An area of low pressure is slowly developing over the Central Plains as it tracks toward the Great Lakes this upcoming weekend, acting as the main instigator for this next round of severe weather across portions of the Central US. The combination of this low pressure and the fronts associated with it will provide lift, pairing with moisture, instability, and wind shear in increasing the severity of these storms.
Storms that are currently tracking east over central Nebraska will weaken midday, allowing for the atmosphere to destabilize. The best risk for severe weather this afternoon and tonight will be across eastern Nebraska into southern South Dakota. Throughout the day, we’ll be tracking a line of thunderstorms slowly moving east through the central Dakotas associated with an upper-level low. Some of these storms in South Dakota will turn severe beginning in the afternoon. To the south, it’s not until the evening when several supercell or discrete thunderstorms will rapidly develop across eastern Nebraska. It’s these storms that will pose the greatest risk for tornadoes. Then overnight, those scattered storms will evolve into a line, containing strong to damaging winds as they track into central Iowa and northern Missouri by daybreak on Thursday. That line will extend up through Minnesota as the upper low tracks east. Isolated severe storms will be possible Thursday morning, but the main concern by this point will be localized flash flooding.
A separate piece of energy farther south will instigate the development of scattered showers and thunderstorms Wednesday evening down towards Missouri and Arkansas. With modest wind shear sweeping through overhead, isolated severe weather will be seen throughout this region. Strong winds and large hail will be the main risks with any of these storms that turn severe in this part of the country.
On Thursday we’ll see the synoptic scale low pressure track farther to the north and east, shifting the risk for severe weather towards the Upper Midwest, likely right over the Quad Cities. A couple tornadoes, damaging winds, and large hail will remain the threat with any of the severe storms. There will likely be two lines of storms that pass through the Midwest on Thursday. The first line will be around already at the start of the day, spanning from Minnesota through Iowa. Then in the afternoon, it will track to the east and into the western Ohio River Valley and Great Lakes. Meanwhile back toward the west, the low pressure will likely instigate a secondary round of strong to severe thunderstorms in and near the Quad Cities beginning in the mid-afternoon and persisting into the first half of the overnight hours.
By Friday, the severe weather threat will be focused across the Ohio and Tennessee River Valleys. By this point in time, the storms don’t look to be as organized with a widespread line of intense storms. Instead, storms will be more scattered and in the hit or miss variety, containing generally damaging winds and hail.
We’ll update you with more precise timing and details in the upcoming days as this multi-day risk of severe weather sets up.