On Sunday, November 17th, 2013, an outbreak of deadly tornadoes occurred across the upper midwest region of the United States. 73 tornadoes were confirmed across Illinois, Indiana, Kentucky, Michigan, Missouri, and Ohio. Two of the seventy-three tornadoes were violent, of which both earned damage ratings on the Enhanced Fujita Scale of EF-4 (166-200mph winds). Both of the EF-4 rated tornadoes occurred in the State of Illinois.
Forecast lead time was well in advance of the event, as initial forecasts by the NOAA Storm Prediction Center were issued as far as five days in advanced. Forecasts leading up to the outbreak indicated concern for a multi-faceted event across portions of the upper midwest. Storm related hazards included the potential for destructive tornadoes, large hail (≥1.00″), and widespread damaging winds (≥58mph).
A potent mid-level jet maximum near 100 knots was forecast to move across the middle Mississippi River Valley on Sunday, November 17th. Morning radiosonde observations across the upper midwest indicated very strong vertical wind shear, in addition to rich low-level moisture.
The combination of deep moisture, strong wind shear, and thermal instability was favorable for significant severe weather ahead of and along the rapidly eastward moving cold front. Storm motions approached highway speeds between 70-80mph across the upper midwest on November 17th.
As early as 8:40am CST in the morning, the Storm Prediction Center issued Particularly Dangerous Situation (PDS) tornado watches across portions of Illinois, Missouri, and southern Wisconsin. Additional PDS tornado watches were issued downstream into Indiana, Michigan, and Ohio by the latter half of the morning as the low pressure system continued to advance eastward.
|Number of Tornadoes per state by EF-Scale rating|
In addition to the 73 confirmed tornadoes, widespread and destructive winds occurred across the upper midwest and into the eastern Ohio River Valley. Over 500 reports of severe wind (≥58mph) occurred on November 17th. The highest reported wind gusts were 85mph, of which these reports were observed in Crown Point and Swayzee, Indiana; and Bowling Green, Ohio.
|Top 15 Observed Wind Reports|
|85mph||1mi ESE Crown Point||Indiana|
|83mph||3mi NE Pines||Indiana|
|80mph||1mi S Markle||Indiana|
|80mph||1mi S Markle*||Indiana|
|80mph||5mi SW Bloomington||Indiana|
|80mph||3mi E Ashville||Ohio|
|75mph||3mi NNE Melbourne||Ohio|
|*Two separate 80mph wind reports occurred 5 minutes apart|
The largest hailstone observed throughout the tenure of the event was softball size (4.00″ in diameter) near Bloomington, Illinois. The majority of hail reports occurred across Illinois; however, only 42 reports of severe hail were observed and/or reported throughout the event and its entirety.
|Top 5 Hail Reports on November 17th|
|Hail size (inches)||City||State|
|4.00”||2mi SW Bloomington||Illinois|
|2.50”||1mi N Venedy||Illinois|
The tornado that impacted Washington, Illinois, was given a rating of a high-end EF-4 with maximum estimated winds of 190mph. A width of half a mile, this long-track tornado had a path of 46.2 miles as it leveled neighborhoods in the town of Washington. Several trees were also snapped in half and debarked. Three fatalities occurred, in addition to 121 injuries.
The second EF-4 tornado occurred in New Minden, Illinois, with maximum estimated winds of 180mph. The National Weather Service damage survey concluded the EF-4 rating given that a well built farm house was completely destroyed and swept away by the tornado. This tornado tracked for 10.6 miles, and caused two fatalities.
In all, 5 deaths and 125 injuries were reported throughout the tenure of the event. The EF-4 tornado that impacted Washington, Illinois, was the strongest tornado documented in the State of Illinois during the month of November since verified records began in 1950. A total of 149 tornado warnings were issued, in addition to 213 severe thunderstorm warnings, 5 flash flood warnings, and 27 special marine warnings.