Apr 12, 2012 1630 UTC Day 1 Convective Outlook
Updated: Thu Apr 12 16:28:26 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20120412 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20120412 1630 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
20120412 1630 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
20120412 1630 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 121624
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1124 AM CDT THU APR 12 2012
   
   VALID 121630Z - 131200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CENTRAL
   AND SOUTHERN PLAINS STATES...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF NORTHERN/CENTRAL
   CA...
   
   ...PLAINS...
   A LARGE UPPER TROUGH WILL CONTINUE TO DIG OVER THE WESTERN STATES
   TODAY...WHILE A SHORTWAVE PERTURBATION OVER NM/CO EJECTS INTO THE
   CENTRAL PLAINS.  SOUTHERLY LOW LEVEL WINDS HAVE TRANSPORTED MID 50S
   SURFACE DEWPOINTS AS FAR NORTH AS NORTHWEST KS AND 60S INTO
   SOUTHWEST OK.  MOISTURE WILL CONTINUE TO INCREASE ALONG A NARROW
   CORRIDOR FROM WESTERN OK INTO WESTERN KS...WHERE THE PRIMARY CONCERN
   FOR SEVERE THUNDERSTORMS WILL OCCUR LATER TODAY.
   
   VISIBLE SATELLITE IMAGERY SHOWS THE LOW CLOUDS BURNING OFF ACROSS
   EASTERN CO/WESTERN KS...BUT PERSISTING OVER THE EASTERN TX PANHANDLE
   AND WESTERN OK.  THIS TREND INCREASES THE CONFIDENCE IN CONVECTIVE
   INITIATION OVER THE NORTHERN PORTIONS OF THE SLIGHT RISK AREA...BUT
   ADDS UNCERTAINTY FROM THE KS/OK BORDER SOUTHWARD.
   
   VIRTUALLY ALL MODEL SOLUTIONS HAVE CONVERGED ON THE DEVELOPMENT OF
   ISOLATED DISCRETE SUPERCELLS ALONG THE SURFACE DRYLINE THIS
   AFTERNOON FROM NORTHEAST CO INTO FAR WESTERN KS.  FORECAST SOUNDINGS
   APPEAR QUITE FAVORABLE FOR TORNADIC SUPERCELLS CAPABLE OF VERY LARGE
   HAIL AND DAMAGING WINDS.  HAVE ALSO ADDED SIGNIFICANT TORNADO
   PROBABILITIES ACROSS THIS REGION AS COMBINATION OF STEEP LOW LEVEL
   LAPSE RATES...STRONG LOW LEVEL VERTICAL SHEAR...AND DISCRETE MODE
   ENHANCE THE RISK OF STRONG TORNADOES GENERALLY BETWEEN 22-02Z.  THE
   MAIN CONCERN FOR UPGRADING TO MODERATE IS THE LIKELY WIDE SPACING OF
   STORMS AND LIMITED AREAL COVERAGE.  THIS WILL BE RE-EVALUATED AT
   20Z.
   
   FARTHER SOUTH...MODEL SOLUTIONS ARE IN CONSIDERABLE DISAGREEMENT ON
   WHETHER CONVECTION CAN FORM THIS EVENING SOUTH OF THE KS/OK BORDER. 
   THE 12Z GFS IS MOST BULLISH ON DEVELOPMENT.  THE CONDITIONAL RISK OF
   TORNADIC SUPERCELLS IS QUITE HIGH IN THIS AREA SO WILL MAINTAIN
   ONGOING ELEVATED PROBABILITIES.  HOWEVER...LIMITED DAYTIME HEATING
   AND WEAK CAPPING ARE SUFFICIENT TO CAST DOUBT ON INITIATION.
   
   ...CA...
   A VIGOROUS UPPER SYSTEM WILL MOVE ASHORE THIS EVENING OVER CENTRAL
   CA...WITH THE UPPER LOW CENTER ALONG THE COAST BY 00Z.  COLD
   TEMPERATURES ALOFT COUPLED WITH CONSIDERABLE SUNSHINE WILL YIELD A
   CORRIDOR OF 500-1000 J/KG CAPE VALUES OVER THE NORTHERN AND CENTRAL
   VALLEY OF CA.  LOW LEVEL WINDS ARE NOT PARTICULARLY STRONG
   TODAY...BUT FAVORABLE EFFECTIVE SHEAR VALUES ARE SUFFICIENT FOR
   LOW-TOPPED SUPERCELL STORMS CAPABLE OF HAIL.  OROGRAPHICALLY BACKED
   LOW LEVEL WINDS IN THE VALLEY COULD ALSO RESULT IN ONE OR TWO BRIEF
   TORNADOES THIS AFTERNOON.
   
   ..HART/HURLBUT.. 04/12/2012
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z