MESOSCALE DISCUSSION 1610
   NWS STORM PREDICTION CENTER NORMAN OK
   0746 PM CDT WED JUL 13 2011
   
   AREAS AFFECTED...SRN NEB/NRN KS
   
   CONCERNING...TORNADO WATCH 640...
   
   VALID 140046Z - 140115Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 640 CONTINUES.
   
   LOCAL WFO AREAL EXTENSION OF WW 640 IS POSSIBLE ACROSS NORTH CENTRAL
   KS AND SOUTH CENTRAL NEB.
   
   AT 00Z...SURFACE MESOANALYSES/STREAMLINE ANALYSIS SHOWED A BOUNDARY
   DRAPED ACROSS THE CENTRAL PLAINS...EXTENDING NWWD FROM SRN TO WEST
   CENTRAL MO THROUGH NERN KS INTO SOUTH CENTRAL NEB /INVOF FRANKLIN
   COUNTY/...WITH THIS BOUNDARY THEN EXTENDING SWWD TO WEST CENTRAL
   KS/EAST CENTRAL CO.  THE NWRN KS PORTION OF THIS BOUNDARY IS BEING
   AUGMENTED ESEWD BY AN ONGOING TSTM CLUSTER...CURRENTLY AFFECTING
   GRAHAM COUNTY.  MEANWHILE...A RECENT STRONG TSTM HAD FORMED ACROSS
   EAST CENTRAL NEB /MERRICK COUNTY/...WITH THIS STORM LOCATED NEAR AN
   INVERTED TROUGH WHICH EXTENDED ENEWD FROM FRANKLIN COUNTY NEB TO
   SWRN IA.
   
   WATER VAPOR IMAGERY SHOWED A COUPLE OF MIDLEVEL IMPULSES TRACKING
   ENEWD ACROSS CENTRAL/ERN NEB AND ACROSS NRN KS.  ASCENT WITH THESE
   IMPULSES WILL SUPPORT ADDITIONAL STRONG TO SEVERE TSTM DEVELOPMENT
   AS THESE FEATURES TRACK ACROSS THE CENTRAL PLAINS THIS EVENING...
   WHERE THE AIR MASS REMAINS MODERATELY UNSTABLE.  ENHANCED WSWLY
   MIDLEVEL WINDS /25-30 KT PER 00Z LBF SOUNDING/ ATOP GENERALLY ESELY
   LOW LEVEL WINDS IS RESULTING IN EFFECTIVE BULK SHEAR OF 35-40 KT. 
   GIVEN THE SUFFICIENT SHEAR/INSTABILITY VALUES...THE THREAT FOR
   ADDITIONAL SEVERE STORMS WILL CONTINUE AND LOCAL WFO AREAL EXTENSION
   OF WW 640 IS POSSIBLE ACROSS NORTH CENTRAL KS AND SOUTH CENTRAL NEB.
   
   ..PETERS.. 07/14/2011
   
   
   ATTN...WFO...ICT...GID...LBF...DDC...GLD...PUB...BOU...
   
   LAT...LON   39560465 39700342 40220135 40829874 41099785 40879739
               40129745 39999803 39239798 39169870 39120013 38720016
               38640103 38280116 38230208 38610210 38570320 38500406
               39100413 39160459 39560465