Dec 17, 2011 0830 UTC Day 3 Severe Thunderstorm Outlook
Updated: Sat Dec 17 07:56:07 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20111217 0830 UTC Day 3 Outlook Graphic
Probabilistic Graphic
20111217 0830 UTC Day Probabilitic 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 170753
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0153 AM CST SAT DEC 17 2011
   
   VALID 191200Z - 201200Z
   
   ...SYNOPSIS...
   
   CUTOFF UPPER LOW NOW SITUATED OVER NRN BAJA THAT IS PART OF A WRN
   U.S. REX BLOCK WILL BEGIN TO EJECT EWD SUNDAY AND CONTINUE THROUGH
   THE SRN PLAINS MONDAY. ATTENDANT SFC LOW WILL LIKELY MOVE ACROSS NRN
   TX OR OK WITH TRAILING PACIFIC FRONT ADVANCING THROUGH THE REMAINDER
   OF TX.
   
   ...CNTRL THROUGH ERN TX AND WRN LA...
   
   STRONG 50-60 KT SLY LLJ ASSOCIATED WITH THE EJECTING UPPER LOW WILL
   TRANSPORT PARTIALLY MODIFIED GULF AIR INTO THE SRN PLAINS MONDAY
   WITH SFC DEWPOINTS FROM THE LOW-MID 60S ACROSS SRN-SERN TX TO MID
   50S OVER N-NCNTRL TX. WRN EXTENSION OF SERN U.S. SFC RIDGE IS
   FORECAST TO BE IN PLACE EARLY MONDAY OVER CNTRL/ERN TX. INCREASING
   SLY FLOW AND ISENTROPIC ASCENT ABOVE THIS COOL...STABLE LAYER WILL
   LIKELY RESULT IN WIDESPREAD LOW CLOUDS EARLY IN PERIOD...LIMITING
   DESTABILIZATION POTENTIAL SOMEWHAT. NEVERTHELESS...LOW LEVEL THETA-E
   ADVECTION AND POTENTIAL FOR SOME OF THE LOW CLOUDS MIXING OUT FROM
   THE SOUTH DURING THE AFTERNOON MAY SUPPORT AN AXIS OF MARGINAL
   INSTABILITY WITH MLCAPE GENERALLY AOB 500 J/KG.
   
   A BAND OF STORMS WILL LIKELY BE IN PROGRESS WITHIN ZONE OF DEEPER
   ASCENT ALONG WARM CONVEYOR BELT ACROSS WRN TX MONDAY MORNING. SOME
   OF THE STORMS MAY INTENSIFY AND BECOME SURFACE BASED AS THEY BEGIN
   TO INTERACT WITH THE MOISTENING AND DESTABILIZING BOUNDARY LAYER
   FARTHER EAST. GIVEN DEGREE OF FORCING...PRIMARY CONVECTIVE MODE IS
   EXPECTED TO BE LINEAR. HOWEVER...ACTIVITY WILL REMAIN EMBEDDED
   WITHIN STRONG LOW-LEVEL AND DEEP SHEAR ACCOMPANYING THE SHORTWAVE
   TROUGH AS IT PROGRESSES EWD...SUPPORTING POTENTIAL FOR EMBEDDED
   ORGANIZED STRUCTURES. PRIMARY THREAT IS EXPECTED TO BE ISOLATED
   DAMAGING WIND...BUT A COUPLE OF TORNADOES CANNOT BE RULED OUT.
   THREAT WILL SHIFT INTO THE LOWER MS VALLEY OVERNIGHT. DUE TO
   POTENTIAL LIMITING FACTORS WITHIN THERMODYNAMIC ENVIRONMENT...5%
   PROBABILITIES WILL BE INTRODUCED AT THIS TIME...BUT A PORTION OF
   THIS AREA MAY NEED TO BE UPGRADED TO A SLIGHT RISK IN LATER
   OUTLOOKS.
   
   ..DIAL.. 12/17/2011
   
   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z