ZCZC SPCSWOMCD ALL ACUS11 KWNS 281839 SPC MCD 281839 NEZ000-KSZ000-COZ000-282045- MESOSCALE DISCUSSION 0823 NWS STORM PREDICTION CENTER NORMAN OK 0139 PM CDT THU MAY 28 2015 AREAS AFFECTED...PORTIONS OF ERN CO...WRN KS...SWRN NEB CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 281839Z - 282045Z PROBABILITY OF WATCH ISSUANCE...60 PERCENT SUMMARY...THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE DISCUSSION AREA DURING THE AFTERNOON HOURS AND MOVE EAST WITH A RISK FOR DAMAGING WINDS AND LARGE HAIL. A WATCH IS POSSIBLE PRIOR TO 20Z. DISCUSSION...IN THE WAKE OF MORNING CLOUD COVER...SUBSTANTIAL CLEARING/WARMING HAS OCCURRED ACROSS THE DISCUSSION AREA AND RESULTED IN NOTABLE DESTABILIZATION WHEN COMBINED WITH UPPER 50S/LOWER 60S DEW POINTS OUT ACROSS THE PLAINS. A SFC TROUGH EXTENDED FROM THE NEB PANHANDLE SWD ACROSS ERN CO...AND VIS IMAGERY REVEALS SOME CU/CB DEVELOPMENT ACROSS THE NEB PANHANDLE AND ERN CO. MESOANALYSIS AT 18Z REVEALS A CORRIDOR OF MLCAPE AVERAGING 1000 J/KG OVER SWRN NEB TO AROUND 2000 J/KG OVER SERN CO. WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH MOVING SEWD OVER ERN ID/WRN WY...WITH A LEAD IMPULSE MOVING THROUGH CENTRAL CO ATTM PROVIDING LARGE-SCALE FORCING FOR ASCENT. MODESTLY STRENGTHENING WIND FIELDS WILL RESULT IN 30-40 KTS OF WLY DEEP-LAYER SHEAR ACROSS THE AREA AND SUPPORT A MIX OF STORM MODES INCLUDING SUPERCELLS...WITH A TRANSITION TO LINEAR MODE LIKELY WITH TIME. STEEP MID-LEVEL LAPSE RATES WILL SUPPORT A LARGE HAIL THREAT WITH THE STRONGEST STORMS...WITH DAMAGING WINDS ALSO LIKELY. WHILE THE OVERALL TORNADO RISK SHOULD BE TEMPERED BY WEAK LOW-LEVEL WINDS...AT LEAST SOME POTENTIAL WILL EXIST WITH ROTATING STORMS...ESPECIALLY NEAR THE SFC TROUGH. AN INCREASE IN TSTM DEVELOPMENT IS ANTICIPATED ALONG/E OF THE FRONT RANGE...AND IN THE VICINITY OF THE SFC TROUGH/CONFLUENCE LINE OVER THE NEXT FEW HOURS...AND A WW IS PSBL. ..BUNTING/GOSS.. 05/28/2015 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LBF...DDC...GLD...PUB...BOU...CYS... LAT...LON 37040198 37390360 39670385 40290383 41010348 41550288 41890159 41820091 41140045 39720037 37720065 37040198 NNNN