Midwest Weekly Highlights - July 11-17, 2012
Widespread Below Normal Precipitation
A majority of the Midwest is either abnormally dry or experiencing some level of drought. Unfortunately, this week did not bring much precipitation relief for a majority of the region. Kentucky was the only state to receive normal to above normal precipitation, with at least 1" of precipitation, and in some places up to 3", falling across much of the state during the week (Figure 1). The precipitation in Kentucky produced rainfall totals that were 200%-300% above normal (Figure 2), bringing some relief to parts of the state that have been experiencing abnormally dry conditions for about a month now. Unfortunately, the most drought stricken areas of the state are in western Kentucky, which received less precipitation relief during the week.
The rest of the Midwest received very little precipitation, ranging from 0" to 1" of precipitation. Overall, these totals were below average for the week, with much of the region receiving less than 50% of normal precipitation. There were some daily precipitation records set during the week, mainly occurring from July 13th to July 15th.
Above Average Temperatures Continue
Temperatures continued to run above normal for much of the Midwest during the week, with the highest departures of 7°F to 9°F above normal occurring in southern Wisconsin, northern Minnesota, and Upper Michigan (Figure 3). Southern Kentucky and the Missouri Boothell experienced near-normal average temperatures throughout the week.
Similar to much of the summer, temperature departures were more above normal for maximum temperatures than minimum temperatures during the past week. Maximum temperatures were 9°F to 11°F above normal in southern Wisconsin, southern Michigan, and northern Indiana (Figure 4). Much of the region experienced maximum temperatures that were at least 5°F to 6°F above normal. However, southern Kentucky had maximum temperatures that were 1°F to 3°F below normal. Minimum temperatures, on the other hand, were generally only above normal by 1°F to 3°F for much of the region (Figure 5). The highest departures of +8°F to +11°F from minimum temperatures were in northern Minnesota and Upper Michigan.
While the temperatures were above normal this week, there was some relief from the heat compared to the beginning of the month. Over the past week, record highs were set, but they aren't as numerous as the records set at the beginning of the month (Figure 6). Despite the lower number of record highs, there were still several daily temperature records set throughout the week, with even a few record lows set in Kentucky, Wisconsin, and Ohio. A few monthly records and all-time records were also set during the week.
Expanding Drought and its Impacts
Once again, the latest release of the US Drought Monitor shows an expansion of drought conditions in the Midwest (Figure 7). Currently, almost 73% of the region is either in D1 (moderate), D2 (severe), D3 (extreme), or D4 (exceptional) drought. The area experiencing exceptional drought expanded by 0.5% this week, now impacting portions or the entire area of 13 counties in Kentucky, 6 counties in Illinois, and 2 counties in Indiana.
The drought has had a major impact on agriculture in the Midwest. According to the National Drought Mitigation Center, this drought couldn't have come at a worse time for the development of crops in the region. Unfortunately, approximately 78% of the corn grown in the United States is within an area experiencing drought (Figure 8). As a result of the drought, corn yield potential is drastically decreased and the quality of corn has steadily deteriorated over the last month (Figure 9). In the region of the Midwest experiencing extreme and exceptional drought, the impacts of drought on agriculture are quite noticeable (Figure 10) (Figure 11) (Figure 12).
Unfortunately, the US Seasonal Drought Outlook does not expect conditions to improve from July 19th to October 31st. Existing drought conditions are expected to persist or intensify and drought development is likely in other parts of the Midwest (Figure 13).