Here is a weather statement issued by the National Weather Service this morning:

PUBLIC SEVERE WEATHER OUTLOOK  

   
   ...SEVERE THUNDERSTORM OUTBREAK EXPECTED FROM THE EASTERN HALF OF
   THE PLAINS INTO THE UPPER MISSISSIPPI VALLEY THIS AFTERNOON AND
   TONIGHT...
  
   THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING
   WIDESPREAD DAMAGING THUNDERSTORM WINDS...STRONG TORNADOES AND LARGE
   HAIL OVER A LARGE PART OF THE EASTERN PLAINS AND THE UPPER
   MISSISSIPPI VALLEY THIS AFTERNOON THROUGH TONIGHT.
  
   THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE
  
          MUCH OF IOWA
          CENTRAL AND EASTERN KANSAS
          SOUTHERN AND CENTRAL MINNESOTA
          WESTERN AND NORTHERN MISSOURI
          CENTRAL AND EASTERN NEBRASKA
          WESTERN...CENTRAL AND NORTHERN OKLAHOMA
          EASTERN SOUTH DAKOTA
          WESTERN AND CENTRAL WISCONSIN
  
   ELSEWHERE...SCATTERED SEVERE STORMS ARE ALSO POSSIBLE FROM NORTHWEST
   TEXAS THROUGH THE MID MISSISSIPPI VALEY TO THE GREAT LAKES.
  
   AN UNSEASONABLY STRONG JET STREAM DISTURBANCE NOW OVER NEW MEXICO
   ...WITH WIND SPEEDS IN EXCESS OF 130 MPH...WILL SWEEP RAPIDLY NORTH
   NORTHEAST ACROSS THE PLAINS STATES TODAY...AND INTO THE UPPER
   MISSISSIPPI VALLEY EARLY FRIDAY.
  
   IN RESPONSE...A STRONG SURFACE LOW NOW IN WESTERN KANSAS WILL
   FURTHER STRENGTHEN AS IT MOVES NORTH TO THE NEBRASKA-SOUTH DAKOTA
   BORDER THIS EVENING...AND INTO NORTH DAKOTA EARLY FRIDAY.
  
   AHEAD OF THE LOW...A BROAD CURRENT OF VERY WARM AND HUMID AIR WILL
   SPREAD FROM THE SOUTH CENTRAL STATES INTO NEBRASKA...EASTERN SOUTH
   DAKOTA AND THE UPPER MISSISSIPPI VALLEY.
  
   THE COMBINATION OF UNUSUALLY STRONG WINDS WITH INCREASINGLY WARM AND
   HUMID AIR WILL SET THE STAGE FOR THE DEVELOPMENT OF WIDESPREAD
   INTENSE THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT...BOTH ALONG
   THE PATH OF THE SURFACE LOW...AND FARTHER EAST AND SOUTH BENEATH THE
   MAIN JET STREAM DISTURBANCE.
  
   SOME OF THE STORMS WILL BE SUPERCELLS...LONG-LIVED...ROTATING STORMS
   THAT COULD SPAWN STRONG TORNADOES IN ADDITION TO LARGE HAIL.  MANY
   OF THE STORMS...ESPECIALLY THIS EVENING...LIKELY WILL ORGANIZE INTO
   LONG...ARC-SHAPED BANDS.  THESE BANDS WILL PRODUCE BROAD SWATHS OF
   DAMAGING OUTFLOW /DERECHO/ WINDS.
  
   THIS IS POTENTIALLY A VERY DANGEROUS SITUATION. THOSE IN THE
   THREATENED AREA ARE URGED TO REVIEW SEVERE WEATHER SAFETY RULES AND
   TO LISTEN TO RADIO...TELEVISION...AND NOAA WEATHER RADIO FOR
   POSSIBLE WATCHES...WARNINGS...AND STATEMENTS LATER TODAY.