June 2010
Midwest Overview - June 2010
Heavy Rains for Much of the Midwest
June was a wet month for much of the region. Precipitation totaled two or more inches above normal in part of each Midwest state with southern Iowa more than eight inches above normal (Figure 1). Iowa's statewide total exceeded ten inches (10.34 inches based on preliminary data) and was challenging not only the June record (10.33 inches in 1947) but also approaching the all-time record (10.50 inches in July 1993). Illinois had its second wettest June on record (7.8 inches), only topped by June 1902.
Daily precipitation records were recorded throughout the month with nearly 1000 records set. Seven days recorded 50 or more records and just five days failed to record 10 or more. Eight states (all but Kentucky) had at least one Cooperative Station report over 10 inches, with 157 stations reaching double digits as large precipitation totals spread across the Midwest (Figure 2).
June rains in the Upper Midwest alleviated most of the short-term drought concerns. However, multi-year precipitation deficits in the Upper Midwest have not yet been made up and lake levels remain low (Figure 3). The southern part of the Midwest and small parts of Minnesota and Ohio received slightly below normal precipitation in June (Figure 4). Southeast Missouri was particularly dry, receiving just a small fraction of its normal June rainfall.
Warm in the Southern Half of Midwest
The southern half of the region was above normal in June. Temperatures were near normal (-2° to 2°F) in the northern half of the Midwest and warmed further to the south with departures of 5°F or more in southeast Missouri and western Kentucky (Figure 5). Minimum temperatures were slightly warmer ranging from 0°F to 7°F above normal (Figure 6). Daily temperature records were dominated by record high minimum temperatures which accounted for more than three quarters of the June records. Missouri reported its warmest June since 1953 with temperatures running 4° to 6°F above normal across the state.
Deadly Tornadoes
June was a busy month for severe weather in the Midwest with more than 2000 severe weather reports (Figure 7). Dozens of tornadoes caused extensive damage. Five of the tornadoes were responsible for 10 deaths (Figure 8). On June 5th in Millbury, Ohio (Wood County), six people died as an EF4 twister ripped through town after dark. Minnesota and eastern North Dakota took the brunt of a tornado outbreak on the afternoon of June 17th. Twenty tornadoes, including three EF4 storms, were spread across the states. Three Minnesota tornadoes were each blamed for a death, one each near Mentor (Otter Tail County), Almora (Polk County), and Armstrong (Freeborn County). On June 27th, a weaker EF1 tornado struck a campground in St. Clair County, Michigan causing the tenth tornado death in June.
Flooding
The large rains throughout the month caused flash flooding in many locations as water overwhelmed sewer systems, ponded in low lying areas, and swelled creeks and streams. Rivers in the central and west central parts of the Midwest climbed out of their banks as the extensive runoff accumulated (Figure 9). Flooding in Iowa led the governor to place 29 counties under a state disaster proclamation (numerous Iowa counties).
Farm Conditions Highly Variable
Farms conditions vary greatly across the Midwest. In southeast Missouri, the lack of June rain is threatening unirrigated fields. The Upper Midwest has quickly gone from drought concerns to wet, preventing field work as wet soils and standing water resulted from heavy rains late in the month. In the central Midwest there was widespread heavy rain but the effects on fields varies by location. In well drained fields the crops are making use of the warmth and abundant water to rapidly grow, while in low lying fields all the water has drowned crops, led to uneven growth, and prevented badly needed herbicide applications.
-MST-