Categorical Graphic
Probabilistic Graphic
Probability of severe weather within 25 miles of a point. Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.

   SPC AC 150728
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0228 AM CDT SAT SEP 15 2012
   
   VALID 171200Z - 181200Z
   
   ...SYNOPSIS...
   UPPER-AIR PATTERN AMPLIFICATION DESCRIBED IN DAY-2 OUTLOOK WILL
   CONTINUE THIS PERIOD...AS STG SHORTWAVE TROUGH CONTINUES TO AMPLIFY
   AND SHIFT SEWD ACROSS NRN PLAINS AND UPPER MIDWEST.  BY END OF
   PERIOD...FULL-LATITUDE SYNOPTIC TROUGH WILL BE IN PLACE FROM HUDSON
   BAY ACROSS LS AND DOWN MS VALLEY TO LA.  RELATED SFC CYCLONE SHOULD
   DEEPEN AS IT MOVES EWD FROM ERN LS REGION ACROSS NECK OF ONT. 
   ATTACHED/STG SFC COLD FRONT SHOULD SWEEP EWD/SEWD OVER CENTRAL
   PLAINS AND UPPER MS VALLEY EARLY IN PERIOD...REACHING WRN LOWER
   MI...MO OZARKS...SRN OK AND SERN NM BY 18/00Z.  BY 18/12Z...FRONT
   SHOULD PROCEED TO SRN ONT...OH...AL AND NWRN GULF. 
   
   SRN-STREAM SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL
   IMAGERY OVER SRN NM -- WILL DEAMPLIFY AMIDST HEIGHT FALLS IMPINGING
   FROM NRN STREAM.  MODELS DIFFER SLIGHTLY ON LOCATION OVER E TX...AND
   MORE SUBSTANTIALLY ON AMPLITUDE OF THIS FEATURE...AT START OF
   PERIOD.  THIS LEADS TO MAJOR DIFFERENCES IN STRENGTH OF RESULTANT
   SFC LOW MOVING INLAND FROM GULF...DURING FIRST HALF OF
   PERIOD...ACROSS PORTIONS MS/AL AND PERHAPS GA.  
   
   ...LM AREA TO OZARKS...
   ISOLATED TO WIDELY SCATTERED TSTMS MAY DEVELOP INVOF FRONT DURING
   AFTERNOON/EARLY EVENING...MAINLY FROM LM AREA SWWD TO SRN MO WHERE
   FRONT WILL IMPINGE ON RELATIVELY MAXIMIZED LOW-LEVEL MOISTURE. 
   HOWEVER...SVR POTENTIAL APPEARS TOO CONDITIONAL/MRGL FOR AOA 5%
   PROBABILITIES ATTM.  DURING DAYLIGHT HOURS...STRONGEST MIDLEVEL FLOW
   AND DEEP-LAYER SHEAR WILL REMAIN BEHIND SFC BOUNDARY.  GREATER
   DEEP-LAYER WINDS/SHEAR THEN MAY SPREAD OVER PREFRONTAL SECTOR AFTER
   DARK...OVER OH/ERN KY WHEN BUOYANCY IS MINIMAL.  DURING
   AFTERNOON/EVENING...WEAKER PREFRONTAL SFC FLOW IS EXPECTED WITH SWWD
   EXTENT FROM MS RIVER...LIMITING CONVERGENCE AND LEADING TO
   UNCERTAINTIES ON TSTM COVERAGE AS WELL.  
   
   ...MID-SOUTH/TN VALLEY REGION...
   SUSTAINED EPISODE OF AT LEAST WIDELY SCATTERED TSTMS IN CLUSTERS
   APPEARS MORE PROBABLE OVER THIS REGION...THOUGH CONSIDERABLE
   UNCERTAINTIES EXIST REGARDING 
   1. STRENGTH/LOCATION OF FOCI FOR CONVECTION AND
   2. DEGREE OF DIURNAL DESTABILIZATION/HEATING AMIDST LARGE AREAS OF
   CLOUDINESS AND EMBEDDED PRECIP.
   
   SVR POTENTIAL OVER THIS REGION ALSO APPEARS TOO CONDITIONAL FOR
   OUTLOOK THIS FAR IN ADVANCE.  WHERE SUFFICIENT SFC-BASED
   DESTABILIZATION CAN OCCUR...GREATEST INFLUENCE WILL BE ISALLOBARIC
   IMPACT ON LOW-LEVEL WIND FIELDS FROM SFC CYCLONE.  STRONGEST
   SFC-WAVE SCENARIO -- I.E. NAM -- YIELDS FCST LOW-LEVEL HODOGRAPHS
   SUITABLE FOR SUPERCELLS IN PORTIONS TN VALLEY/AL. 
   ATTM...UNCERTAINTIES ON BOTH LOCATION AND INTENSITY OF
   SHEAR/BUOYANCY OVERLAPS PRECLUDE SPECIFIC SVR PROBABILITY AREAS.
   
   ..EDWARDS.. 09/15/2012
   
   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z