SPC AC 130552

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1252 AM CDT SAT JUL 13 2013

   VALID 141200Z - 151200Z

   ...NO SVR TSTM AREAS FORECAST...

   ...SYNOPSIS...
   LARGE SCALE UPPER PATTERN OVER THE NRN US WILL CHANGE LITTLE DURING
   THE PERIOD AS BAND OF STRONGER WESTERLY WINDS IS FORECAST TO EXTEND
   FROM THE PACIFIC NW AND MT ENEWD ACROSS ONTARIO AND QUEBEC.  A
   STRONG RIDGE IS FORECAST TO REMAIN ANCHORED ACROSS THE LOWER GREAT
   LAKES/MIDDLE ATLANTIC REGION.  OVER THE SOUTH CENTRAL STATES...AN
   UPPER LOW IS FORECAST TO MOVE WWD ACROSS THE SRN PLAINS.

   AT THE SURFACE...A WEAKENING FRONT IS EXPECTED TO EXTEND FROM NWRN
   MN SWWD ACROSS ERN SD INTO WEST CENTRAL NEB AND NRN CO.

   ...CENTRAL/NRN HIGH PLAINS INTO NRN MN...
   A MOIST UNSTABLE ENVIRONMENT WILL CONTINUE NEAR THE AFOREMENTIONED
   FRONT WITH WEAK LOW LEVEL ELY WINDS OVER THE HIGH PLAINS WEST OF THE
   BOUNDARY.  THUNDERSTORMS ARE EXPECTED TO INCREASE NEAR THE FRONT AND
   IN THE UPSLOPE REGION DURING THE AFTERNOON AS DIABATIC HEATING
   RESULTS IN FURTHER DESTABILIZATION /MLCAPE REACHING 1000-1500 J PER
   KG/ WHILE CONTRIBUTING TO A DECREASE IN CIN.  HOWEVER...STRONGER
   WINDS ALOFT AND ASSOCIATED VERTICAL SHEAR WILL BE DISPLACED
   NORTHWEST OF THE STRONGER INSTABILITY AXIS.  ALTHOUGH AN ISOLATED
   SUPERCELL OR TWO MAY DEVELOP...WEAK DYNAMIC FORCING AND LIMITED
   VERTICAL SHEAR APPEAR MORE SUPPORTIVE OF A FEW STRONG MULTICELL
   STORMS DURING THE AFTERNOON AND EVENING.  THERE WILL BE POTENTIAL
   FOR ISOLATED HAIL AND STRONG WIND GUSTS WITH STRONGER CELLS...BUT
   OVERALL SEVERE THREAT SHOULD BE LIMITED IN THIS REGION.

   ...SRN PLAINS...
   COLD CORE NATURE OF THE UPPER LOW /500 MB TEMPERATURE OF -12C/
   MOVING WWD ACROSS OK/NRN TX IS FORECAST CONTINUE THROUGH SUNDAY. 
   MODEL GUIDANCE DEVELOPS SUBSTANTIAL AREAS OF PRECIPITATION
   ACCOMPANYING THE LOW WITH RESULTANT FORECAST SOUNDINGS EXHIBITING
   CONVECTIVE STORM MODIFICATION SIGNATURES /SATURATED MID LEVELS AND
   WEAK LAPSE RATES/ AND LIMITED OVERALL INSTABILITY.  THERE IS
   POTENTIAL FOR LOCAL AREAS TO UNDERGO STRONGER DIABATIC HEATING AND
   DESTABILIZATION WHERE BREAKS IN CLOUDS DEVELOP...AND A FEW STRONGER
   STORMS CAPABLE OF PRODUCING HAIL OR GUSTY SURFACE WINDS MAY FORM IN
   THESE AREAS DURING THE AFTERNOON AND EVENING.

   ...TN VALLEY...
   MODEL GUIDANCE INDICATES STRONGER DEEP LAYER SELY WINDS WILL OCCUR
   IN THE WAKE OF THE SRN PLAINS UPPER LOW.  SCATTERED TO NUMEROUS
   STORMS ARE EXPECTED TO DEVELOP WITHIN A MINIMALLY CAPPED UNSTABLE
   ENVIRONMENT DURING THE DAY.  WEAK LAPSE RATES WITHIN A MOIST AIR
   MASS /PW OF 1.75-2.O IN/ ARE EXPECTED TO LIMIT THE OVERALL MAGNITUDE
   OF INSTABILITY AND UPDRAFT INTENSITY ACROSS THE REGION...BUT
   MODERATE VERTICAL SHEAR OF 20-30 KT IN THE LOWEST 6 KM WILL PROMOTE
   A FEW ORGANIZED MULTICELL CLUSTERS THAT WILL SPREAD TOWARD THE NW. 
   PRECIPITATION LOADING EFFECTS MAY YIELD A FEW WET MICROBURSTS DURING
   THE AFTERNOON AND EVENING.

   ..WEISS.. 07/13/2013

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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z