Categorical Graphic
Probabilistic Tornado Graphic
Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Probabilistic Large Hail Graphic
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.

   SPC AC 161630
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1130 AM CDT THU AUG 16 2012
   
   VALID 161630Z - 171200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDWEST TO SRN
   PLAINS...
   
   ...MIDWEST TO SRN PLAINS...
   A STRONG COLD FRONT WILL CONTINUE TO PROGRESS STEADILY ACROSS LAKE
   MI INTO LOWER MI/NRN IL/NWRN IND THROUGH THE LATE AFTERNOON. THE
   TRAILING PORTION OF THIS WELL-DEFINED FRONT WILL MAKE SLOWER SEWD
   PROGRESS ACROSS CNTRL/SRN MO AND CNTRL OK THROUGH THE DAY AS THE
   BOUNDARY IN THESE AREAS WILL REMAIN WELL REMOVED FROM THE STRONGER
   LARGE SCALE UPPER TROUGH AND HEIGHT FALLS FORECAST TO SPREAD EAST
   ACROSS THE GREAT LAKES AND UPPER MIDWEST INTO EARLY FRI.
   
   DESPITE STRONGER FORCING AND SHEAR ACROSS THE NRN SEGMENT OF THE
   ADVANCING FRONT....FROM WI ACROSS MI/IL/IND...A STRONG PRE-FRONTAL
   SQUALL LINE /QLCS/ WAS MOVING FROM SWRN LOWER MI ACROSS IL/IND THIS
   MORNING. ADDITIONALLY...STRATIFORM RAIN REGION AND CONVECTIVE DEBRIS
   CLOUDINESS IN THE WAKE OF THIS PRE-FRONTAL QLCS WILL ACT TO INHIBIT
   AIRMASS RECOVERY AND STRONGER DESTABILIZATION COINCIDENT WITH FROPA
   LATER TODAY IN SOME OF THESE AREAS. MOST OPERATIONAL GUIDANCE DOES
   NOT SEEM TO DEPICT THE CURRENT CONVECTIVE SITUATION VERY WELL AND
   THIS INTRODUCES UNCERTAINTY IN TSTM EVOLUTION WITH THE FRONT LATER
   THIS AFTERNOON...ESPECIALLY OVER MI AND ADJACENT AREAS OF IND/NRN
   IL.
   
   AIRMASS AHEAD OF THE CURRENT SQUALL LINE...FROM ERN IND INTO OH IS
   UNDERGOING GRADUAL AND WEAK DESTABILIZATION WITH HEATING OF THE DAY.
   WHILE LINEAR CONVECTION IS BECOMING INCREASINGLY REMOVED FROM THE
   LARGER SCALE SUPPORT FOR UPWARD MOTION...IT SEEMS THAT LIFT ON THE
   LEADING EDGE OF THE COLD POOL COUPLED WITH SOME INCREASE IN
   DEEP-LAYER WLY FLOW ACROSS THESE AREAS COULD SUPPORT FAST-MOVING
   STORMS MOVING INTO STEEPENING LOW LEVEL LAPSE RATE ENVIRONMENT FOR A
   COUPLE MORE HOURS. OVERALL....HOWEVER...LACK OF STRONGER FORCING AND
   INSTABILITY SHOULD KEEP SEVERE POTENTIAL LIMITED WITH THIS LEADING
   LINE OF CONVECTION.
   
   STORM SCALE GUIDANCE INCLUDING THE HRRR AND WRF-ARW FROM NSSL APPEAR
   TO ACCURATELY DEPICT THE CURRENT SCENARIO AND INDICATE THAT THE
   FOCUS SHOULD SHIFT BACK TO THE COLD FRONT AND TRAILING PORTION OF
   THE QLCS OUTFLOW ACROSS IL AND IND LATER THIS AFTERNOON. A NARROW
   CORRIDOR OF GREATER DESTABILIZATION SHOULD OCCUR NEAR THE FRONT TO
   SUPPORT MORE VIGOROUS DEVELOPMENT WHERE MID LEVEL WLY FLOW IS
   FORECAST TO INCREASE TO AT LEAST 50KT THROUGH THE EVENING. THIS
   SHOULD CONTRIBUTE TO ORGANIZED STORMS/LINE SEGMENTS WITH DAMAGING
   WIND AND HAIL POTENTIAL THROUGH THE EVENING FROM CNTRL/SRN IL EWD
   ACROSS PARTS OF IND AND PERHAPS INTO THE LOWER OH VALLEY.
   
   FROM MO SWWD TO AR/OK...AIRMASS HAS ALREADY BECOME STRONGLY UNSTABLE
   WITH MLCAPE OVER 2000 J/KG INDICATED ALONG THE FRONT IN MO. AS
   MENTIONED...SHEAR AND FORCING WILL DIMINISH WITH SWWD EXTENT ALONG
   AND AHEAD OF THE BOUNDARY IN THESE AREAS. IN ADDITION...SUBSTANTIAL
   INHIBITION WILL PROVE SOMEWHAT HOSTILE TO MORE WIDESPREAD CONVECTION
   ALONG THE FRONT UNTIL PERHAPS LATER TODAY AND TONIGHT. LATEST
   VISIBLE IMAGERY SUGGESTS THAT PRONOUNCED SURFACE HEATING WILL
   CONTINUE NEAR THE FRONT FROM NERN OK INTO MO. EXPECT THAT PERSISTENT
   CONVERGENCE IN CONCERT WITH BOUNDARY LAYER HEATING AND MIXING WILL
   PROVE SUFFICIENT IN SOME AREAS TO OVERCOME INHIBITION AND ALLOW AT
   LEAST SCATTERED TSTM DEVELOPMENT TO OCCUR. LACK OF SHEAR MAY BE
   SOMEWHAT OFFSET BY LINEAR FORCING ALONG THE FRONT AND MAGNITUDE OF
   INSTABILITY TO RESULT IN A FEW SEVERE STORMS/MULTICELLULAR CLUSTERS
   WITH HAIL AND HIGH WINDS OVER THESE AREAS INTO TONIGHT.
   
   ...TX TO NRN GULF COAST...
   VERY UNSTABLE AND WEAKLY CAPPED CONDITIONS ARE AGAIN DEVELOPING
   ACROSS THESE AREAS WHERE WEAK MID LEVEL FLOW BUT ABUNDANT MOISTURE
   AND PRECIPITATION LOADING WILL LEAD TO RANDOM/SCATTERED WET
   MICROBURST ACTIVITY AND PERHAPS SOME HAIL. ACTIVITY MAY BECOME
   BETTER FOCUSED WHERE INLAND PENETRATING SEA/GULF BREEZES INTERSECT
   WITH A RESIDUAL FRONTAL ZONE ACROSS THE REGION.
   
   ..CARBIN/LEITMAN.. 08/16/2012
   
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