Interstate 80 Temperature Split

It just happened to work out that Interstate 80 was the division between above normal and below normal average temperatures this week (Figure 1). The week began with a stalled out cold front situated over the I-80 corridor, which eventually was replaced by a five-day stint of high-pressure systems over much of the region. Another cold front moved through Minnesota and stalled near the I-80 corridor on July 7th. To the south, temperatures ranged from 1 to over 6°F below normal. North of I-80, average temperatures ranged from 1 to over 8°F above normal. Barry County, located in southwest Missouri (WASHBURN 5 W), recorded an average temperature of 71.6°F, which was 6.4°F below normal. Beltrami County, located in northern Minnesota (RED LAKE INDIAN AGCY), punched in an average temperature of 75.1°F, which was 8.2°F above normal for the week. Average maximum temperatures ranged from 85-90°F through much of Minnesota and Iowa (Figure 2), which attributed to many of these locations being 5 to 10°F above normal for the week (Figure 3).

Variable Precipitation Amounts

A couple of dissipating rain events and a stretch of high-pressure systems attributed to widely variable precipitation amounts across the region (Figure 4). East-central Iowa, northern Minnesota, northern Illinois, and southern Wisconsin missed out on rain opportunities. As of July 7, Corning, located in southwestern Iowa, had a streak of 11 days without precipitation. Southern Minnesota through Michigan received 0.5 to 3” of rain, which was up to 2” above normal (Figure 5). Missouri through the Ohio River Valley had isolated rain events with areas receiving as little as 0.01” to as much as 5.44” of rainfall.

Few Storm Reports

Compared to last week, storm reports were quiet. There were 74 wind storm reports across the region and one hail report. The most notable events occurred on July 6-7 (Figure 6) and (Figure 7), where 69 miles per hour wind speeds were measured at Macomb and Calhoun, Michigan. Many of the reports indicated downed trees, powerlines, and blown-over semi-trailers.

Drought Monitor Update

The July 6th U.S. Drought Monitor showed some improvement with a 2.81% decrease in the percent of land in D0-D4 compared to the previous week (Figure 8). Much of D0 (Abnormally Dry) conditions improved to None in southern Michigan, central Indiana, northern Illinois, and eastern Iowa. Central Iowa through northern Minnesota saw an expansion of D2 (Severe Drought) conditions, which was attributed to the lack of rainfall this week.