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 191956
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0256 PM CDT SAT MAY 19 2012
   
   VALID 192000Z - 201200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MO VALLEY REGION
   SSWWD INTO WRN OK/NWRN TX...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS A SMALL PORTION OF S
   FL...
   
   ...MID MO VALLEY REGION SSWWD INTO WRN OK/NWRN TX...
   FORECAST REMAINS ON TRACK...WITH INITIAL STORM DEVELOPMENT FORECAST
   INVOF THE SURFACE LOW NOW OVER CENTRAL KS...AHEAD OF WHICH THE
   WARM-SECTOR AIRMASS HAS BECOME MODERATELY UNSTABLE.  CONVECTION THUS
   FAR HAS REMAINED TO THE COOL SIDE OF THE FRONT...BUT EXPECT THE CAP
   TO CONTINUE TO WEAKEN OVER THE NEXT COUPLE OF HOURS FACILITATING
   WARM SECTOR INITIATION.
   
   GIVEN SHEAR SUPPORTIVE OF SUPERCELL STORMS...THREAT FOR LARGE HAIL
   AND DAMAGING WINDS CAN BE EXPECTED AS THE STORMS INTENSIFY -- AND
   EVENTUALLY DEVELOP SWD ACROSS OK.  THREAT FOR A TORNADO OR TWO
   SHOULD REMAIN GREATEST OVER S CENTRAL NEB/N CENTRAL KS NEAR THE
   SURFACE LOW /JUST AHEAD OF THE MAIN UPPER CIRCULATION
   CENTER/...WHERE MOST FAVORABLE LOW-LEVEL SHEAR SHOULD BE PRESENT.
   
   STORMS SHOULD CONTINUE OVERNIGHT...THOUGH A SLOW WANE IN SEVERE
   POTENTIAL IS EXPECTED WITH DIURNAL BOUNDARY LAYER STABILIZATION.
   
   ...S FL...
   SHOWERS AND THUNDERSTORMS ARE ONGOING ACROSS MAINLY THE SRN HALF OF
   FL THIS AFTERNOON...WITH STRONGEST STORM INITIATION OCCURRING IN
   CONJUNCTION WITH THE E COAST SEA-BREEZE BOUNDARY MOVING WWD WITH
   TIME.  WITH SUFFICIENT CAPE TO FUEL THE CONVECTION AND FAIRLY STRONG
   FLOW IN THE UPPER TROPOSPHERE...POTENTIAL FOR A FEW SEMI-ORGANIZED
   STORMS CAPABLE OF PRODUCING BRIEF DAMAGING GUSTS AND MARGINAL HAIL
   WILL CONTINUE FOR THE NEXT FEW HOURS.
   
   ..GOSS.. 05/19/2012
   
   .PREV DISCUSSION... /ISSUED 1117 AM CDT SAT MAY 19 2012/
   
   ...CENTRAL/SRN PLAINS...
   UPPER TROUGH OVER CO IS MOVING EWD TOWARD THE CENTRAL PLAINS AND
   MODEL GUIDANCE INDICATES THIS FEATURE WILL BEGIN TO LIFT ENEWD
   REACHING THE MIDDLE MO RIVER VALLEY LATER TONIGHT.  THE TROUGH IS
   ASSOCIATED WITH COLD MID LEVEL TEMPERATURES /-17C AT 500 MB/ WHICH
   WILL SPREAD EWD INTO THE PLAINS THIS AFTERNOON AND EVENING.  PRIMARY
   SURFACE COLD FRONT EXTENDS FROM NWRN MN SSWWD ACROSS CENTRAL
   NEB...WRN KS INTO THE NWRN TX PANHANDLE. THE FRONT WILL PROGRESS EWD
   REACHING ERN NEB/CENTRAL KS/NWRN OK LATE THIS AFTERNOON/EVENING AND
   PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT.
   
