Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 202232
SWOMCD
SPC MCD 202232
MNZ000-210000-

MESOSCALE DISCUSSION 1415
NWS STORM PREDICTION CENTER NORMAN OK
0532 PM CDT SUN JUL 20 2014

AREAS AFFECTED...NW AND N CENTRAL MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 202232Z - 210000Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ISOLATED SEVERE TSTM DEVELOPMENT POSSIBLE NEXT 1-2 HOURS
ALONG A PRE-FRONTAL TROUGH ACROSS NW MN...WITH SOME RISK FOR LARGE
HAIL/DAMAGING WINDS.  STORM COVERAGE/LONGEVITY IS SOMEWHAT IN
QUESTION...AS IS THE NEED FOR A SEVERE THUNDERSTORM WATCH.

DISCUSSION...VISIBLE SATELLITE/RADAR IMAGERY SHOW THE EARLY SIGNS OF
TSTM DEVELOPMENT ALONG A PRE-FRONTAL TROUGH IN NW MN...WHERE STRONG
SURFACE HEATING AND WEAK LOW-LEVEL ASCENT HAVE WEAKENED CONVECTIVE
INHIBITION.  BUOYANCY IS STRONG IN ADVANCE OF THE SURFACE TROUGH
/MLCAPE OF 2500-4000 J PER KG/...WHILE DEEP-LAYER VERTICAL SHEAR IS
SUFFICIENT FOR SUPERCELLS /EFFECTIVE BULK WIND DIFFERENCES AROUND 35
KT/.  A TENDENCY FOR WEAK HEIGHT RISES ALOFT AND A LACK OF
LARGER-SCALE FORCING FOR ASCENT CAST SOME DOUBT ON STORM COVERAGE
THIS EVENING ACROSS NW/N CENTRAL MN...BUT THE STORM ENVIRONMENT WILL
SUPPORT A RISK FOR ISOLATED LARGE HAIL/DAMAGING WINDS WITH ANY
SUSTAINED STORMS.  THUS...WILL CONTINUE TO MONITOR THIS AREA FOR
SIGNS FOR INCREASED STORM DEVELOPMENT/COVERAGE...WHICH MAY WARRANT
CONSIDERATION FOR A SEVERE THUNDERSTORM WATCH.

..THOMPSON.. 07/20/2014

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

ATTN...WFO...DLH...FGF...

LAT...LON   47649586 48349550 48609554 48809599 49069584 49189539
            49229474 48759423 48609373 48579375 47909394 47599430
            47399446 47129495 46929536 46819577 46879627 47099648
            47259621 47649586



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