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000
ACUS11 KWNS 091759
SWOMCD
SPC MCD 091759
KSZ000-NEZ000-SDZ000-092000-

MESOSCALE DISCUSSION 1328
NWS STORM PREDICTION CENTER NORMAN OK
1259 PM CDT WED JUL 09 2014

AREAS AFFECTED...PORTIONS OF CENTRAL NEB...SOUTH CENTRAL SD AND
NORTH CENTRAL KS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 091759Z - 092000Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ELEVATED STORMS WILL CONTINUE TO DEVELOP DURING THE
EARLY-MID AFTERNOON FROM SOUTH-CENTRAL SD SSEWD THROUGH CENTRAL
NEB...WITH ISOLATED HAIL BEING THE PRIMARY THREAT.  A FEW HAILSTONES
COULD EXCEED 1-1.5 INCH IN DIAMETER...AS INDICATED BY RECENT WDSS-II
MESH DATA IN CHERRY COUNTY.  IF STORMS CAN BECOME SURFACE-BASED
TOWARD PEAK HEATING ACROSS SOUTH-CENTRAL NEB INTO NORTH-CENTRAL
KS...THEN AN ADDITIONAL THREAT FOR DAMAGING WINDS WOULD BE
POSSIBLE...AND WW ISSUANCE MAY BE NEEDED.

DISCUSSION...TIME LAPSE OF MOSAIC RADAR IMAGERY SHOWED TSTMS HAD
CONTINUED TO DEVELOP FOR THE LAST SEVERAL HOURS OVER SOUTH-CENTRAL
SD INTO PORTIONS OF NORTH-CENTRAL TO CENTRAL NEB.  THIS ACTIVITY IS
LOCATED WITHIN A ZONE OF WEAK LOW-LEVEL WAA AND DEEPER ASCENT
ATTENDANT TO A PROGRESSIVE MID-LEVEL IMPULSE...CURRENTLY MOVING SEWD
THROUGH WRN/CENTRAL NEB PER MOISTURE CHANNEL IMAGERY.  MODIFIED 12Z
LBF SOUNDING FOR SURFACE TEMP/DEWPOINT OF 82F/58F INDICATED A
REDUCTION IN MLCIN...THOUGH THE ENVIRONMENT REMAINS CAPPED
SUGGESTING THESE STORMS ARE ELEVATED.  OBJECTIVE ANALYSES SHOWED
THESE STORMS ARE TRACKING SSEWD ALONG THE ERN PORTION OF THE EML.
EFFECTIVE BULK SHEAR OF 40-50 KT IS FAVORABLE FOR SUPERCELLS AS
15-20 KT SLY LOW-LEVEL FLOW VEERS TO 35 KT AT 500 MB.  THESE FACTORS
SUPPORT A CONTINUED POTENTIAL FOR STRONGER CELLS TO PRODUCE
HAIL...SOME EXCEEDING 1-1.5 INCH.

GREATER CONCERN AND POTENTIAL NEED FOR A WATCH THIS AFTERNOON WILL
BE AS THESE STORMS DEVELOP FARTHER SSEWD INTO SRN NEB AND NRN KS.
THERE...STRONGER DIABATIC HEATING WILL RESULT IN A WELL-MIXED
BOUNDARY LAYER WITH FORECAST SOUNDINGS INDICATING STEEP SFC-3 KM
LAPSE RATES /AROUND 9.8 C PER KM/ AND LARGE SURFACE DEWPOINT
DEPRESSIONS AROUND 40 DEGREES F...ENHANCING THE THREAT FOR DAMAGING
WINDS.  FORCING FOR ASCENT WITH THE MIDLEVEL IMPULSE WILL SUPPORT
TSTM DEVELOPMENT WITH SSEWD EXTENT...SUCH THAT A WW MAY BE NEEDED.

..PETERS/EDWARDS.. 07/09/2014

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

ATTN...WFO...TOP...GID...LBF...UNR...GLD...

LAT...LON   39969760 39289812 39209907 39239971 39409997 39950014
            41790109 42650132 43130124 43430091 43229987 42629911
            41859851 40839794 39969760