March 2006
Midwest Overview - March, 2006
The month of March was very active, with several instances of severe weather followed by longer lasting cool-downs. At the end of the month, the average daily temperature departures across the region for March were generally near normal, ranging from 1-3°F above normal across Minnesota, northern Wisconsin, and northern Michigan, to near normal across Illinois, Indiana, and Missouri. The coolest part of the Midwest this month was in Iowa, Ohio, and Kentucky, where temperatures were 1-3°F below normal (Figure 1).
Precipitation for the month was generally at or above average for a good portion of the Midwest (Figure 2). The heaviest precipitation fell across western and northern Illinois into southern lower Michigan, where precipitation totals were 150 to 200% of normal. Much of Minnesota and central Iowa saw precipitation deficits, with generally 25 to 50% of normal across Minnesota and 50-75% of normal in Iowa. Due to generally near average temperatures this month, precipitation was mainly in the form of rain, although a few systems brought some snowfall, and some of it was heavy across the central Midwest. Snowfall for the month of March was generally confined to the northern portions of the Midwest (Figure 3).
Frequent Severe Weather Episodes Mark an Active March
Several rounds of severe thunderstorms hammered the Midwest this month, the most notable occurring on March 12, 2006 (Figure 4). On this day, numerous tornadoes tracked across Missouri and into Illinois, destroying homes, blowing semi-trailers off of highways, and injuring several persons. The storms even resulted in a few deaths in Missouri when a couple tried to run away from an approaching tornado only to have the tornado throw their vehicle into a roadside propane tank, killing both just 50 yards from their home. The storms brought heavy, flooding rains, rising river levels across southern Illinois and Indiana. The drought region (Figure 5) saw some much needed precipitation during March, but streamflow analysis indicated that short-term heavy rains only temporarily eased drought concerns, before returning to previous low levels, indicative of the persistence of long-term dryness. Once the first round of severe weather passed, the Midwest turned much cooler than normal, and snowier than normal. This regime resulted in one massive snowstorm on March 21, dropping significant snows across southern Iowa, northern Missouri, and central portions of Illinois and Indiana (Figure 6). The snow did not stay long, however, as near normal temperatures helped to melt the snow cover. By the end of the month, a return to southwest flow aloft signaled a pattern change and resulted in more frequent opportunities for stormy weather. This was particularly true on March 30-31, when a storm system rolled out of the Plains states and into the Midwest. Over 500 reports of severe weather were documented during this two-day period.
[For more details on weather and climate events during March 2006, please click on the individual weekly report links on the upper right.]
Kruk