ZCZC SPCSWOMCD ALL ACUS11 KWNS 050157 SPC MCD 050157 NEZ000-SDZ000-KSZ000-COZ000-050330- MESOSCALE DISCUSSION 1638 NWS STORM PREDICTION CENTER NORMAN OK 0857 PM CDT SUN SEP 04 2016 AREAS AFFECTED...PORTIONS OF SWRN/S-CENTRAL SD...WRN NEB...NWRN KS...EXTREME NERN CO CONCERNING...SEVERE THUNDERSTORM WATCH 465... VALID 050157Z - 050330Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 465 CONTINUES. SUMMARY...DAMAGING WINDS WILL BE THE PRIMARY THREAT WITH LINES/CLUSTERS OF SEVERE STORMS THROUGH 04Z...WITH ISOLATED LARGE HAIL ALSO POSSIBLE. A RELATIVELY LOCALIZED THREAT FOR A TORNADO EXISTS WITH ISOLATED STORMS ACROSS WESTERN/CENTRAL NEBRASKA FOR THE NEXT COUPLE OF HOURS...WHERE THE SEVERE THUNDERSTORM WATCH WAS RECENTLY EXTENDED EAST. DISCUSSION...SEVERAL SEVERE THUNDERSTORMS WERE IN PROGRESS IN ACROSS WW 465 AT 0155Z...INCLUDING AN INCREASINGLY ORGANIZED LINEAR SYSTEM ACROSS THE SD/NORTHERN NEB PORTION OF THE WW...CLUSTERS OF SEVERE STORMS OVER NORTHWEST KS...AND MORE ISOLATED SEVERE STORMS OVER WESTERN/CENTRAL NEB. LATEST MESOANALYSIS AND 00Z UPPER AIR DATA SHOW MODERATE-LOCALLY STRONG INSTABILITY /MAXIMIZED OVER CENTRAL NEB/ ACROSS THE REMAINING VALID PORTIONS OF WW 465 ALONG WITH 40-55 KTS OF EFFECTIVE SHEAR. LINEAR/CLUSTER MODES HAVE BECOME MORE PREDOMINANT ACROSS MUCH OF THE WW AREA AS MERGING COLD POOLS AND INCREASING LARGE-SCALE ASCENT PROMOTE UPSCALE GROWTH...AND A BOOKEND VORTEX HAS BECOME ESTABLISHED SOUTHEAST OF PHILIP SD WHERE SEVERAL REPORTS OF SEVERE WINDS HAVE BEEN RECEIVED. SEVERE STORMS ACROSS NORTHERN PORTIONS OF THE WW AREA WILL SOON MOVE INTO SOUTHERN PORTIONS OF WW 466 WITH A MORE CONCENTRATED DAMAGING-WIND THREAT THROUGH LATE EVENING. STORMS OVER NORTHWEST KS CONTINUE TO TRANSITION INTO A MORE LINEAR MODE...THOUGH EMBEDDED STRONGER UPDRAFTS SUGGESTS ISOLATED LARGE HAIL REMAINS POSSIBLE IN THIS AREA FOR A FEW MORE HOURS. MORE ISOLATED SUPERCELLS HAVE DEVELOPED OVER PORTIONS OF CENTRAL NEB DURING THE PAST 1-2 HOURS. ALTHOUGH AT LEAST SOME TORNADO RISK REMAINS FOR THE NEXT 1-2 HOURS...INCREASING CINH WITH TIME WILL RESULT IN DIMINISHED TORNADO POTENTIAL. REFER TO MCD 1637 FOR DETAILS IN THIS AREA. SOME SEVERE THREAT WILL LIKELY CONTINUE BEYOND 04Z...AND TRENDS WILL CONTINUE TO BE MONITORED FOR THE NEED FOR A NEW WATCH...OR A TEMPORAL/AREAL EXTENSION OF THE EXISTING WATCH...AS THE SCHEDULED EXPIRATION OF WW 465 APPROACHES. ..BUNTING.. 09/05/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ABR...GID...LBF...DDC...UNR...GLD...BOU... LAT...LON 38950018 38390135 38670201 39830212 40810230 41240229 41860218 42450185 43150183 43640178 43840151 43850098 43680045 43469996 43179977 41820017 38950018 NNNN