MESOSCALE DISCUSSION 1056
   NWS STORM PREDICTION CENTER NORMAN OK
   0349 AM CDT THU JUN 18 2015

   AREAS AFFECTED...WRN AND CENTRAL NEB

   CONCERNING...SEVERE THUNDERSTORM WATCH 309...

   VALID 180849Z - 181045Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 309
   CONTINUES.

   SUMMARY...ISOLATED RISK FOR DAMAGING WINDS AND HAIL CONTINUES ACROSS
   NWRN NEB ATTM...AND MAY SPREAD ACROSS WRN AND PORTIONS OF CENTRAL
   NEB WITH TIME AS THE BOWING MCS CONTINUES MOVING SEWD.

   DISCUSSION...LATEST RADAR LOOP SHOWS A RELATIVELY
   WELL-ORGANIZED/BOWING LINE OF STORMS MOVING SEWD ACROSS NWRN NEB AT
   AROUND 40 KT.  THE STORMS ARE OCCURRING WITHIN AN ENVIRONMENT
   FEATURING AMPLE INSTABILITY /500-1000 J/KG MIXED-LAYER CAPE/...NEAR
   THE NOSE OF A 30 KT LOW-LEVEL JET.  

   THE FASTEST-MOVING PORTION OF THE BOW APPEARS LIKELY TO REACH THE
   SERN CORNER OF THE WW BETWEEN 10Z AND 1030Z.  HOWEVER...A MUCH LESS
   UNSTABLE AIRMASS IS INDICATED INTO CENTRAL NEB BY LATEST OBJECTIVE
   ANALYSES...WITH THE ERN BORDER OF THE WW LOCATED WITHIN A STRONG N-S
   GRADIENT OF INSTABILITY.  WITH GREATER INSTABILITY RESIDING OVER WRN
   NEB...AND THE HIGH-PLAINS LLJ PROGGED TO VEER SLIGHTLY WITH TIME TO
   A MORE SSWLY DIRECTION...MAIN PUSH OF THE CONVECTION -- AND
   ASSOCIATED/LINGERING SEVERE RISK -- MAY SPREAD IN A MORE SSEWD
   DIRECTION AND REMAIN OVER WRN NEB.  THIS -- COMBINED WITH LIKELIHOOD
   THAT SEVERE RISK GRADUALLY DIMINISHES WITH TIME -- SUGGESTS
   UNCERTAINTY WITH RESPECT TO NEW WW ISSUANCE.  ATTM...IT APPEARS AT
   LEAST POSSIBLY THAT SMALL LOCAL EXTENSIONS IN AREA MAY BE SUFFICIENT
   TO CONTAIN ANY RESIDUAL SEVERE RISK BEYOND THE CURRENT CONFINES OF
   THE WATCH.

   ..GOSS.. 06/18/2015


   ATTN...WFO...GID...LBF...GLD...BOU...CYS...

   LAT...LON   42960018 42999927 42049868 40909831 40389843 40279924
               40090082 40240187 41160258 41990288 41970219 41900131
               42320031 42960018