MESO: Mesoscale Discussion 1112

ACUS11 KWNS 101843
SWOMCD
SPC MCD 101842 COR
MNZ000-101930-

MESOSCALE DISCUSSION 1112
NWS STORM PREDICTION CENTER NORMAN OK
0142 PM CDT SUN JUN 10 2012

AREAS AFFECTED...PORTIONS OF WRN/NRN MN

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 101842Z - 101930Z

CORRECTED FOR GEOGRAPHIC REFERENCE IN TEXT

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...TSTMS SHOULD RAPIDLY DEVELOP WITHIN THE NEXT 1-2 HRS
ACROSS PORTIONS OF WRN/NRN MN. PRIMARY THREATS OF DMGG WINDS AND
LARGE HAIL ARE EXPECTED...AND A WW WILL LIKELY BE NEEDED BY AROUND
20Z.

DISCUSSION...18Z SFC ANALYSIS PLACES A SLOW-MOVING COLD FRONT FROM
10 SE FSD TO 40 N BJI...WITH A WEAK SFC LOW POSITIONED NEAR VVV. THE
WARM SECTOR AHEAD OF THE COLD FRONT IS CHARACTERIZED BY A HOT/MOIST
AIR MASS...WHERE MOSTLY CLEAR SKIES HAVE ALLOWED TEMPERATURES TO
HEAT INTO THE UPPER 80S TO LOWER 90S WITH DEW POINTS GENERALLY IN
THE MID 60S...YIELDING MLCAPE VALUES OF 500-1500 J/KG /PER MODIFIED
18Z MPX SOUNDING/. VISIBLE SATELLITE LOOP SHOWS EXTENSIVE CLOUD
COVER FROM IMMEDIATELY E AND ALONG THE COLD FRONT AND AREAS FARTHER
W. POST-FRONTAL ELEVATED CONVECTION HAS DEVELOPED WITHIN THE PAST HR
OVER PARTS OF SERN ND...AND IS LIKELY ASSOCIATED WITH LEADING EDGE
OF STRONGER FORCED ASCENT ACCOMPANYING AN UPSTREAM UPPER TROUGH.

PERSISTENT FRONTAL CONVERGENCE AND CONTINUED DIABATIC HEATING SHOULD
BE SUFFICIENT TO WEAKEN CINH WITHIN THE NEXT 1-2 HRS...AND ALONG
WITH INCREASING MIDLEVEL HEIGHT FALLS ASSOCIATED WITH THE
AFOREMENTIONED UPPER TROUGH...WILL RESULT IN CONVECTIVE INITIATION
ALONG/AHEAD OF THE COLD FRONT...PERHAPS ALONG THE ERN EDGE OF
CLOUDINESS OVER WRN AND N-CNTRL MN.

CONVECTIVE MODE MAY INITIALLY FAVOR DISCRETE STORMS OR SMALL
CLUSTERS...BUT GIVEN SIGNIFICANT MERIDIONAL DEEP-LAYER FLOW
COMPONENT...A TRANSITION TO A LINEAR MODE IS EXPECTED TO OCCUR
RATHER QUICKLY. THIS...ALONG WITH STRAIGHT LOW-LEVEL
HODOGRAPHS...SHOULD LIMIT THE TORNADO RISK. THE THREAT FOR DMGG WIND
WILL BE ENHANCED BY STEEP LOW-LEVEL LAPSE RATES OWING TO STRONG
BOUNDARY LAYER HEATING/MIXING...AND BACKGROUND 0-3 KM FLOW NEAR 30
KTS /PER MPX VWP/. ADDITIONALLY...A HAIL THREAT COULD ACCOMPANY THE
STRONGEST EMBEDDED CONVECTIVE CORES GIVEN SUFFICIENT BACKGROUND
EFFECTIVE SHEAR VALUES /20-30 KTS/ AND MODERATE INSTABILITY.

..ROGERS/MEAD.. 06/10/2012

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

ATTN...WFO...DLH...MPX...FGF...FSD...ABR...

LAT...LON 48509269 46069344 43909456 43829636 45579619 47309526
48729441 48509269

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