Midwest Weekly Highlights - September 1-7, 2007

A Quiet Start....

September opened up on a dramatically different tone than August ended. A change in the weather pattern brought warmer and drier conditions across the Midwest. A great portion of the Midwest had clear skies with no clouds in sight to start. September started out with high pressure dominating the surface while an upper level ridge kept any disturbances away from the area. Temperatures were well above normal across the northern Midwest (Figure 1). Wisconsin has been taking the brunt of the worst for this recent season. Last month torrential rains broke many records across the state and flood waters are just now starting to recede (Figure 2). Temperatures across the Midwest this week averaged from 2°F below normal to well over 9°F above normal. Wisconsin typically sees temperature averages begin to make a dramatic shift from the lower 70's to middle to lower 60's through September. Average temperatures across the majoity of Wisconsin were well over the normal values. Minnesota was the other warm location for the Midwest with temperatures ranging from 8°F above normal down to 1-2°F above normal. Missouri was the coolest location as cloudy skies and rains kept the temperatures down.
 

The Drought Continues

Drought conditions did not improve across the area as mother nature's oven was turned on high over the Midwest. Heavy rains fell across the western Midwest and into the Upper Peninsula of Michigan. A few bands of extremely heavy rain fell in Marquette, MI dropping 4.29" on the September 4th alone. That not only breaks the record for September 4th, but is also an all time record 24 hour precipitation for Marquette. The previous record occurred on October 24th, 1959 when 4.06" of rain fell. Houghton, MI also saw the same two records set. 3.58" of rain also fell with the storms that moved across the U.P. of Michigan. The previous all time record occurred on August 3rd, 1955 with a total 3.23" of rain falling in 24 hours. These rains should help deflate some of the drought conditions across the U.P. of Michigan in the coming week. Unfortunately most of the rain that fell occurred outside of the the already drought stricken areas. There was minimal change to the existing drought classification across northern Minnesota, Wisconsin and lower Michigan (Figure 3). The extremely dry weather across the Ohio Valley allowed the drought conditions to creep slightly north into areas of southern Illinois, Indiana and Ohio. To date over 60% of the Midwest is classified as being in some form of drought, while 30% of the Midwest is classified as D2 (severe drought) or worse. Most of the Ohio Valley and east lacked any real precipitation (Figure 4). Some of the hardest hit areas with drought failed to see even a trace of rain fall over the last week. There may be some relief in the works soon. The Hydrologic Prediction Center is forecasting good heavy rains to fall over the area in the coming week (Figure 5).

Portions of agriculture benefited from the warmer and dryer conditions by allowing the crops to mature quicker. It also had an adverse effect on areas that have had minimal rains this season by putting the crops under a lot of stress.
 

Daily Records September 1-7

Daily records for the first week of September can be viewed in Table 1.

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