Midwest Weekly Highlights - March 18-24, 2012

---

Record Warmth Continues

Daily temperature records continued to fall in the third week of March. Temperature readings in the 80s extended into the northern extents of the Midwest, exceeding normal by 40°F in a few cases. Records (1650+ maximum temperature records and 2150+ minimum temperature records) fell by the hundreds each day during the week. Each day in the week saw over 200 records fall, peaking on the 20th when over 800 daily records fell on a single day (Figure 1). In addition to the thousands of daily records, 600+ of these records were also records for any date in March. The daily and monthly records were spread across all nine Midwest states. For the week, temperatures averaged 9°F to 33°F above normal (Figure 2). Southwest Missouri was about 10°F above normal with departures ranging to more than 30°F above normal in parts of Wisconsin and Michigan. Even as the heat moderated slightly late in the week, temperatures remained well above normal (Figure 3). With seven days remaining in March, the region as a whole, and all nine states in it, were on pace to set new records for the warmest March (statewide records back to 1895).
 

Heavy Rains In Western States

A low pressure system developed in the southern Great Plains (Figure 4) and pumped moisture from the Gulf of Mexico into the Midwest over three days, the 20th to 22nd. The heaviest rains fell in southwestern Missouri with totals ranging from 2" to 6" (Figure 5), three to six times normal for the week (Figure 6). Flood and flash flood watches were issued on the 20th as the storm got under way in Missouri (Figure 7). Northern Minnesota picked up between 1" and 1.50", three to five times normal. The rains in northern Minnesota should put a small dent in the drought (Figure 8) when next week's report is released. Dozens of daily precipitation records were set from Missouri to Minnesota on the 20th to 22nd and dozens more later in the week as the system moved eastward.
 

Severe Weather

Early in the week, there were numerous severe weather reports, mostly wind damage reports in the western half of the region and hail reports in the eastern half (Figure 9). On the 23rd severe weather stretched from the Mississippi River east to Ohio (Figure 10). The severe reports on the 23rd included wind, hail, and tornadoes including an EF2 rated tornado near Mt. Vernon, Illinois (Jefferson County) that was responsible for one death and two injuries.
 

-MST-