MESOSCALE DISCUSSION 0977

        MESOSCALE DISCUSSION 0977     NWS STORM PREDICTION CENTER NORMAN OK     1050 AM CDT WED MAY 30 2012          AREAS AFFECTED...CNTRL AND ERN NEB          CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE           VALID 301550Z - 301715Z          PROBABILITY OF WATCH ISSUANCE...40 PERCENT          SUMMARY...AN ISOLATED LARGE HAIL THREAT ASSOCIATED WITH ELEVATED     THUNDERSTORMS WILL CONTINUE TO MOVE EWD ACROSS SCNTRL NEB INTO EARLY     THIS AFTERNOON. TRENDS WILL CONTINUED TO BE MONITORED FOR THE     POSSIBILITY OF WW ISSUANCE.          DISCUSSION...A CLUSTER OF STRONG THUNDERSTORMS IS ONGOING JUST TO     THE EAST OF NORTH PLATTE NEB LOCATED ON THE ERN EDGE OF A 30 TO 35     KT LOW-LEVEL JET. THE STORMS ARE BEING SUPPORTED BY THE LOW-LEVEL     JET ALONG WITH LIFT ASSOCIATED WITH A SHORTWAVE TROUGH EVIDENT ON     WATER VAPOR IMAGERY MOVE SEWD OUT OF THE CNTRL HIGH PLAINS. THIS     ALONG WITH INCREASING INSTABILITY SHOULD RESULT IN A GRADUAL     INCREASE IN STORM COVERAGE THROUGH EARLY AFTERNOON. FORECAST     SOUNDINGS IN SCNTRL NEB FROM 15Z TO 21Z INCREASE MUCAPE VALUES TO     ABOUT 1500 J/KG WITH THE INSTABILITY MOSTLY ABOVE 700 MB. THIS     SHOULD KEEP THE STORMS ELEVATED BUT MAY HELP INCREASE STORM     INTENSITY THIS AFTERNOON. THE INSTABILITY ALONG WITH 40 TO 45 KT OF     EFFECTIVE SHEAR AND STEEP MID-LEVEL LAPSE RATES OF 8.0 C/KM SHOULD     SUPPORT A THREAT FOR ISOLATED LARGE HAIL.          ..BROYLES/WEISS.. 05/30/2012               ATTN...WFO...OAX...TOP...GID...LBF...GLD...