MESOSCALE DISCUSSION 1454
NWS STORM PREDICTION CENTER NORMAN OK
0217 PM CDT THU JUL 12 2012
AREAS AFFECTED...ND...SD...MN
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 121917Z - 122045Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...PROSPECTS FOR AT LEAST ISOLATED TSTM DEVELOPMENT ARE
INCREASING NEAR A WEAK SURFACE LOW AND FRONTAL SYSTEM OVER ERN ND/SD
AND EXTREME WRN MN THIS AFTERNOON. A WATCH IS POSSIBLE AS STORMS
DEVELOP ACROSS THESE AREAS THROUGH THE AFTERNOON.
DISCUSSION...SURFACE ANALYSIS DEPICTED A WEAK 1010MB LOW CENTER 50
MI WNW OF GFK WITH A WIND SHIFT/COLD FRONT STRETCHING SSWWD INTO
NERN AND CNTRL SD AND A WARM FRONT EXTENDING DUE SOUTH ALONG THE WRN
MN BORDER. STRONG HEATING ACROSS THESE BOUNDARIES AND NEAR THE LOW
CENTER HAS CONTRIBUTED TO STRONG DESTABILIZATION WITH ESTIMATED
SBCAPE AOA 2000 J PER KG OVER MUCH OF THE REGION. VERY LITTLE
INHIBITION REMAINS BASED ON BIS MORNING SOUNDING ADJUSTED FOR
CURRENT CONDITIONS AND EXPECT TSTM INITIATION IS IMMINENT NEAR THE
LOW CENTER IN ND...AND WITHIN THE NEXT FEW HOURS ALONG THE COLD
FRONT INTO SD.
A BAND OF ENHANCED CYCLONIC MID LEVEL FLOW AROUND 30-40KT EXISTS
ACROSS THE ND/SD BORDER AREA WHICH SHOULD AID STORM SUSTENANCE IN
THIS AREA WITH THE CHANCE FOR HAIL AND WIND FROM STRONGER CELLS.
NEAR THE LOW CENTER EFFECTIVE SHEAR AND INSTABILITY ARE SOMEWHAT
WEAKER BUT LOW LEVEL VORTICITY AND CAPE COULD SUPPORT A FEW LOW
TOPPED ROTATING STORMS/SUPERCELLS. ENTIRE REGION APPEARS TO BE UNDER
THE INFLUENCE OF GENERALLY WEAK TO NEUTRAL LARGE SCALE ASCENT AS
MID/UPPER SHORT WAVE TROUGH TRANSLATES ACROSS THE AREA WITH LITTLE
IN THE WAY OF AMPLIFICATION/INTENSIFICATION FORECAST.
THUS...A FEW SEVERE STORMS APPEAR LIKELY BUT OVERALL STORM COVERAGE
REMAINS SOMEWHAT IN QUESTION. AREA WILL CONTINUE TO BE MONITORED FOR
CONVECTIVE EVOLUTION AND A WATCH IS POSSIBLE IF MORE WIDESPREAD
SEVERE STORM POTENTIAL BEGINS TO EVOLVE.
..CARBIN/WEISS.. 07/12/2012
ATTN...WFO...MPX...FGF...FSD...ABR...BIS...
LAT...LON 46669919 47249921 47939908 48519896 48859808 48779721
48149633 47579589 45819583 45199600 44709665 44489737
44229874 44099946 44600005 45659942 46049927 46669919
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