Winter Storm in Iowa, February 8 to 9, 2001

As the storm system mentioned above continued to evolve, cold air was drawn into the system. In part, the cold air moved in, brought in on northerly winds behind the surface low. A secondary factor was the convection. As thunderstorms continued to move northeast into Iowa, the freezing rain that was falling began to transition over to frozen precipitation. Initially freezing rain became mixed with and changed over to ice pellets as the cold air became deeper. The transition was slow with an extended period of ice pellets in many areas. It was not uncommon to receive reports of an inch or more of accumulation of the ice pellets. The transition eventually worked its way southeast across the state and by sunrise on the 9th all of the Des Moines CWA had changed over to snow. Snow fell heavy for a period of time with snow falling at nearly an inch per hour shortly after the change to snow occurred. During the mid day hours of the 9th, the upper level low pressure system moved across the state. This produced another band of heavy snow with snowfall rates of one to two inches per hour. The snow did not last a long time from this part of the storm however. By the time all was said and done, four to six inches of snow was common from southwest, into central, and into northeast Iowa. Some of the heaviest snow occurred over the southwest and south central counties of the state where more thunderstorms were reported. The town of Lenox in Taylor County reported 9.5 inches of snow from the storm. There were numerous reports of 5 to 6 inch snowfall amounts occurring during the morning and early afternoon of the 9th in the central counties from Des Moines north through Ames and Marshalltown. As the surface low began to move away from Iowa, winds increased from the northwest. Gusty northwest winds of 20 to 35 MPH caused considerable blowing and drifting snow with numerous reports of visibility near zero during the afternoon hours. Travel was not recommended over all but the far northwest part of Iowa. Interstate 80 was closed from Des Moines west to Omaha. Interstate 35 was closed from Des Moines north to the Minnesota border. The National Guard was called out during the afternoon of the 9th to help rescue stranded motorists. State and Federal offices were closed across the state on the 9th as well as most businesses. Nearly all activities were were postponed or canceled.