MESOSCALE DISCUSSION 1458, AREAS AFFECTED...MN/NWRN IA CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

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MESOSCALE DISCUSSION 1458 NWS STORM PREDICTION CENTER NORMAN OK 0135 PM CDT FRI JUL 13 2012 AREAS AFFECTED...MN/NWRN IA CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 131835Z - 131930Z PROBABILITY OF WATCH ISSUANCE...40 PERCENT SUMMARY...CONVECTIVE COVERAGE IS EXPECTED TO INCREASE FROM NERN MN SWWD INTO NWRN IA. AS STORMS BECOME BETTER ORGANIZED THIS AFTERNOON...DMGG WINDS AND HAIL WILL BECOME INCREASINGLY POSSIBLE. DISCUSSION...INITIAL CONVECTIVE DEVELOPMENT APPEARS TO BE PRIMARILY FOCUSED ALONG A WIND SHIFT AXIS/MOISTURE GRADIENT FROM NEAR ORR MN SWWD TO NEAR BROOKINGS SD. THE STRONGEST CORE ATTM IS OVER LINCOLN COUNTY MN...WHICH APPEARS TO HAVE BREACHED REMAINING CONVECTIVE INHIBITION WITH LIGHTNING RECENTLY OCCURRING. AN ADDITIONAL WIND SHIFT AXIS IS APPARENT ACROSS NWRN IA...WHERE HI-RES ENSEMBLES ARE INDICATING CONVECTIVE INITIATION IS POSSIBLE WITHIN THE HOUR. MODEST FLOW ALOFT /35 KT AT 500 MB/ EXISTS IN A RELATIVELY NARROW CORRIDOR ACROSS CNTRL/WRN MN...WHERE ROBUST UPDRAFTS AND SUSTENANCE OF CONVECTION WILL BE POSSIBLE. ELSEWHERE...WEAKER WINDS ALOFT MAY HINDER GREATER ORGANIZATION...THOUGH SUFFICIENT SURFACE-BASED DESTABILIZATION AND FORCING FOR ASCENT WITH AN EWD PROGRESSING UPPER LOW SHOULD CONTINUE TO SUPPORT BRIEF DISCRETE CELLS AND MULTICELLULAR CLUSTERS CAPABLE OF DMGG WINDS AND HAIL. ..HURLBUT/CARBIN.. 07/13/2012