MESOSCALE DISCUSSION 0628
   NWS STORM PREDICTION CENTER NORMAN OK
   0943 PM CDT SUN MAY 09 2004
   
   AREAS AFFECTED...CNTRL...SRN...ERN NEB
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 177...
   
   VALID 100243Z - 100445Z
   
   CONTINUE REMAINING VALID PORTION OF WW.
   
   LARGE-SCALE FORCING ASSOCIATED WITH SHORT WAVE TROUGH MIGRATING OUT
   OF THE NORTH CENTRAL ROCKIES INTO SOUTH DAKOTA/NEBRASKA CONTINUES TO
   SUPPORT VIGOROUS CONVECTIVE DEVELOPMENT ACROSS A LARGE PART OF
   CENTRAL INTO NORTHEASTERN NEBRASKA.  ACTIVITY HAS GENERALLY BEEN
   FOCUSED ALONG LOW-LEVEL THERMAL RIDGE AND ASSOCIATED INSTABILITY
   AXIS...WHICH IS BEGINNING TO BECOME OVERTURNED.  EXCEPTION TO THIS
   APPEARS TO BE ACROSS THE IMPERIAL/MCCOOK AREAS...WHERE CAPPING
   ELEVATED MIXED LAYER WILL PERSIST.  ON EDGE OF CAP ACROSS SOUTH
   CENTRAL NEBRASKA...WHERE STEEP MID-LEVEL LAPSE RATES WILL CONTINUE
   TO SUPPORT CAPE OF 1000 TO 2000 J/KG...FORCING ON NOSE OF 40 TO 50
   KT SOUTHERLY LOW-LEVEL JET WILL MAINTAIN MOST INTENSE CONVECTION
   INTO THE OVERNIGHT HOURS.  STRONG GUSTY WINDS MAY ACCOMPANY LEADING
   EDGE OF OUTFLOW SURGING THROUGH THE GRAND ISLAND/KEARNEY AREAS
   DURING THE NEXT HOUR OR TWO...WITH ADDITIONAL COLD POOL DEVELOPMENT
   POSSIBLE THROUGH 06Z.
   
   ..KERR.. 05/10/2004
   
   
   ATTN...WFO...FSD...OAX...GID...LBF...
   
   41189943 41409835 41869787 42339732 42399685 41869660
   41089683 40489742 40149858 40129928 40369984 40840040