SIOUX CITY, Iowa (KCAU) – (Updated 4/4/23-3 PM) – Communities across the Midwest and southern US have just begun picking up the pieces from last Friday’s storms, which produced hundreds of severe weather reports, including several destructive, long-track EF2+ tornadoes. Unfortunately, many of the hardest hit areas are bracing for the threat of another potentially significant severe weather outbreak Tuesday and Wednesday.
The first round of severe weather potential comes Tuesday afternoon and into the overnight hours of Wednesday morning.
The threat in east/east-central Iowa into Illinois comes in multiple rounds. The initial round begins with isolated supercells developing through the afternoon and early evening hours across the risk zone. A cap in place, however, may inhibit some storm growth initially, but any storms that get going pose the risk of large hail, strong tornadoes, and damaging winds. Storms increase in coverage through the evening, and into the early overnight hours, this timeframe poses the highest risk of supercell activity and strong tornadoes. Eventually, through the overnight hours, a trailing cold front behind the main low pressure system catches up and storms transition into a more linear mode and the threat shifts to damaging winds, hail, and a few tornadoes.
The severe threat also ramps up into much of Arkansas/eastern Oklahoma and southern Missouri. This threat comes in two rounds. The first of which looks to be in the evening/early overnight hours bring primarily scattered supercell mode storms and the greatest potential for tornadoes, some possibly strong/violent long-track and very large hail. A second round of storms, more than likely a squall line which sets up along the cold front looks to move across the area in the early morning hours Wednesday.
This moderate risk encompasses over 56,000 square miles and over 3 million people, including the cities of Springfield, MO; Cedar Rapids, Davenport, Waterloo, and Iowa City, IA.
Outside of the moderate risk zone, a large swath of these regions are under an enhanced risk, meaning scattered to numerous severe storms, potentially packing tornadoes, some significant, large hail, and damaging winds are possible, if not likely. This zone includes over 110,000 square miles or nearly 11.5 million people from Texas to Wisconsin, including: St Louis, MO; Madison, WI; Little Rock, AR; and Aurora, IL.
Another large portion, spanning over an area of over 140,000 square miles and nearly 21 million in central/southern/Midwest US are under a slight risk of severe weather, with isolated to scattered severe storms, including Chicago; Milwaukee; Kansas City, MO; Tulsa, OK; and Garland, TX, with all modes of severe weather a possibility.
Another nearly 110,000 square miles and almost 13.5 million people, including in major cities like Indianapolis; Dallas, TX; Memphis, TN; Plano, TX; and Fort Wayne, IN are also at risk of a few isolated severe storms with the main threat in those areas being damaging winds.
On the other side of this storm system, through parts of the upper Midwest, including parts of Nebraska; the Dakotas, and parts of Minnesota, a significant winter storm is expected. Heavy snow and blizzard conditions are forecasted with Blizzard and Winter Storm Warnings already in place.
The severe threat shifts farther east and a bit more northward for Wednesday, with more hard hit areas from Friday’s storms under the threat of potentially significant tornadoes, destructive winds, and large hail.
The Storm Prediction Center has highlighted a large swath of the Midwest and into the south, including the entire state of Indiana, much of the state of Ohio and lower peninsula of Michigan and portions of Kentucky, Tennessee, Missouri, Mississippi, and Arkansas for an ENHANCED risk for severe weather.
Best potential for severe weather will be in the timeframe of Wednesday morning through Wednesday evening with multiple rounds of storms increasingly likely. Several modes of storms are possible, including scattered supercells and clusters of supercells and non supercells initially, eventually organizing into a more linear mode along the passing cold front. Although there is still uncertainty on whether or not discrete cells/super cells will be maintained as the system moves through. If supercells/discrete cells do hold together, a highly sheared environment anticipated over the threat area would be conducive to a few potentially strong/significant tornadoes. Regardless of storm mode, the threat for damaging/destructive winds, large hail, and a few weaker tornadoes as the storms roll through.
Here in Siouxland, we mostly dodge both portions of this potent spring storm with just some light rain and possibly a few snow showers expected through Wednesday morning. We also see temperatures fall into the 30s to around 40° for Wednesday.
Anyone in the areas at risk for severe weather, Tuesday, through the day Wednesday, should have several ways to receive warnings, stay informed of the latest updates on watches/warnings via your local meteorologists, and have a plan on where to go and what to do if/when severe weather strikes. Be safe and stay weather aware out there!
For the latest weather updates, especially with spring severe weather season underway, visit KCAU 9’s Weather page by clicking here.
And with winter weather still hanging on here in Siouxland, it pays to be prepared. For a variety of resources, click here.