Midwest Overview - March 15-21, 2003

The week started out very mild.  Maximum temperatures on the 16th were in the 60s and 70s throughout the entire region.  Numerous record maximum temperatures and some record high minimum temperatures were set in Minnesota, Wisconsin, and Michigan, Iowa and Missouri on the16th.  Additional records were set in Illinois and Ohio on March 17th.   The spring-like weather continued most of the week, and as a result temperatures averaged 8 to 12 degrees above normal across the Midwest (Figure 1).  A strong low pressure system spread rain and thunderstorms across lower Midwest on the 19th, while to the north some freezing rain glazed parts of northern Minnesota and Wisconsin, causing some minor travel problems.  By the 20th this storm system dominated the eastern half of the country (Figure 2). While most of the Midwest received some precipitation, amounts were heaviest in the southern half of the region.  Precipitation for the week amounted to 1.00 to 1.50 inches from the southern half of Missouri into Kentucky (Figure 3).  While most of the northern half of the Midwest did receive precipitation, amounts were generally less than 0.50 inch.  On March 16th La Crosse, WI experienced its wettest day since October 4, 2002 when it received 0.44 inches of precipitation. On October 4,2002 1.19 inches of rain fell, and since October 1 La Crosse has experienced only six days with precipitation greater than one quarter of an inch.  Precipitation is less than 75 percent of normal for the period in a SW to NE band across the central Midwest (Figure 4).  The largest precipitation deficits since October 1 exceed six inches in north central Illinois (Figure 5).