Apr 15, 2013 0600 UTC Day 1 Convective Outlook
Updated: Mon Apr 15 06:04:36 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20130415 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20130415 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
20130415 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
20130415 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.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 74,488 6,374,334 Tulsa, OK...St. Louis, MO...Springfield, MO...Broken Arrow, OK...Ft. Smith, AR...
   SPC AC 150600
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0100 AM CDT MON APR 15 2013
   
   VALID 151200Z - 161200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS EASTERN/SOUTHERN OK TO
   OZARKS/LOWER OH VALLEY...
   
   ...SYNOPSIS...
   THE LARGE SCALE PATTERN WILL UNDERGO AMPLIFICATION THROUGH THE
   PERIOD. AN UPPER TROUGH CURRENTLY OVER THE UPPER MIDWEST WILL
   ADVANCE NORTHEASTWARD TOWARD NORTHERN ONTARIO...ALL WHILE A STRONG
   POLAR JET/UPPER TROUGH DIGS SOUTHEASTWARD OVER THE GREAT
   BASIN/CENTRAL ROCKIES. A SLOW MOVING FRONTAL BOUNDARY FROM NORTH
   TX/SOUTHERN OK NORTHEASTWARD TO THE OZARKS/MIDDLE MS VALLEY WILL BE
   THE PRIMARY FOCUS FOR TSTMS...INCLUDING SOME SEVERE. 
   
   ...NORTH TX AND SOUTHERN/EASTERN OK TO OZARKS/LOWER OH VALLEY...
   THE COLD FRONT ACROSS THE MIDDLE MS VALLEY/MIDWEST WILL DECELERATE
   EARLY TODAY...GENERALLY STALLING IN A SOUTHWEST-NORTHEAST FASHION
   LATER TODAY FROM NORTH TX AND SOUTHERN/EASTERN OK INTO CENTRAL IL.
   COINCIDENT WITH THE FRONTAL ZONE...RELATIVELY NEBULOUS BACKGROUND
   FORCING FOR ASCENT WILL EXIST ACROSS MUCH OF THE REGION IN
   ASSOCIATION WITH MODERATELY STRONG/BROAD SOUTHWESTERLY MID-HIGH
   LEVEL FLOW...AND BUILDING UPPER HEIGHTS/GRADUALLY WARMING
   TEMPERATURES ALOFT. THIS GENERAL SCENARIO PUTS INTO QUESTION THE
   EXTENT/LIKELIHOOD OF DEEP CONVECTION THROUGH PEAK HEATING...WITH
   CONVECTION MOST LIKELY TO OCCUR TONIGHT...LIKELY FOCUSED IMMEDIATELY
   NEAR OR PERHAPS JUST A BIT BEHIND /NORTH OF/ THE BOUNDARY ACROSS THE
   OZARKS INTO IL/INDIANA. 
   
   ACROSS NORTH-CENTRAL TX AND SOUTHERN/EASTERN OK...SUFFICIENT
   HEATING/CONVERGENCE COULD EXIST NEAR THE ANGLING SURFACE FRONT
   AND/OR WEAK SURFACE LOW/ADJACENT DRYLINE TO ALLOW FOR A FEW TSTMS TO
   DEVELOP LATE THIS AFTERNOON/EARLY EVENING. AMID LOWER 60S/PERHAPS
   SOME MIDDLE 60S F SURFACE DEWPOINTS...THE BOUNDARY LAYER IS LIKELY
   TO BECOME MODERATELY UNSTABLE /UP TO 2000-2500 J PER KG MLCAPE/ BY
   PEAK HEATING. IF/WHERE STORMS DEVELOP...AMPLE INSTABILITY/VEERING
   WIND PROFILES WOULD SUPPORT A FEW SUPERCELLS CAPABLE OF LARGE HAIL.
   ANY SUCH SEVERE THREAT SHOULD TEND TO WANE WITHIN AN HOUR OR TWO OF
   SUNSET...WITH TSTM DEVELOPMENT NOCTURNALLY BECOMING MORE PROBABLE
   FARTHER NORTHEAST INTO THE OZARKS/MIDWEST.
   
   AS MENTIONED...TSTMS WOULD APPEAR TO BE MORE PROBABLE /AND OF
   GREATER COVERAGE/ TONIGHT NEAR THE SURFACE FRONT ACROSS THE OZARKS
   INTO DOWNSTATE IL/INDIANA. SEVERE HAIL WOULD APPEAR TO THE PRIMARY
   CONCERN...BUT THE POSSIBILITY OF NEAR-SURFACE BASED TSTMS AND A
   RELATIVELY STRONG WIND FIELD ALSO SUGGESTIVE OF SOME DAMAGING WIND
   POTENTIAL. EVEN WHILE STEADY LOW LEVEL MOISTENING WILL BE OCCURRING
   COINCIDENT WITH A RELATIVELY STRONG/VEERED LOW LEVEL JET...THE
   NEAR-FRONTAL NATURE OF THE CONVECTION AND NOCTURNALLY INCREASING
   CINH IS CURRENTLY EXPECTED TO TEMPER TORNADO POTENTIAL.
   
   ...FL...
   WITHIN A RELATIVELY MOIST AIRMASS...AT LEAST ISOLATED/WIDELY
   SCATTERED TSTMS COULD REDEVELOP THIS AFTERNOON WITH AID OF SEA
   BREEZE CIRCULATIONS. AN ISOLATED DOWNBURST CANNOT BE ENTIRELY RULED
   OUT ACROSS INTERIOR SOUTH-CENTRAL FL PENINSULA...BUT THE OVERALL
   POTENTIAL CURRENTLY APPEAR MARGINAL WITH RESPECT TO SEVERE
   PROBABILITIES.
   
   ..GUYER/MOSIER.. 04/15/2013
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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