Midwest Weekly Highlights - April 15-21, 2009

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Precipitation Varies Again

A variable rainfall pattern developed again this week. Rainfall amounts ranged from less than half of normal in northern Missouri, Iowa, Minnesota, and western Wisconsin to more than twice normal in eastern Ohio, southeast Michigan, north central Wisconsin, and upper Michigan (Figure 1). Severe drought continued in parts of the upper midwest, but rain brought an end to most of the abnormally dry conditions in southern Ohio (Figure 2).

Heavy wet snow fell in the arrowhead of Minnesota, upper Michigan, and north central Wisconsin on April 19th-20th. More than a foot of new snow was reported at numerous stations. This snow increased the extent of the previously dwindling snow pack (Figure 3).
 

Temperatures Close to Normal

Temperatures started the week warmer than normal and cooled later in the week. On average, most of the region was within 3°F of normal for the week (Figure 4). Slightly above normal temperature in the north transitioned to slightly below normal further south with temperatures reaching 3°F to 5°F below normal in Kentucky, extreme southern Illinois, and southeastern Missouri. The only daily temperature records set this week were several record low maximum temperatures.
 

Storms Slow Their Pace

After several weeks with multiple storms, the pace of storms slowed this week. The week began with high pressure building across the region following a storm system that moved off to the east. A slow moving storm system developed in the Rockies dumping several feet of snow in Colorado and soaking the high plains and Texas as it moved east. Severe weather moved across the southern states, but largely spared the midwest. Dry, warm weather to start the week changed to rainy, cold weather as the storm slowly drifted across the midwest in the latter part of the week.
 

Local Impacts

Cool daytime temperatures, rain, and wet soils limited farm fieldwork in the southern half of the region.

Severe thunderstorms occurred on just one day (April 18th), in one county (McDonald county, MO). Several buildings were blown down in Anderson and hail up to 1.5" in diameter was reported in Noel.

The heavy snow in northern Wisconsin (Oneida County) brought down trees and power lines leaving about 7000 residents without power for two days.

Major flooding along the Red River and moderate flooding along the lower Illinois River were improving by the end of the week (Figure 5). After a month of flooding in Fargo and Moorhead, the removal of sandbags and earthen dikes has begun.
 

MST