Apr 3, 2012 1300 UTC Day 1 Convective Outlook
Updated: Tue Apr 3 13:03:28 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20120403 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20120403 1300 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
20120403 1300 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
20120403 1300 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 031300
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0800 AM CDT TUE APR 03 2012
   
   VALID 031300Z - 041200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SRN
   PLNS...WRN OZARKS...AND LWR MS VLY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MID MS AND
   LWR OH VLYS...
   
   ...SYNOPSIS...
   NM UPR LOW EXPECTED TO MOVE ONLY SLOWLY E THIS PERIOD AS SYSTEM
   REMAINS WELL REMOVED FROM MAIN BELT OF THE AMPLIFIED WLYS EXTENDING
   ACROSS THE PACIFIC NW...CENTRAL CANADA...AND THE UPR GRT LKS-NERN
   U.S.  VORT LOBE ASSOCIATED WITH THE NM LOW...NOW EXTENDING SWD
   THROUGH ERN NM...SHOULD PIVOT ENE ACROSS W TX LATER THIS MORNING AND
   THEN TURN NE ACROSS WRN N TX AND WRN OK THIS AFTN.
   
   FARTHER NE...SATELLITE AND VWP DATA SUGGEST THAT DISTURBANCE IN PART
   RESPONSIBLE FOR LARGE MCS OVER E TX...AR...AND LA YESTERDAY NOW
   EXTENDS IN AN ARC FROM SW MO THROUGH NE AR TO CSTL MS.  THIS FEATURE
   SHOULD CONTINUE ENE THROUGH THE DAY...REACHING A CNTRL IL...MIDDLE
   TN...FL PANHANDLE LINE BY EVE.  
   
   AT LWR LVLS...QSTNRY SFC LOW THAT HAD BEEN PRESENT OVER THE TX
   PANHANDLE HAS PARTLY FILLED AS A RESULT OF /1/ SWD MOVEMENT OF POLAR
   AIR FROM KS-NEB...AND /2/ WIDESPREAD OUTFLOW FROM CONVECTION OVER
   THE SRN PLNS-LWR MS VLY.  AN ELONGATED LOW LVL CIRCULATION
   WILL...NEVERTHELESS...LIKELY PERSIST TODAY OVER NW TX...NEAR
   INTERSECTION OF THE POLAR COLD FRONT WITH MERGED DRY LINE-PACIFIC
   COLD FRONT.  THIS CIRCULATION OR WEAK LOW SHOULD DRIFT NE TOWARD THE
   OK-KS BORDER BY EVE...AHEAD OF AFOREMENTIONED NM VORT LOBE.
   
   FARTHER NE...RESIDUAL TRIPLE POINT LOW NOW IN SE IA SHOULD EDGE ESE
   INTO IL-IND LATER TODAY AS THE APPROACH OF A SHORTWAVE IMPULSE IN
   THE NRN STREAM /OVER THE UPR GRT LKS/ ENHANCES WSWLY LOW LVL FLOW
   OVER THE OH VLY.  THIS WILL ALLOW EXISTING STNRY FRONT EXTENDING E
   FROM THE LOW TO ADVANCE ENEWD AS WARM FRONT INTO PARTS OF
   IND...OH...AND KY. 
   
   THE VORT LOBE AND ASSOCIATED FRONT/DRYLINE OVER THE SRN PLNS...AND
   THE LOW/WARM FRONT OVER THE OH VLY...WILL BE THE MAIN FOCI FOR
   STRONG TO SVR TSTMS TODAY INTO TNGT.
   
   ...SRN PLNS INTO LWR MS VLY TODAY THROUGH TNGT...
   SCTD TO NUMEROUS TSTMS AND STORM CLUSTERS ARE EXPECTED THROUGH THE
   PERIOD OVER ERN PORTIONS OF THE SRN PLNS AND ADJACENT PARTS OF THE
   WRN OZARKS/LWR MS VLY AS VORT LOBE ROTATING NNE AROUND ERN SIDE OF
   NM UPR LOW...AND SUBSEQUENT WEAKER DISTURBANCES...ENHANCE ASCENT
   ACROSS REGION.
   
