Seemingly like a broken record, yet another day of severe weather is on tap across the Plains and Mississippi Valley today. Destructive tornadoes, very large hail and damaging winds are all likely once again from Texas to Michigan. Tornado Watches and Severe Thunderstorm Watches stretch across southern Oklahoma, and from northeastern Arkansas to northern Indiana. This includes Ardmore, Okla., Fort Smith, Ark., Memphis, Tenn., Paducah, Ky., Terre Haute, Ind., and South Bend, Ind. The cause of the storms is the same storm system that has wreaked havoc on the Plains since the start of the weekend. A cold front stretching from the Upper Mississippi Valley into central Oklahoma separates very warm and humid air streaming northward from the Gulf of Mexico from cooler and drier air streaming southward and eastward from the Rockies. Temperatures have been jumping into the 80s ahead of the storm, fueling the storms' development, and coupled with a great deal of spin in the atmosphere, tornadoes have been the result. Fifty-five possible tornadoes have been reported since Saturday, including a massive tornado that spun across Moore, Okla., killing 91 and injuring hundreds. It has been preliminarily rated at EF-4. The storm threat will shift slightly to the south and east, targeting southeastern Oklahoma and northern Texas, but the results will be much the same as in the past few days. Large and powerful tornadoes are likely, along with destructive winds of 70 to 80 mph and hail to the size of baseballs and softballs. The threat is sufficiently high that the Storm Prediction Center has made today the fourth straight day in which an elevated Moderate Risk for severe weather has been issued. This heightened threat area includes the Dallas-Fort Worth Metroplex, Waco and Texarkana, Texas, and Shreveport, La. Beyond that, a large section of the Central U.S. is at risk for strong to severe thunderstorms, including Austin, Texas, Little Rock, Ark., St. Louis, Chicago, Indianapolis, Toledo, Ohio, and Detroit. Beyond the severe threat, heavy rain is likely to make flooding a major concern. Locally heavy rain could total 3 inches or more. Flash Flood and Flood Watches are in effect across eastern Oklahoma and western Arkansas, as well as northern Minnesota, northwestern Wisconsin and northeastern North Dakota. If you come across a flooded roadway, do not attempt to cross it, as it is likely deeper than it appears. It`s best to "Turn Around, Don`t Drown." Make sure that you download the WeatherBug app on your smart phone. The mobile app now includes Spark Lightning Alerts, a GPS-based lightning detection feature providing you the location of the closest lightning strike, so you can Know Before the storm hits. Click here for the link to download. Be sure to keep WeatherBug active to receive the latest severe weather in your neighborhood and get the latest updates anywhere on Twitter. What do you think of this story? Click here for comments or suggestions.