SPC MD 678

MD 0678 CONCERNING TORNADO WATCH 170… FOR PARTS OF NERN CO / WRN-SWRN NE / PORTIONS OF WRN KS


MESOSCALE DISCUSSION 0678
NWS STORM PREDICTION CENTER NORMAN OK
0515 PM CDT SAT MAY 18 2013

AREAS AFFECTED...PARTS OF NERN CO / WRN-SWRN NE / PORTIONS OF WRN KS

CONCERNING...TORNADO WATCH 170...

VALID 182215Z - 182315Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 170 CONTINUES.

SUMMARY...A LARGE TO VERY LARGE HAIL THREAT WILL PREDOMINATE OVER
THE NEXT 1-2 HOURS FROM WRN NE S AND SEWD INTO PORTIONS OF WRN KS.
THE TORNADO THREAT WILL SEEMINGLY INCREASE AROUND 00Z AND
THEREAFTER.

DISCUSSION...SUBJECTIVE SURFACE MESOANALYSIS PLACES A DRYLINE FROM
THE NE PANHANDLE AND ARCING SEWD TO A DRYLINE BULGE OVER SWRN KS
NEAR DDC.  FAIRLY SUBSTANTIAL BOUNDARY LAYER MIXING ALONG AND IN
AREAS ADJACENTLY E OF THE DRYLINE OVER WRN KS INTO WRN NEB FEATURES
DEWPOINTS IN THE UPPER 50S TO LOWER 60S --CONTRIBUTING TO SIZABLE
SURFACE TEMP/DEWPOINT SPREADS 20-30 DEG F.  UNTIL THESE SPREADS AND
LCL/S BEGIN TO DECREASE EARLY THIS EVENING AND LOW LEVEL SHEAR
STRENGTHENS...LARGE TO VERY LARGE HAIL AND ISOLD DMGG WINDS WILL BE
THE MAIN THREATS.

AS OF 2215Z...WDSS-II SHOWS THE MOST INTENSE SUPERCELLS OVER
NESS/TREGO COUNTIES IN KS.  AS THIS SUPERCELL CLUSTER SLOWLY MOVES
TO THE N...VERY LARGE HAIL WILL LIKELY IMPACT THIS IMMEDIATE
VICINITY OVER THE NEXT HOUR OR TWO.

..SMITH.. 05/18/2013

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GID...LBF...DDC...GLD...BOU...CYS...

LAT...LON   37109963 38370021 39280262 40240346 42660320 42240080
            40330221 39199944 37449915 37109963

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md0678.html