Mar 31, 2012 1300 UTC Day 1 Convective Outlook
Updated: Sat Mar 31 13:04:27 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20120331 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20120331 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
20120331 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
20120331 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 311301
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0801 AM CDT SAT MAR 31 2012
   
   VALID 311300Z - 011200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF LWR MS VLYS/MID
   SOUTH AND ADJACENT AREAS...
   
   ...SYNOPSIS...
   PATTERN WILL CONTINUE TO AMPLIFY OVER THE LWR 48 THIS PERIOD AS
   STRONG E PACIFIC TROUGH CONTINUES E INTO WRN PORTIONS OF THE GRT
   BASIN BY 12Z SUN...AND DOWNSTREAM RIDGE BUILDS ACROSS THE
   RCKYS/PLNS.  FARTHER E...SERIES OF WEAKER DISTURBANCES COMPRISING
   THE BROAD...LOOSELY ORGANIZED TROUGH OVER THE S CNTRL AND ERN U.S.
   WILL CONTINUE TO PROGRESS GENERALLY E/SEWD. 
   
   AT LWR LVLS...STRONG SFC LOW ASSOCIATED WITH E PACIFIC TROUGH
   EXPECTED TO REACH THE ORE CST THIS EVE.  THE LOW SHOULD WEAKEN TNGT
   AS DOWNSTREAM LEE CYCLONE CONSOLIDATES AND DEEPENS OVER THE NRN HI
   PLNS.  ELSEWHERE...ERN PART OF WEAK FRONT NOW EXTENDING FROM THE MID
   ATLANTIC STATES WSW THROUGH THE LWR TN VLY INTO SRN MO...ERN
   NEB...AND THE DAKOTAS SHOULD ADVANCE SLOWLY SWD AS A COLD
   FRONT...WHILE THE WRN PORTION REFORMS NEWD WARM FRONT TNGT/EARLY
   SUN.
   
   THE ABOVE MENTIONED FRONT AND RELATED UPR DISTURBANCES WILL SERVE TO
   FOCUS TSTM DEVELOPMENT /SOME POTENTIALLY SVR/ OVER PARTS OF THE
   SOUTHEAST AND THE CNTRL U.S. TODAY AND TNGT.  A CONDITIONAL RISK FOR
   STRONG TO POSSIBLY SVR STORMS ALSO WILL EXIST OVER PARTS OF THE WEST
   IN CONJUNCTION WITH APPROACHING UPR TROUGH.  
   
   ...MID-SOUTH AND SOUTHEAST...
   MCV NOW NEAR MOB EXPECTED TO CONTINUE STEADILY ENEWD
   TODAY...ENHANCING ASCENT/UPR DIVERGENCE ACROSS N FL...SRN/CNTRL GA
   AND SRN SC.  LOW TO MID LVL LAPSE RATES IN THIS REGION WILL REMAIN
   MODEST.  BUT COMBINATION OF SFC HEATING WITH RELATIVELY RICH MOIST
   INFLOW AND 30+ KT UNIDIRECTIONAL WSWLY LWR TROPOSPHERIC FLOW MAY
   YIELD CLUSTERS/SHORT LINES OF STORMS POSING A RISK FOR LOCALLY DMGG
   WIND.
   
   FARTHER W AND N...AN IMPULSE MOVING SE ACROSS THE LWR OH VLY WITHIN
   LARGER SCALE UPR TROUGH WILL REACH THE CNTRL/SRN APPALACHIANS BY
   LATE AFTN.  ASCENT WITH THIS FEATURE...AND LEFT-EXIT REGION ASCENT
   FROM AN UPSTREAM JET STREAK OVER THE N CNTRL STATES...SHOULD FOSTER
   SCTD DIURNAL TSTMS OVER PARTS OF THE LWR MS/LWR TN VLYS.  OTHER
   STORMS MAY FORM LATE THIS AFTN ALONG COLD FRONT OVER THE CAROLINA
   PIEDMONT.
   
   MODERATE MID LVL WNW FLOW AND RESIDUAL EML MAY PROVE FAVORABLE FOR
   HAIL...ESPECIALLY OVER THE MID-SOUTH.  AND...ALTHOUGH DEEP SHEAR
   LIKELY WILL BE MARGINAL FOR SUPERCELLS...THE DEGREE OF INSTABILITY
   SUGGESTS A CONDITIONAL POTENTIAL FOR ISOLD LARGE HAIL AND LOCALLY
   DMGG WIND...ESPECIALLY IN WRN PART OF SLGT RISK AREA.
   
   ...NRN GRT BASIN/RCKYS LATE AFTN/EVE...
   FORCING FOR ASCENT WILL STRENGTHEN OVER REGION TODAY AS MID LVL
   HEIGHT FALLS INCREASE AHEAD OF E PACIFIC TROUGH.  GIVEN FAVORABLE
   TIMING RELATIVE TO DIURNAL HEATING...SETUP SHOULD  FOSTER
   DEVELOPMENT OF SCTD SHOWERS/ISOLD TSTMS BY LATE IN THE DAY. 
   ALTHOUGH BUOYANCY WILL REMAIN QUITE LIMITED /MLCAPE AOB
   250 J/KG/...STEEP LOW-LEVEL LAPSE RATES AND STRENGTHENING 
   DEEP SHEAR MAY RESULT IN STRONG TO LOCALLY SVR WIND GUSTS.
   
   ...LWR RIO GRANDE VLY LATE AFTN/EVE..
   THE MID LVL WLY FLOW SHOULD CONTINUE TO DIMINISH OVER REGION
   RELATIVE TO RECENT DAYS AS HEIGHTS BEGIN TO RISE OVER THE SRN PLNS. 
   NEVERTHELESS...SOME POTENTIAL WILL PERSIST FOR
   TSTMS FORMING OVER THE HIGHER TERRAIN OF NE MEXICO TO REACH THE RIO
   GRANDE LATER TODAY.  GIVEN SUBSTANTIAL LOW LVL VEERING
   PROFILES...AVAILABLE MOISTURE...AND STEEP LOW LVL LAPSE RATES...A
   LOW CONDITIONAL RISK FOR SVR WIND/HAIL WILL REMAIN THROUGH EARLY
   TNGT.
   
   ...PACIFIC NW THIS AFTN/EVE...
   STRENGTHENING WIND FIELDS AND MID LVL COOLING WILL OVERSPREAD THE 
   N PACIFIC CST AS STRONG UPR SYSTEM APPROACHES REGION.  LEAD
   SHORTWAVE IMPULSE SHOULD CONTINUE NNE OFF THE WA CST THROUGH
   MIDDAY...WHILE VORT NOW NEAR 40N/130 W SWEEPS ENE INTO WRN ORE/NW CA
   BY EVE.  SUFFICIENT LWR TROPOSPHERIC BUOYANCY SHOULD DEVELOP TO
   SUPPORT BANDS OF LOW-TOPPED STORMS.  GIVEN STRENGTH OF WIND FIELD
   AND COLD MID LVL TEMPS...THIS ACTIVITY COULD YIELD A FEW INSTANCES
   OF HAIL...AND POSSIBLY LOCALLY DMGG WIND AND/OR A TORNADO OR TWO
   THROUGH EARLY TNGT.
   
   ..CORFIDI/COHEN.. 03/31/2012
   
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