The Midwest and Great Plains have battled historic storms and flooding over the last few weeks seemingly “stuck” in a dangerous weather pattern — more than 250 tornadoes have struck since May 17, according to the Omaha World-Herald’s reporting from the National Weather Service, most happening in “swarms” of 25 or more at a time, including the latest deadly round in Dayton, Ohio and severe storms in Chicago yesterday.
Why This Matters: These storms are unprecedented. In the past week alone, according to CBS News, nearly 20 people have been killed and hundreds more injured by tornadoes and flooding across a wide swath of the country, and flood waters are setting records along the Mississippi, Missouri, Illinois and Arkansas Rivers, and tornadoes threatening homes and businesses in Idaho, Colorado, Minnesota, Indiana, Ohio, Illinois, Iowa, Nebraska, Arkansas, Oklahoma, Kansas, and Missouri. And, according to the Storm Prediction Center, this pattern of high pressure in the Southeast (which is bringing raging heat there) and cold in the Rockies shows no sign of moving — which can only mean more damage and destruction ahead for the region. There is increasing evidence that these long-lasting, unusual weather patterns are caused by climate change altering the jet stream in a way that creates extreme and long-lasting weather anomalies.
Recent Storms By the Numbers (AP):
- “Storm reports posted online by the National Weather Service’s Storm Prediction Center showed that 14 suspected tornadoes touched down in Indiana, 12 in Colorado and nine in Ohio. Seven were reported in Iowa, five in Nebraska, four in Illinois and three in Minnesota, with one in Idaho.”
- “Monday marked the record-tying 11th straight day with at least eight tornadoes in the U.S., said Patrick Marsh, a Storm Prediction Center meteorologist. The last such stretch was in 1980.”
- Marsh also said, “Outbreaks of 50 or more tornadoes are not uncommon, having happened 63 times in U.S. history, with three instances of more than 100 twisters,”
- This week’s “swarm” was unusual because it happened over a particularly wide geographic area and came amid an especially active stretch.
What’s Different Now? According to the National Severe Storms Lab (Omaha World-Herald):
- In the 1970s, it was more typical to have one day a year with 25 or more tornadoes. In recent years, that’s jumped to four days in a year, “a really large change,” said Harold Brooks, a senior research scientist with the National Weather Service’s National Severe Storms Laboratory.
A Sliver of Good News: According to Brooks, in the 1970s, there were about 150 days per year in which an EF-1 or stronger tornado occurred. Now that’s down to less than 100 days.
May 28, 2019 » EF-1, Flooding, National Severe Storms Laboratory, National Weather Service, severe storms, tornadoes