Oct 13, 2012 0600 UTC Day 1 Convective Outlook
Updated: Sat Oct 13 05:35:32 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20121013 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20121013 1200 UTC Day 1 Tornado Probabilities 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
20121013 1200 UTC Day 1 Damaging Wind Probabilities 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
20121013 1200 UTC Day 1 Large Hail Probabilities 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 130532
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1232 AM CDT SAT OCT 13 2012
   
   VALID 131200Z - 141200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN/CENTRAL PLAINS TO
   PORTIONS UPPER MS VALLEY REGION...
   
   ...SYNOPSIS...
   SPLIT-FLOW PATTERN NOW OVER WRN CONUS IS FCST TO DEAMPLIFY THROUGH
   PERIOD.  WELL-DEFINED MID-UPPER LEVEL CYCLONE -- INITIALLY OVER ERN
   UT/WRN CO REGION -- IS FCST TO MOVE ENEWD ACROSS CO BY START OF
   PERIOD...DEVOLVING TO OPEN-WAVE TROUGH AS IT CROSSES CENTRAL PLAINS.
    BY 14/00Z...EXPECT HIGH-AMPLITUDE SHORTWAVE TROUGH WITH SLGT
   POSITIVE TILT...FROM S-CENTRAL/SERN NEB ACROSS WRN KS...TX
   PANHANDLE...AND TX SOUTH-PLAINS REGION.  THIS PERTURBATION WILL
   BECOME MORE NEUTRALLY TILTED WITH TIME THEREAFTER...BUT ALSO...WILL
   LINK WITH NRN-STREAM FLOW BELT AND DEAMPLIFY.  TROUGH SHOULD BE
   CROSSING WRN OZARKS...WRN MO...AND IA BY 14/12Z.
   
   AT SFC...PAC COLD FRONT IS FCST TO MOVE EWD OUT OF ROCKIES...WITH
   ATTACHED FRONTAL-WAVE LOW OVER ERN NEB/WRN IA REGION BY 14/00Z...AND
   FRONT SWWD ACROSS N-CENTRAL KS...NWRN OK AND TRANS-PECOS AREA OF W
   TX.  BY LATE AFTERNOON...DRYLINE SHOULD INTERSECT PAC FRONT
   OBLIQUELY OVER NWRN OR WRN OK...AND EXTEND SSWWD ACROSS NW TX AND
   PERMIAN BASIN REGION.  DRYLINE AND PAC FRONT SHOULD MERGE THROUGH
   REMAINDER PERIOD.  MEANWHILE...DIFFUSE WARM FRONT -- NOW LOCATED
   OVER PORTIONS CENTRAL/SRN OK AND SRN AR -- IS FCST TO MOVE OR
   REDEVELOP NWD RAPIDLY ACROSS LOWER MO VALLEY REGION EARLY IN PERIOD.
    WARM FRONT SHOULD EXTEND FROM SFC LOW ACROSS NRN IA AND SRN WI BY
   14/00Z.  BY END OF PERIOD...EXPECT PRIMARY SFC LOW OVER NWRN IL/SWRN
   WI REGION...WITH WARM FRONT ENEWD OVER LOWER MI...AND COLD FRONT
   OVER NRN/WRN MO...ERN OK...AND W-CENTRAL TX.
   
   ...PORTIONS SRN/CENTRAL PLAINS...
   BAND OF TSTMS SHOULD BE ONGOING AT START OF PERIOD FROM PORTIONS
   W-CENTRAL TX NNEWD ACROSS NW TX AND WRN OK...INTO PORTIONS CENTRAL
   KS AND PERHAPS FARTHER NE.  RELATED ANVIL SHIELD WILL SUBDUE PACE OF
   INSOLATION IN ITS INFLOW REGION.  HOWEVER...COMBINATION OF SLOW SFC
   HEATING AND BOUNDARY-LAYER THETAE ADVECTION SHOULD YIELD FAVORABLY
   LARGE BUOYANCY TO SUPPORT GROWING SVR THREAT WITH TIME THROUGHOUT
   DAYLIGHT HOURS...AS BAND MOVES EWD ACROSS OUTLOOK AREA. 
   BACKBUILDING WITH TIME ALSO IS POSSIBLE ACROSS PORTIONS W-CENTRAL/SW
   TX ALONG/AHEAD OF DRYLINE...PERHAPS AS FAR S AS RIO GRANDE. 
   FURTHERMORE...SOME PROGS SUGGEST MID-LATE AFTERNOON QUASI-LINEAR
   TSTM DEVELOPMENT BEHIND INITIAL ACTIVITY AND ALONG/AHEAD OF COLD
   FRONT OVER PORTIONS KS/NWRN OK.  WIDTH AND MAGNITUDE OF ANY
   DESTABILIZATION CORRIDOR BEHIND INITIAL/PRIMARY TSTM BAND IS QUITE
   QUESTIONABLE ATTM...THOUGH THIS AREA GENERALLY IS COVERED BY
   UNCONDITIONAL...MRGL TO SLGT-RISK LEVEL PROBABILITIES THAT ALREADY
   ACCOUNT FOR EARLIER TSTMS. 
   