   GIVEN THAT OVERNIGHT MCSS HAVE SOMEWHAT STABILIZED REGION N OF THE
   RED RIVER...THE STRONGEST DIURNALLY DRIVEN DEVELOPMENT IS EXPECTED
   OVER CNTRL AND N TX.  COMBINATION OF INCREASING ASCENT IN
   MODERATELY-SHEARED...RICHLY MOIST LOW LVL ENVIRONMENT BENEATH
   DEEP/PERSISTENT EML SHOULD YIELD STORMS CAPABLE OF VERY LARGE HAIL
   AND LOCALLY DMGG WIND.  WIND PROFILES WILL REMAIN DIFFICULT TO
   GENERALIZE OVER SPACE AND TIME...AND EXPECTED FAIRLY WIDESPREAD 
   COVERAGE LIMITS PREDICTABILITY OF PREDOMINANT CONVECTIVE MODE/STORM
   TYPE.  BUT SETUP APPEARS AT LEAST CONDITIONALLY SUPPORTIVE OF A FEW
   SUPERCELLS ALSO CAPABLE OF TORNADOES GIVEN QUALITY OF MOISTURE
   INFLOW/DEGREE OF BUOYANCY.  THE STORMS LIKELY WILL MERGE INTO ONE OR
   MORE MCSS THIS EVENING.  ONE OF THESE COULD BECOME RATHER LARGE AND
   MOVE/DEVELOP E/SE TOWARD THE HOUSTON/BEAUMONT AREA TOWARD WED
   MORNING...WITH A CONTINUING RISK FOR SVR WEATHER.  A MORE
   LIMITED...THOUGH NON-ZERO...RISK FOR SVR STORMS WILL EXIST IN MUCH
   OF OK THROUGH EARLY TNGT...WHERE LARGE SCALE FORCING FOR ASCENT WILL
   BE GREATER...BUT SFC-BASED INSTABILITY MORE LIMITED THAN IN TX.
   
    ...MID MS/LWR OH VLYS...
   STRONG SFC HEATING WILL OCCUR TODAY IN WEAKLY SHEARED ENVIRONMENT
   ALONG AND S OF WARM/STNRY FRONT IN THE MID MS/LWR OH VLYS.  AREA
   SOUNDINGS SHOW PRESENCE OF A DEEP EML ATOP A RELATIVELY MODEST MOIST
   SFC LAYER.  COMBINATION OF HEATING WITH WEAK LOW LVL CONFLUENCE AND
   ASCENT AHEAD OF MID/UPR LVL VORT LOBE SHOULD SUPPORT DEVELOPMENT OF
   CLUSTERS/SHORT BANDS OF WEAKLY ORGANIZED AFTN/EVE STORMS.  THESE MAY
   YIELD SVR HAIL AND LOCALLY DMGG WIND AS THE WARM SECTOR EXPANDS
   FARTHER E INTO IND AND WRN OH.  THE STORMS LIKELY WILL MERGE INTO A
   FAIRLY EXTENSIVE...S TO SE-MOVING MCS OVER PARTS OF IL/IND/KY LATER
   TNGT.  THIS SYSTEM MAY FEATURE BOTH FORWARD-PROPAGATING
   SEGMENTS/SMALL BOWS...AND BACK-BUILDING/WWD-DEVELOPING
   ACTIVITY...WITH A DIMINISHING THREAT FOR LOCALLY SVR WIND AND HAIL. 
   
   ...WRN/CNTRL KS LATER TODAY INTO TNGT...
   ELEVATED TSTMS WILL BE POSSIBLE LATER TODAY/TNGT IN WRN/CNTRL KS AS 
   LEADING EDGE OF DCVA/ASCENT IMMEDIATELY AHEAD OF NM UPR LOW/ VORT
   LOBE APPROACHES REGION.  STEEP MID LVL LAPSE RATES COULD YIELD 
   MARGINALLY SVR HAIL. 
   
   ...SERN U.S. THIS AFTN...
   A LOW PROBABILISTIC RISK FOR SVR HAIL/LOCALLY DMGG WIND WILL EXIST
   OVER A LARGE PART OF THE SERN U.S...WHERE RELATIVELY STEEP MID LVL
   LAPSE RATES WILL RESIDE ATOP A FAIRLY MOIST/WEAKLY CONFLUENT
   BOUNDARY LAYER.  THE GREATEST CONCENTRATION OF SUCH ACTIVITY MAY
   OCCUR OVER N FL AND ADJACENT PORTIONS OF GA...WHERE ASCENT WILL BE
   ENHANCED BY APPARENT MCV/WEAK VORT MAX ON SRN END OF AFOREMENTIONED
   UPR IMPULSE.  ALTHOUGH THIS REGION IS SOMEWHAT DRIER THAN AREA
   AFFECTED BY SIMILAR WIND PROFILES/LARGE SCALE ASCENT YESTERDAY OVER
   LA...AR...AND MS...STRONG SFC HEATING/STEEPENING LOW LVL LAPSE RATES
   MAY COMPENSATE FOR ENHANCED ENTRAINMENT TO YIELD STRONG SFC WIND
   GUSTS.
   
   ..CORFIDI/COHEN.. 04/03/2012
   
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