MESOSCALE DISCUSSION 0803
   NWS STORM PREDICTION CENTER NORMAN OK
   0913 PM CDT TUE MAY 06 2008
   
   AREAS AFFECTED...IA...ERN NEB
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 266...
   
   VALID 070213Z - 070315Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 266
   CONTINUES.
   
   QLCS/S STRETCHING FROM NERN IA TO S-CNTRL NEB SHOULD CONTINUE TO
   PROPAGATE E/SEWD GENERALLY OUTSIDE OF WW 266. A DAMAGING WIND AND
   MARGINAL SEVERE HAIL THREAT SHOULD BE MAINTAINED FOR AT LEAST A FEW
   HOURS. HOWEVER...THE PROPENSITY FOR WANING INSTABILITY SHOULD RESULT
   IN AN OVERALL DIMINISHING TREND TO THE SEVERE THREAT AND THE NEED
   FOR ADDITIONAL WW/S REMAINS UNCERTAIN ATTM.
   
   AS OF 0200Z...RADAR/SATELLITE IMAGERY DEPICTED SEVERAL QUASI-LINEAR
   CLUSTERS OF TSTMS WITH A HISTORY OF OCCASIONAL SEVERE WIND
   GUSTS/LARGE HAIL. OVERALL SCENARIO REMAINS MESSY GIVEN ONGOING
   CONVECTION ACROSS S-CNTRL NEB BECOMING MORE W-E ORIENTED AND THE
   LINE NEAR TQE OVERRIDING CONVECTIVE OUTFLOW FROM NERN/CNTRL IA MCS. 
   WITH THE LOSS OF DAYTIME HEATING AND SUB-STANDARD QUALITY OF
   DOWNSTREAM AIR MASS /PER 00Z TOP AND DVN RAOBS/...THE MAINTENANCE OF
   A SUSTAINED SEVERE THREAT APPEARS UNCERTAIN. STILL WITH STRONG
   DEEP-LAYER SHEAR AND ORGANIZED NATURE OF THE LINES...AT LEAST A
   LOCALIZED SEVERE THREAT WILL LIKELY PERSIST FOR THE REST OF THIS
   EVENING.
   
   ..GRAMS.. 05/07/2008
   
   
   ATTN...WFO...DVN...ARX...DMX...EAX...FSD...OAX...
   
   41309691 41789618 42789525 42749411 42859281 43439158
   43289087 42289054 41719094 41569238 41289391 40669505
   40009690 40829706