March 2015
Midwest Highlights - March 2015
Cooler March
Average temperatures across the Midwestern region during the month of March ranged from 20-25°F along the shores of the Great Lakes, warming to the lower to middle 30s through Minnesota, Michigan, and Wisconsin, across northeast Iowa, and across northern Illinois, Indiana, and Ohio. Average temperatures of 35-40°F extended from northwest to southeast Iowa, across central Illinois, central Indiana, and the southern half of Ohio. Regions south of this line saw average temperatures of 45-50°F with southwest Missouri and southern Kentucky having experienced average temperatures of 50-55°F (Figure 1).
In relation to the average, these temperatures were below normal across the central portion of the region, with Illinois, Michigan, Indiana, Ohio, southeast Missouri, and the northwest half of Kentucky experiencing average temperatures 2-4°F below normal. Minnesota, the northern half of Wisconsin, the western half of Iowa, and northwest Missouri experienced average temperatures 2-4°F above average (Figure 2). The warmer temperatures in the western portions of the region were more influenced by daily observed maximum temperatures (Figure 3), and the colder temperatures over the central portion of the region were more influenced by daily observed minimum temperatures (Figure 4).
Preliminary data shows that new records were established for observed daily lowest minimum temperatures across a majority of the region March 1-2nd, March 6th, (near and below freezing temperatures) and March 28-30th (teens to 20°F ). Preliminary data also shows that new records were established for observed daily highest maximum temperatures across Minnesota and northern Wisconsin March 10-11th and March 13-15th with high temperatures ranging in the 60s to 70s, and an observed maximum high temperature of 81°F in Little Sioux, Iowa on March 15th. Again on March 16-17th temperatures reached into the 70s and 80s across Minnesota and also in the lower portions of Missouri and southern Illinois. The high temperature in Sioux City reached 90°F on March 16th. Iowa has only seen a monthly temperature extreme of -17°F to 90°F during the month of March in three other years: 1943, 1959, and 1962 (period of record: 1872-2015).
While Iowa, Minnesota, and Wisconsin all witnessed warmer than normal temperatures for March, rankings were not within the top 20 warmest March on record: Iowa saw its 38th warmest March on record (1895-2015 – all states); Minnesota saw its 23rd warmest March on record; and Wisconsin saw its 39th warmest March on record. Despite the daily observed, record-breaking cold spells through March in the eastern states of the region, rankings were also not in the top 20 coldest March on record: Illinois experienced its 44th coldest March on record; Indiana – 37th coldest on record; Kentucky – 49th coldest on record; Michigan – 56th coldest on record; Missouri – 62nd coldest on record; and Ohio – 34th coldest on record. The Midwestern region overall was 1°F below normal, ranking as the 68th coldest March on record.
Dry in the Northwest States of the Region, Wet in the Southeast
Precipitation for the month of March was primarily concentrated along the Ohio River Valley, resulting in Kentucky having its 26th wettest March on record (period of record all states:1895-2015) observing 6.11 inches of precipitation, and Ohio having its 50th wettest March on record observing 3.49 inches of precipitation. Greater than normal accumulated precipitation ranging from 1 to 4 inches fell across the southeast half of Missouri, the southern one-third of Illinois, the southern half of Indiana, the southern two-thirds of Ohio, and all of Kentucky. All other locations saw accumulated precipitation values 1 to 2 inches below normal (Figure 5).
As a percentage of normal, the Ohio River Valley regions were 75 to 200 percent above normal while those locations with values 1 to 2 inches below normal only recorded 10 to 75 percent of normal accumulated precipitation. Iowa ended the month with the largest land area having experienced below normal precipitation, with this land area recording only 10-25 percent of normal accumulated precipitation (Figure 6).
A dry period spanning March 4-21st resulted in an Iowa statewide average of observed precipitation to be only 0.01 inches. The deficit of rainfall across the northwest half of the Midwestern region resulted in Iowa having experienced its 3rd driest March on record only observed 0.56 inches of precipitation. Michigan recorded its 8th driest March on record, observing only 0.78 inches of precipitation, and Minnesota recorded its 13th driest March on record observed only 0.57 inches of precipitation. Wisconsin observed only 0.69 inches of precipitation, ranking March 2015 as Wisconsin’s 10th driest March on record. Illinois, Indiana, and Missouri saw their 41st, 70th, and 69th driest March on record, respectively. Regionally, it was the 34th driest March on record having only observed 2.08 inches of precipitation which is 83 percent of normal.
