MESOSCALE DISCUSSION 1451
   NWS STORM PREDICTION CENTER NORMAN OK
   0543 PM CDT FRI JUL 17 2015

   AREAS AFFECTED...NERN NEB

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

   VALID 172243Z - 180015Z

   PROBABILITY OF WATCH ISSUANCE...40 PERCENT

   SUMMARY...THE POTENTIAL FOR ISOLATED SEVERE WEATHER APPEARS TO BE
   INCREASING ACROSS THE DISCUSSION AREA THIS EVENING.  CONVECTIVE
   TRENDS ARE BEING MONITORED FOR A POSSIBLE WATCH.

   DISCUSSION...A WSW-ENE-ORIENTED BAND OF CONVECTION HAS RECENTLY
   MATURED INTO TSTMS OVER ANTELOPE...SRN PIERCE AND NRN MADISON
   COUNTIES IN NERN NEB AS OF 2230Z.  MESOANALYSIS AND VISIBLE
   SATELLITE SUGGEST THAT A SUBTLE CONFLUENCE ZONE BETWEEN ONL AND OFK
   ALONG WITH THE REMOVAL OF WEAK CAPPING WITHIN A COMPARATIVELY HOTTER
   AND DEEPER-MIXED PBL OVER CNTRL NEB /AROUND ODX/ MIGHT BE
   CONTRIBUTING FACTORS TO THIS NEW STORM DEVELOPMENT.

   IT REMAINS UNCERTAIN AS TO HOW MANY STORMS WILL ULTIMATELY DEVELOP
   WITHIN THIS REGIME DUE TO THE APPARENT ABSENCE OF ANY LARGE-SCALE
   FORCING MECHANISMS.  NONETHELESS...THE PRESENCE OF A VERY MOIST AND
   EXTREMELY UNSTABLE AIR MASS /I.E. RAP-BASED MLCAPE VALUES ESTIMATED
   IN THE 3500-4500+ J/KG RANGE/ COUPLED WITH A MODESTLY SHEARED
   ENVIRONMENT WILL SUPPORT SUPERCELL MORPHOLOGIES WITH AN ATTENDANT
   RISK FOR LARGE HAIL AND LOCALLY DAMAGING WINDS.

   A CONTINUED INCREASE IN STORM COVERAGE AND MODE TRANSITION TO
   SUPERCELLS COULD WARRANT A WATCH.

   ..MEAD.. 07/17/2015


   ATTN...WFO...FSD...OAX...GID...LBF...

   LAT...LON   41699866 42069874 42559841 42699780 42659717 42509672
               42079642 41639654 41319694 41159760 41279842 41699866