   PRIMARY THREAT FROM ANY OF THE ABOVE CONVECTION WILL BE DAMAGING
   GUSTS...WITH QUASI-LINEAR MODES DOMINANT FOR MOST OF PERIOD. 
   NONETHELESS...FAVORABLE DEEP SHEAR AND POTENTIAL FOR AT LEAST A FEW
   SUPERCELLS SUGGESTS CATEGORICAL HAIL RISK.  ANY SUCH
   SUPERCELLS...ALONG WITH EMBEDDED QLCS CIRCULATIONS...COLLECTIVELY
   OFFER RELATIVELY MAXIMIZED TORNADO POTENTIAL AT LEAST BETWEEN NW TX
   AND WRN MO...WHERE ENLARGED LOW-LEVEL HODOGRAPHS ARE MOST LIKELY TO
   JUXTAPOSE WITH FAVORABLE DESTABILIZATION.  TORNADO THREAT FARTHER NE
   AND SW...WHILE NONZERO...IS MORE CONDITIONAL.
   
   OVERALL SVR POTENTIAL SHOULD DIMINISH FROM LATE EVENING ONWARD OVER
   MOST OF THIS AREA AS BOUNDARY LAYER SLOWLY STABILIZES...AND AS
   PRIMARY MID-UPPER WAVE DEAMPLIFIES.  THREAT MAY PERSIST LONGEST
   OVERNIGHT ACROSS PORTIONS S TX INTO N-CENTRAL/NE TX AND SERN
   OK...WHERE LOW-LEVEL THETAE WILL REMAIN HIGHEST IN ABSENCE OF
   SUBSTANTIAL CAPPING.
   
   ...NRN MO/ERN NEB TO SWRN WI...NWRN IL...
   SCATTERED TSTMS MAY MOVE NEWD ACROSS THIS REGION EARLY IN
   PERIOD...PERHAPS AS EXTENSION OF ACTIVITY NOW CROSSING PORTIONS
   CENTRAL/SRN HIGH PLAINS.  SOME ACTIVITY MAY PERSIST OR REDEVELOP
   INTO AFTERNOON HOURS WHEN BOUNDARY-LAYER THETAE ADVECTION COULD
   INTRODUCE SFC-BASED PARCELS TO CONVECTIVE INFLOW REGION. 
   SEPARATE/NNE-SSW ALIGNED BELT OF TSTMS ALSO MAY DEVELOP AHEAD OF SFC
   COLD FRONT OVER PORTIONS MO/IA AND SHIFT EWD.
   
   AFTERNOON/EVENING WIND PROFILES WILL BE FAVORABLE FOR SVR OVER WARM
   SECTOR IN THIS REGION...ALBEIT EXHIBITING SOME BACKING WITH HEIGHT
   IN MIDLEVELS COMMON TO QUASI-LINEAR EVENTS.  FCST SOUNDINGS SUGGEST
   35-45 KT EFFECTIVE SHEAR...ALONG WITH ENHANCED LOW-LEVEL HODOGRAPHS
   INVOF WARM FRONT AND SFC LOW.  MOST PROGS ALSO INDICATE SOME DEGREE
   OF SUFFICIENT SFC-BASED DESTABILIZATION ACROSS THIS REGION...E.G.
   1000-1500 J/KG MLCAPE PREDICTED BY NAM.  HOWEVER...SUBSTANTIAL
   DESTABILIZATION MAY BE PRECLUDED BY PRECURSORY PRECIP AND CLOUD
   COVER MOVING INTO THIS REGION FROM UPSHEAR AREAS OF CENTRAL PLAINS
   DURING MORNING/EARLY AFTERNOON HOURS.  WHILE CORRIDOR OF RELATIVELY
   ENHANCED SVR WIND POTENTIAL YET MAY DEVELOP POLEWARD OF PRESENT 30%
   LINE...EXTENT/TIMING REMAINS TOO UNCERTAIN TO EXTEND THAT
   PROBABILITY FARTHER NNE ATTM.
   
   ..EDWARDS/ROGERS.. 10/13/2012
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z