The conditions necessary to create "some big storms" will occur Wednesday and Thursday, a forecaster warned, cautioning millions of residents in the central United States to be aware of worsening weather. Large hail, damaging winds, and several tornadoes were possible Wednesday in the south-central part of the country before the focus shifts to the mid-Mississippi River Valley, including the state of Illinois. "Thursday will be the bigger day, but there's still potential [Wednesday] for significant storms in northeastern Oklahoma, eastern Kansas, and perhaps into Missouri," said Greg Carbin, the warning coordination meteorologist for the Storm Prediction Center in Norman, Oklahoma. "We're not exactly sure how things will evolve in that corridor." Heat, humidity, instability, an approaching front, and the jet stream will all contribute to steadily worsening weather. "By Thursday, it looks like all those ingredients come together," Carbin said. "You can really blow up some big storms." The Storm Prediction Center said Wednesday's storms in an area from Wichita, Kansas to Joplin, Missouri and on either side of the Kansas-Oklahoma border could be significant - defined as having 5-centimeter hail, 120-kilometer-per-hour winds, and tornadoes rated at EF2 or higher. On Thursday, similar storms were forecast for a large area from the Arkansas-Missouri border to southern Wisconsin, including the cities of Chicago and Saint Louis. Areas that do not see strong storms could see heavy rain instead. The week already has seen some severe weather in the region. Emergency officials said a tornado touched down briefly Tuesday night in southeastern Kansas, and hail and high winds caused problems from Saint Louis to southwestern Indiana.
