MESOSCALE DISCUSSION 1645
   NWS STORM PREDICTION CENTER NORMAN OK
   0220 PM CDT SUN AUG 31 2014

   AREAS AFFECTED...KS...NE...IA...MN...SD...MO

   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

   VALID 311920Z - 312045Z

   PROBABILITY OF WATCH ISSUANCE...80 PERCENT

   SUMMARY...RISK OF SEVERE THUNDERSTORMS WITH LARGE HAIL...HIGH
   WINDS...AND A TORNADO OR TWO EXPECTED INCREASE ACROSS ERN NEB/NRN
   KS/WRN IA AND SRN MN INTO THIS EVENING. A WATCH WILL LIKELY BE
   NEEDED ACROSS SOME OF THESE AREAS IN THE NEXT 1-2 HOURS.

   DISCUSSION...A PROGRESSIVE MID/UPPER TROUGH AND ASSOCIATED 40-50KT
   MID-LEVEL WIND MAX SPREADING OVER THE CENTRAL HIGH PLAINS THROUGH
   THIS EVENING WILL ACT TO ENHANCE DEEP-LAYER ASCENT ALONG AN
   ADVANCING COLD FRONT CURRENTLY SITUATED FROM WRN MN TO NRN KS. A
   WARM AND SUFFICIENTLY MOIST AIRMASS AHEAD OF THE FRONT AND STRONGER
   MID-LEVEL FORCING WILL CONTRIBUTE TO A CORRIDOR OF STRONG
   INSTABILITY WITH SBCAPE VALUES GENERALLY AOA 2000 J/KG. ISOLATED
   ONGOING CONVECTION...FROM WRN IA TO SRN MN...APPEARS TO BE
   ASSOCIATED WITH A LEADING LOW-AMPLITUDE DISTURBANCE AHEAD OF THE
   STRONGER TROUGH. WHILE SOME OF THESE ELEVATED STORMS MAY POSE A
   THREAT FOR HAIL GIVEN ANTECEDENT RELATIVELY STEEP MID-LEVEL LAPSE
   RATES...THE GREATER SEVERE WEATHER RISK SHOULD DEVELOP TO THE WEST
   OF THE ONGOING CONVECTION...ACROSS ERN NEB AND NRN KS...OVER THE
   NEXT FEW HOURS.

   ROBUST CONVECTIVE DEVELOPMENT MAY BE FOCUSED PRIMARILY ALONG AND
   IMMEDIATELY BEHIND THE SURFACE COLD FRONT GIVEN RELATIVELY STRONG
   INHIBITION ALONG AND AHEAD OF THE BOUNDARY. THIS ACTIVITY WILL TEND
   TO ORGANIZE INTO LINE SEGMENTS AND SOME SUPERCELL STRUCTURES
   COINCIDENT WITH THE STRENGTHENING OF DEEP-LAYER SHEAR THROUGH
   EVENING. IF MORE DISCRETE STORMS INITIATE AHEAD OF THE COLD
   FRONT...PERHAPS NEAR REMNANT OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES
   IN THE WAKE OF EARLIER CONVECTION OVER IA/MN...THE POTENTIAL FOR
   LOCALLY STRONGER LOW-LEVEL SHEAR AND REDUCED LCL HEIGHTS IN THESE
   AREAS COULD SUPPORT A GREATER TORNADO RISK...PROBABLY WITHIN AN HOUR
   OR TWO OF STORM INITIATION.

   EVOLVING MCS/SQUALL LINE OVER ERN NEB/NRN KS WILL MOST LIKELY CROSS
   INTO WRN IA...AND EXTREME NWRN MO...DURING THE EVENING HOURS WITH A
   CONTINUING CHANCE TO PRODUCE DAMAGING WINDS AND HAIL. ANY TORNADO
   RISK SHOULD LESSEN AS THIS EVOLUTION OCCURS.

   ..CARBIN/HART.. 08/31/2014


   ATTN...WFO...ARX...MPX...DMX...EAX...FSD...OAX...TOP...ICT...
   GID...GLD...

   LAT...LON   44639605 44879567 45039501 45039420 44789370 43979276
               43319286 42709339 41999435 41379479 40989501 40669528
               40479548 39929602 39449734 39149868 39179938 39389981
               39579986 40029978 40539916 40959870 41489816 41859790
               42129771 42549749 43169709 43889678 44639605