   ALTHOUGH STRONG SOUTHERLY LOW LEVEL WINDS ARE CONTINUING FROM THE
   SRN PLAINS INTO THE UPPER MS VALLEY...LOW LEVEL MOISTURE WILL BE
   SLOW TO INCREASE SUBSTANTIALLY OWING TO PERSISTENT ANTICYCLONIC
   TRAJECTORIES ACROSS THE WRN GULF OF MEXICO AND THE TX COAST.  THIS
   WILL LIMIT WARM SECTOR SURFACE DEW POINTS TO AROUND 60F OVER NEB AND
   KS.  HOWEVER...THE PRESENCE OF STEEP MID LEVEL LAPSE RATES
   ASSOCIATED WITH AN ELEVATED MIXED LAYER OVER THE PLAINS WILL ENHANCE
   POTENTIAL INSTABILITY WITH CAPE VALUES REACHING 1500-2000 J/KG LATER
   THIS AFTERNOON AND EVENING. THE EML IS ALSO EXPECTED TO INHIBIT
   DEVELOPMENT OF SURFACE-BASED STORMS UNTIL MID/LATE AFTERNOON ALONG
   THE FRONT WHEN DIABATIC HEATING AND FOCUSED UPWARD MOTION WEAKEN THE
   CAP SUFFICIENTLY FOR STORMS TO DEVELOP.  CONSENSUS OF TRADITIONAL
   AND CONVECTION-ALLOWING MODEL GUIDANCE PREDICTS CONVECTIVE
   INITIATION FROM SOUTH CENTRAL NEB ACROSS CENTRAL KS INTO NWRN OK
   DURING THE 21-23Z TIME FRAME.  
   
   AS THE UPPER TROUGH MOVES EWD...40-50 KT MID LEVEL SWLY FLOW WILL
   OVERSPREAD THE FRONTAL REGION PROVIDING SUFFICIENT DEEP LAYER SHEAR
   TO ENHANCE CONVECTIVE ORGANIZATION AND INTENSITY...INCLUDING
   SUPERCELL STRUCTURES.  THE STEEP LAPSE RATES WILL PROMOTE A THREAT
   FOR VERY LARGE HAIL WITH STRONGER CELLS...WHILE THE WELL MIXED
   BOUNDARY LAYER WILL ALSO FAVOR POTENTIAL FOR DAMAGING WIND GUSTS. 
   WITHIN SEVERAL HOURS AFTER INITIATION...THE STORMS ARE EXPECTED TO
   DEVELOP INTO ONE OR MORE CONVECTIVE BANDS/LINES WITH ACTIVITY THEN
   SPREADING EWD/NEWD WITH A GRADUAL TRANSITION INTO PRIMARILY A WIND
   DAMAGE THREAT WITH TIME.  ACTIVITY IS EXPECTED TO SLOWLY WEAKEN
   AFTER 03Z AS DIURNAL STABILIZATION OCCURS AFTER SUNSET. 
   
   ...SOUTH FL...
   THE SYNOPTIC PATTERN AND THERMODYNAMIC ENVIRONMENT APPEAR SIMILAR TO
   YESTERDAY WITH 12Z MFL SOUNDING SHOWING -10C AT 500 MB WITH
   RESULTANT STEEPER LAPSE RATES ENHANCING INSTABILITY.  ALTHOUGH LOW
   LEVEL WINDS BELOW 700 MB REMAIN WEAK...A STRONG SUBTROPICAL JET IS
   POSITIONED OVER SOUTH FL WITH 100 KT AT 200 MB.  STRONG HEATING
   NORTH OF THE CLOUD COVER OVER EXTREME SRN FL WILL PERMIT STORMS TO
   DEVELOP WITHIN THE WEAKLY CAPPED ENVIRONMENT DURING THE EARLY/MID
   AFTERNOON...WITH POTENTIAL FOR STRONGER CELLS TO PRODUCE LOCALIZED
   DAMAGING WET MICROBURSTS AND MARGINALLY SEVERE HAIL.
    
   ...TN VLY/N GA AREA...
   WRN EXTENSION OF LONG-LIVED...CAROLINAS UPPER TROUGH WILL MAINTAIN
   CORRIDOR OF COOL MID LVL TEMPS /AOB -14 C AT 500 MB/ ATOP
   STRONGLY-HEATED...RELATIVELY MOIST...VERY WEAKLY SHEARED ENVIRONMENT
   OVER PARTS OF TN AND THE WRN SLOPES OF THE SRN APPALACHIANS.  THIS
   SETUP MAY YIELD DIURNAL PULSE STORMS WITH ISOLATED WET MICROBURSTS
   AND/OR SVR HAIL.
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z