front bisecting the Midwest with a wave of low pressure located in central Kansas (Figure 6). Thunderstorms fired along and north of the front during the day, producing three tornadoes in Missouri and one in Illinois. All of these produced only minor damage. The storm associated with the tornado in Fayette County, IL produced golf ball size hail which caused some property damage. The heaviest rain from this round of storms fell in much of Indiana and Kentucky, with one to two-inch amounts common. In Indiana, almost the entire state reported an inch or more of rain on June 11, while some counties reported totals of close to 1.50 inches. Southern Indiana and Kentucky experienced severe weather again on June 11 as the front remained stalled over the region. Thunderstorms and heavy rain in southeastern Kentucky resulted in damaging winds and flash flooding. Numerous trees were downed and flood waters closed roads in the region stretching from McCreary to Pike County. In Pike County, a local fire rescue team was called to rescue a person trapped in a vehicle, and flood waters damaged homes. Rainfall amounts of 1.5 to 3 inches were common throughout the region. This was the second time that many of these areas were hit by flooding in just over one month.
Later in the evening, a severe thunderstorm produced two tornadoes and intense lightning in south central Kentucky. An EF1 tornado with wind speeds estimated from 75 to 105 mph touched down near the Edmonson/Warren county line and moved to the east-southeast into Barren County. Damage was limited to trees, barns, and two homes. No injuries or fatalities were reported. The second tornado, also an EF1 touched down in Metcalfe County. Though its path was short, damage was reported to a home, farm buildings, crops, and trees. Minor damage was reported to crops and trees. However, golf ball to baseball size hail was reported in Daviess County. An EF0 tornado also touched down briefly in Henderson and Daviess counties, and a brief tornado touched down in Pike County, IN.
Much of the Midwest enjoyed a break from wet weather as the front pushed south of the Ohio River by dawn on June 12. The front began to return north late on June 12 and produced scattered showers and thunderstorms through June 14, with a few severe storms on June 14 in northern Kentucky and southern Ohio.
The weather map on the morning of June 15 was very much like that on June 10 - a front was draped across the the central Midwest with low pressure developing on the front in Kansas (Figure 7). Overnight, training thunderstorms in northwestern Missouri. Two to four inches of rain fell in a narrow band across Andrew and DeKalb counties. The complex of thunderstorms continued eastward during the day, bringing heavy rain to eastern Missouri and southern Illinois before it gradually died out.
Missouri Hammered Again
Another upper level wave of low pressure moved out of Kansas and into western Missouri during the late afternoon and evening. A line of severe thunderstorms erupted ahead of the wave, crossing the Kansas-Missouri line around 11:00 p.m. CDT on June 15. (Figure 8) Winds gusting from 60 to 70 mph accompanied the storms resulting in many downed trees and power lines. An estimated gust to 90 mph was reported near Drexel, MO (Bates County), knocking a house of its foundation. The storms continued eastward overnight, diminishing in severity but continuing to produce heavy rain. This wave of storms produced two to four inches of rain from St, Louis County, MO into the Metro East area in Illinois. By 2:00 a.m. on June 16 the leading edge of the storms was pushing into eastern Missouri (Figure 9). The heavy rain from the storms produced flash flooding throughout the St. Louis metro area. In Brentwood, MO (St. Louis County), three to four feet of water covered baseball fields in a local park. The River Des Peres was out of its banks in University City, flooding back yards and threatening homes. A flash flood watch covered much af Missouri and southwestern Illinois, and many counties in Missouri were under flash flood warnings (Figure 10).
As this first wave of storms moved into the southern half of Illinois, another line of storms was developing over southeastern Missouri (Figure 11). This line intensified during the morning and marched steadily eastward during the afternoon (Figure 12). Severe Thunderstorm Watches were issued ahead of the line for southern Illinois, Kentucky, and Tennessee. Severe Thunderstorm Warnings were issued ahead of the line during the afternoon. There were numerous reports of wind damage clustered along the entire length of the Kentucky-Tennessee border. There was a possible tornado touchdown in Laurel County, KY. One injury due to high winds was reported in Leslie County, KY from a falling tree.
Flooding Rain in Northeast Illinois
While storms rolled across Kentucky and June 16, showers and thunderstorms developed in northeastern Illinois in association with a mid-level low pressure disturbance. Training thunderstorms dumped more than 4.00 inches of rain in western Will County beginning in the late afternoon, and 1.00 to more than 1.50 inch amounts were common through the Chicago metropolitan area.