March 7-13, 2001

The week of March 7 to 13 was very active in the Midwest, especially in the Great Lakes region, where 2 clipper systems and a major low pressure center moved through in just seven days. The water content of the precipitation in the region was less than an inch in the wettest areas of Iowa and eastern Ohio (Figure 7). Precipitation was quite light with the clippers, and the majority of both the liquid water equivalent and snowfall occurred with the major winter storm that traversed the area March 10-12. The low pressure center moved from western Iowa to northern Michigan, with a long frontal boundary reaching southward. Most of the available moisture and jet stream energy stayed south of the Midwest, and the South experienced heavy rain and severe weather. The snowfall in Minnesota and Wisconsin was especially heavy, with many places getting 6-12 inches (Figure 8). Notable concerns began to surface regarding the potential for flooding in these states if the ample snow pack melted rapidly, especially in the valley of the Red River in far northwestern Minnesota. Even in central Minnesota, 4-6 inches of snow water equivalent lay on the ground, ready to flood the Upper Mississippi River during an abrupt spring melt. However, in most of the southern half of the Midwest, it was quite dry this week compared to normal (Figure 9). In addition, temperatures were 4-7°F cooler than normal in the snowy areas of western Iowa and southern Minnesota (Figure 10), so snow pack melting remained slow at that time.