Total accumulated precipitation ranged from 0.25 inches to 1 inch across the northwest half of the region, with 1 to 8 inches accumulated precipitation across the southeast half of the region. The boot heel of Missouri recorded 8 inches accumulated precipitation, with amounts of 5 to 8 inches falling in southeast Missouri, southern Illinois, southern Indiana and across Kentucky (Figure 7). A system that moved through the Ohio River Valley March 4-5th contributed to the monthly observed accumulated precipitation in the form of snowfall, with 17.1 inches of snow recorded from the event in Lexington, Kentucky (Figure 8). According to NWS-Louisville, Lexington, Kentucky broke its record for the heaviest 2-day snowstorm ever with 17.1 inches of snow, a record that had been upheld since 1943. The Cincinnati area recorded several inches of snow through March 6 from the same system, resulting in short-lived flood warnings after a warm-up period accompanied by rainfall and snow melt.
Accumulated snowfall during March was above normal across most of Missouri, Illinois, Indiana, and Ohio by several inches, and 8 – 16 inches above normal across north-central Kentucky from the March 4-5th snowstorm. From preliminary data, this early March snowstorm across the Ohio River Valley, along with a system that moved through the upper Midwest March 22-24th dropping snowfall in a narrow region from Minneapolis southeast through Chicago and northern Indiana, resulted in some new daily observed snowfall records. Even with the snowfall event March 22-24th that was confined along the Mississippi River Valley from roughly Minneapolis south and along the Illinois and Wisconsin state line, the northwest states in the region saw accumulated snowfall values 2 to 8 inches below normal (Figure 9).
Drought Monitor and Climate Events
March Drought Monitor
As of March 31st, the continued deficit of snowfall and precipitation across the upper Midwest region has resulted in the expansion of the drought status to include all of Minnesota and Wisconsin, along with central Michigan, eastern Iowa, and western Illinois between the Illinois and Wisconsin border south to the intersection of the Iowa, Missouri, and Illinois borders. Minnesota is now classified as moderate drought, long term, with the other areas classified as abnormally dry, short-term drought status. This has heightened danger for fire risk, especially across the southern half of Minnesota.
Climate Events
Those cities in the Upper Peninsula of Michigan, in immediate vicinity of Lake Superior recorded over 150 inches of snowfall for the season November 1st, 2014 to March 31, 2015. As of March 21st, Sault Ste. Marie, Michigan ranked as the snowiest U.S. city having observed 158.7 inches. Total accumulation November 1st, 2014 to March 31st, 2015 for the location was 165.8 inches.
March 18, 2015 marked the 90th anniversary of the Tri-State Tornado. This long-lived, violent tornado event impacted towns from southeast Missouri where the tornado touched down (approximately 20 miles southwest of Annapolis, Missouri), and trekked across southern Illinois and into southwest Indiana where the tornado dissipated northeast of Princeton, Indiana; 625 people lost their lives during the event. March is typically when severe weather season begins to ramp-up across tornado alley, and averages 78 tornadoes a month in the United States over the past 20 years. However, this year as of March 23rd, a severe thunderstorm or tornado watch had not been issued for the month. This is considered a rare occurrence and hasn’t happened since 1970. The severe weather and tornadoes reported during the last full week of March in Oklahoma and Arkansas ended the lapse of tornadoes for the month. Hail was reported in Missouri with this event, with most hail stone reports ranging in size from 1 inch in diameter to 1.75 inches in diameter. Several 2-inch diameter hail reports were documented in Ozark and Shannon counties in Missouri.
The heavy rain and snow that affected most of the southern half of the region in February was followed by above normal temperatures and rain events during the week of March 8-14th 2015. This resulted in snow melt and the addition of more rainfall that led to flooding in the Ohio River Valley. Rainfall events on March 10-11th and March 13-14th heightened flood concerns in the Ohio Valley. Throughout most of the week, the Ohio River was under a flood warning from the Ohio, Kentucky, and West Virginia tri-state area to the mouth of the Mississippi River. The Ohio River at Cincinnati crested early on March 15, 2015 at 57.72 feet which was the first time the river was over 57 feet at the city since 1996. The Wabash River in Indiana was also under a flood warning from Lafayette to the mouth of the Ohio River.
-OBK-
Portions of this report were provided by NWS Louisville, the Iowa Department of Agriculture and Land Stewardship, and Minnesota HydroClim.