Midwest Overview - March 2012
Record Breaking Warmth
It was the warmest March on record for the region as a whole and for each of the nine states. The statewide records were broken by two or more degrees in most cases as March's weather was dominated by a strong warm advection over the eastern part of the country that lasted nearly two weeks (Figure 1). Over 6400 daily temperature records were set in March with 200 or more each day from the 14th to the 24th, peaking with over 800 records on the 20th alone (Figure 2). More than 650 of the daily records also were records for any day in March. Numerous cities across the Midwest also set records for the month.
Temperatures were well above normal across the Midwest, ranging from just over 10°F above normal in southwest Missouri and southeast Kentucky to more than 16°F above normal in northwest Iowa, southeast Minnesota, and west central Wisconsin
(Figure 3). During the peak of the heat mid-month, temperatures ranged from about 13°F above normal in southwest Missouri to nearly 30°F above normal in parts of Wisconsin and Michigan (Figure 4) as some locations reached temperatures more than 40°F above normal for a particular day.
Mixed Precipitation Depends on Location
Precipitation in March varied from less than 10% of normal in central Illinois and northern Wisconsin to more than three times normal in northwest Minnesota
(Figure 5). Wet conditions were found in northern Minnesota, from southwest and south central Missouri north to southwest Iowa, southern Wisconsin, most of lower Michigan, along the coast of Lake Erie, and scattered areas in the Ohio River valley. The first of two large areas of dry conditions extended from northwest Iowa and southern and central Minnesota, across northern Wisconsin and into upper Michigan. An additional area of dry conditions included most of Illinois, western Indiana, and smaller parts of the neighboring states. Drought status changed little in March with the only change in northern Minnesota where a small area dropped from Moderate Drought status to Abnormally Dry (Figure 6). With the warm and mostly dry conditions, snowfall was below normal for most of the region
(Figure 7). Only northern Michigan, and surprisingly, northern Kentucky, were two or more inches above normal for the month. In contrast, most of the northern half of the Midwest was 2" to 8" below normal.
Eight Deadly Tornadoes on the 2nd, and Another on the 23rd
March started deadly with 39 tornado fatalities on the 2nd in the southeast part of the region. Eight deadly tornadoes, ranging from EF1 to EF4, touched down in southern Indiana, southern Ohio, and eastern Kentucky on that one day. In Kentucky, 22 died in four separate tornadoes. Indiana had two deadly storms leaving 13 dead and Ohio had four deaths in two additional tornadoes. On the 23rd, an EF2 tornado in southern Illinois killed one. Severe thunderstorms touched all nine states in March but most of the activity occurred in the southeast third of the region, especially areas within 100 miles of the Ohio River (Figure 8).