Winter Storm in Iowa, March 8, 1999

A major winter storm swept into the central U.S. during the early morning hours of the 8th. For a March storm, this storm could have certainly been much worse however. It is interesting to note that in 1998 a snowstorm producing 10 to 20 inches of snow occurred on this same date. Arctic high pressure was poised to the northeast of Iowa with surface pressures in the center of the high in excess of 1050 mb over northeast Canada. This high fed cold air into the central U.S. Meanwhile, low pressure moved through the Rockies on the 7th and moved out onto the Plains during the night of the 7th. Initially, the surface low was located over the northern Rockies. At the same time the low was moving southeast, a strong upper level low moved east across the southern Rockies. The two systems phased on the 8th with the main surface low forming over Kansas. From there it continued to move east across southern Missouri, and then eventually toward southern Kentucky. Moisture from the Gulf of Mexico was plentiful and fed into the storm. A very large area of snow broke out northeast of the low during the predawn hours of the 8th. The first wave of snow came as the initial warm air advection took place. Visibility was reduced to under one quarter mile at many areas as a quick one to three inches of snow fall. The second round of snow moved in before dawn on the 8th and produced heavy snow of one to two inches per hour and visibility reductions once again under one quarter mile. During the day on the 8th, the snow area became broad with moderate to occasionally heavy snow reported. Some freezing rain and ice pellets were reported over south central into southeast Iowa. The icing was not severe as the amount of freezing rain was minimal and lasted only about 3 hours. Surface winds increased during the day with 20 to 30 MPH winds reported over the south half of the state, and 25 to 40 MPH winds over the north. These winds caused considerable drifting snow and some whiteout conditions. Reports indicated that snow drifted into drifts in excess of 6 feet in places. The main feature with this storm was the heavy snowfall as conditional symmetric instability resulted in bands of convective snowfall. A large part of Iowa received in excess of 8 inches of snow with most areas south of U.S. Highway 20 reporting in excess of 8 inches. A narrow band of 8 to 10 inch snowfall occurred over north central Iowa. In this band, heavier totals included 11 inches at Mason City and 10.5 inches at Britt. A large area of 10 inch or greater snowfall occurred over west central into Central Iowa, generally north of U.S. Highway 34 and from Interstate 35 west. Two areas of very heavy snow were reported. In the Carroll area, the greatest snow total in the state was reported with 16 inches of new snow. Sixteen inches of snow also fell in the town of Breda. Audubon was close behind with 14 inches. An area of a foot or more covered a large part of Carroll and Audubon Counties as well as the northwest half of Guthrie County. The second area of very heavy snow was over central Iowa. This area covered southwest Polk County, southern Dallas County, and most of Madison and Warren Counties. Snowfall in these counties was in the 12 to 14 inch range. The heaviest official totals came from Des Moines with 13.1 inches and Winterset with 13.0 inches. Travel was hampered with this storm, though most roads did remain open throughout the storm. Numerous accidents were reported around the state as roads became slick due to the very wet nature of the snow. The weight of the snow also presented problems in that it caused some minor damage and spotty power outages as some branches were broken. Many businesses and most schools closed for the day. A few school districts remained closed the 9th as well due to drifted roads.