DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0717 AM CDT MON MAY 20 2013
   
   VALID 201300Z - 211200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
   PARTS OF NORTH TX...CENTRAL AND EASTERN OK...NORTHWEST AR...EXTREME
   SOUTHEAST KS...AND SOUTHERN MO....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX INTO MUCH OF
   THE UPPER MS VALLEY AND GREAT LAKES REGION....
   
   ...TX/OK/AR/KS/MO...
   MORNING WATER VAPOR LOOPS SHOW A BROAD UPPER TROUGH OVER THE WESTERN
   AND CENTRAL STATES...WITH A PROGRESSIVE SHORTWAVE TROUGH TRACKING
   EASTWARD ACROSS NORTHERN NM.  THIS FEATURE WILL MOVE INTO THE
   SOUTHERN PLAINS BY EARLY AFTERNOON...HELPING TO INITIATE ANOTHER
   ROUND OF STRONG TO SEVERE THUNDERSTORMS OVER THE SOUTHERN PLAINS.
   
   A SURFACE COLD FRONT CURRENTLY EXTENDS ROUGHLY FROM LTS-BVO.  THIS
   FRONT IS LIKELY TO MOVE SLIGHTLY SOUTHEASTWARD TODAY AND WILL
   PROVIDE THE FOCUS FOR AFTERNOON THUNDERSTORM DEVELOPMENT.  VARIOUS
   MESOSCALE MODELS DIFFER ON TIMING OF STRONG/SEVERE STORMS...BUT
   AGREE ON STORMS FORMING OVER CENTRAL OK BY ABOUT 20Z AND BUILDING
   QUICKLY NORTHEASTWARD INTO SOUTHEAST KS AND WESTERN MO.  THE INITIAL
   STORMS WILL LIKELY BE SUPERCELLUAR WITH VERY LARGE HAIL...DAMAGING
   WINDS...AND TORNADOES POSSIBLE.  THOSE STORMS THAT FORM OVER
   SOUTHERN OK INTO NORTH TX APPEAR TO HAVE THE GREATEST CHANCE OF
   REMAINING DISCRETE AND POSING A RISK OF SIGNIFICANT SEVERE WEATHER
   FOR SEVERAL HOURS INTO THE EVENING.  MEANWHILE...STORMS THAT FORM
   FROM CENTRAL OK NORTHEASTWARD INTO SOUTHEAST KS AND MO APPEAR LIKELY
   TO ORGANIZE INTO BROKEN LINES AND CLUSTERS BY EARLY EVENING CAPABLE
   OF WIDESPREAD DAMAGING WINDS...LARGE HAIL...AND A FEW TORNADOES. 
   SIMILAR TO YESTERDAY...MID LEVEL LAPSE RATES OF 7.5-8.0 C/KM...VERY
   LARGE CAPE...AND FAVORABLE SHEAR VALUES WILL POSE A RISK OF ISOLATED
   STRONG TORNADOES ACROSS PORTIONS OF THE MODERATE RISK AREA.
   
   ...UPPER MS VALLEY AND WESTERN GREAT LAKES...
   EARLY VISIBLE SATELLITE IMAGERY SHOWS ONLY BROKEN CLOUD COVER OVER
   PARTS OF IA/WI EASTWARD INTO MI/OH.  RELATIVELY STRONG DAYTIME
   HEATING AND LITTLE CAP SHOULD RESULT IN SCATTERED THUNDERSTORMS
   TODAY AND TONIGHT TO THE EAST OF A SURFACE LOW OVER MN.  MLCAPE
   VALUES OF 1500-2000 J/KG WILL PROMOTE VIGOROUS UPDRAFTS IN THIS
   REGION...WHILE SUFFICIENTLY STRONG VERTICAL SHEAR HELPS TO ORGANIZE
   THE CONVECTION.  PRESENT INDICATIONS ARE THAT MULTIPLE
   LINES/CLUSTERS OF THUNDERSTORMS WILL AFFECT THIS REGION...WITH A FEW
   SUPERCELLS POSSIBLE.  HAIL AND DAMAGING WINDS ARE THE MAIN
   THREATS...BUT ISOLATED TORNADOES CANNOT BE RULED OUT.
   
   ...TX...
   SOUTH OF THE MODERATE RISK AREA IN TX...CONFIDENCE IS A LITTLE
   HIGHER TODAY COMPARED TO LAST FEW DAYS THAT ISOLATED STORMS WILL
   FORM ALONG THE DRYLINE.  ANY STORM THAT CAN FORM IN THIS AREA WILL
   POSE A RISK OF VERY LARGE HAIL AND DAMAGING WINDS FOR A FEW HOURS
   THIS EVENING.
   
   ..HART/LEITMAN.. 05/20/2013