MESOSCALE DISCUSSION 1684
   NWS STORM PREDICTION CENTER NORMAN OK
   1016 PM CDT THU JUL 21 2011
   
   AREAS AFFECTED...NRN KS...SRN NEB...NW MO...FAR SW IA
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 668...
   
   VALID 220316Z - 220445Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 668
   CONTINUES.
   
   THE SEVERE THREAT CURRENTLY LOCATED IN WW 668 WILL DEVELOP SLOWLY
   EWD INTO NE KS...SE NEB AND NW MO DURING THE OVERNIGHT PERIOD. THE
   STRONGER CELLS WILL LIKELY CONTAIN HAIL AND STRONG GUSTY WINDS.
   ISOLATED WIND DAMAGE WILL BE POSSIBLE AND A WW MAY BE NEEDED TO THE
   EAST OF WW 668.
   
   A CLUSTER OF STRONG THUNDERSTORMS IS CURRENTLY ONGOING IN NW KS
   ALONG THE WRN EDGE OF MODERATE TO STRONG INSTABILITY. THE
   INSTABILITY AXIS EXTENDS EWD INTO SE NEB...NE KS AND NW MO WHERE
   MLCAPE VALUES ARE ESTIMATED IN THE 3000 TO 4000 J/KG. THIS WILL
   CONTINUE SUPPORT THE DEVELOPING MCS ALONG WITH LARGE-SCALE ASCENT
   ASSOCIATED WITH A CNTRL HIGH PLAINS SHORTWAVE TROUGH EVIDENT ON
   WATER VAPOR IMAGERY AND RUC ANALYSIS. FORECAST SOUNDINGS ALONG THE
   INSTABILITY AXIS AT 03Z TO 06Z SHOW 0-6 KM SHEAR VALUES IN THE 30 TO
   40 KT RANGE. THIS MAY INCREASE AS THE LOW-LEVEL JET STRENGTHENS
   OVERNIGHT ENABLING A SEVERE THREAT TO CONTINUE WITH THE MCS AS THE
   STORMS MOVE INTO STRONG INSTABILITY. WIND DAMAGE WILL BE FAVORED
   WITH BOWING LINE-SEGMENTS AS THE MCS CONTINUES TO ORGANIZE.
   HOWEVER...MORE DISCRETE CELLS OUT AHEAD OF THE LEADING EDGE MAY
   CONTAIN A HAIL THREAT AS WELL.
   
   ..BROYLES.. 07/22/2011
   
   
   ATTN...WFO...EAX...OAX...TOP...ICT...GID...DDC...GLD...
   
   LAT...LON   40220009 39570091 38430022 38519808 38489648 38799427
               39249330 39729289 40399308 40409416 40639526 40869671
               40719817 40220009