A dangerous weather setup is shaping up over the Midwest this weekend. Powerful storms could usher tornadoes, hail, and lighting into the region, putting millions at risk. Heavy rain could also cause flash floods as it falls on saturated soil in areas already grappling with historic flooding.
May is prime time for severe weather in the Plains, and all the elements are coming together for a wild weekend. The National Oceanic and Atmospheric Administration (NOAA) is calling for enhanced and severe risk of tornadoes, hail, thunderstorms, and other atmospheric maladies starting on Friday and running into early next week for locations from Texas all the way north to Minnesota and as far east Pennsylvania. But the bullseye for the best odds of bad weather will shift around in the coming days.
On Friday, the risk of tornadoes and hail “the size of baseballs” are highest in parts of Nebraska and central Texas, according to NOAA. Parts of the Mid-Atlantic and Ohio River Valley could also be severe weather hot spots. Saturday will see the risk shift to the east and Jason Furtado, a meteorology professor at the University of Oklahoma, noted that both Dallas and Little Rock are in the danger zone. Monday, the risk expands to cover areas that include Oklahoma City and Wichita. None of this is to say those cities are going to turn into the Day After Tomorrow. But if you live there or anywhere else in regions at-risk of severe weather, it’s worth keeping an eye on the local forecast and heeding all warnings.
Beyond tornadoes and hail, the storms could also unleash heavy rain. Furtado said anywhere for 4-6 inches of rain could fall over the next 5-7 days . Locally higher amounts are possible, and in a waterlogged region where soils are already saturated and rivers are already swollen, it’s a recipe for flash floods on top of the already devastating flooding that’s hit the Midwest this spring.
“We need to take the flooding threat seriously,” Furtado told Earther in an email.
The risk of severe weather is building due to a few key ingredients. The first is a powerful jet stream, which is currently steering a series of strong, offseason storms into California. As the jet stream moves over the U.S., it will start to dip through the southern Rockies and then take a sharp swing up in the central U.S. due to a big ridge of high pressure over the Southeast.
“The combination of strong clockwise motion from the high pressure in the Southeast and the counterclockwise motion from the storms coming into the western US are acting as a ‘moisture pump’ into the central U.S., creating lots of instability, rain, and of course severe weather,” Furtado said.
The setup has its roots in the tropical Pacific as well as the abnormally warm Arctic, which is causing the jet stream to get really wavy and create what Furtado called a “stuck” weather pattern. In the case of this stuck pattern, areas on the edge of the jet stream will have to contend with severe weather while those living to the south of the jet stream will be stuck with freakish triple-digit heat. There are a few lines of research suggesting wavy jet stream patterns could be influenced by climate change and the rapidly warming Arctic, in particular, though no work has been done to attribute this current setup.