Categorical Graphic
Probabilistic Graphic
Probability of severe weather within 25 miles of a point. Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.

   SPC AC 240837
   
   DAY 3 CONVECTIVE OUTLOOK RESENT 1
   NWS STORM PREDICTION CENTER NORMAN OK
   0337 AM CDT SUN APR 24 2011
   
   VALID 261200Z - 271200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS A LARGE PORTION OF THE
   ERN U.S. FROM THE NORTHEAST SWWD INTO ERN TX/ERN OK...
   
   CORRECTED FOR SPC WEB PAGE
   
   ...SYNOPSIS...
   AS ONE FEATURE ALOFT EJECTS NEWD ACROSS THE OH VALLEY INTO THE GREAT
   LAKES AREA...A SECOND WILL DIG QUICKLY SEWD OUT OF THE ROCKIES AND
   INTO THE SRN PLAINS -- BOTH WITHIN THE LARGER-SCALE TROUGH WHICH
   WILL KEEP BROAD CYCLONIC FLOW IN PLACE ACROSS A LARGE PORTION OF THE
   U.S. THROUGH THE PERIOD.
   
   WHILE THE INITIAL SURFACE LOW LIFTS NEWD INTO THE GREAT LAKES AND
   WEAKENS...LEAVING BEHIND A TRAILING FROM THE OH VALLEY SWWD ACROSS
   THE MID MS VALLEY INTO TX...A SECOND FRONTAL LOW WILL DEVELOP -- AND
   QUICKLY DEEPEN -- AS IT SHIFTS ACROSS TX AND INTO AR LATE.  THIS
   DEVELOPING LOW WILL CONTRIBUTE TO A POTENTIALLY SUBSTANTIAL SEVERE
   WEATHER EVENT ACROSS THE ARKLATEX AND MID MS VALLEY REGION.
   
   ...ARKLATEX REGION INTO THE MID MS VALLEY AREA...
   COMPLEX -- BUT POTENTIALLY SIGNIFICANT -- SCENARIO APPEARS TO BE
   UNFOLDING ACROSS THIS REGION...AS PERSISTENT WARM ADVECTION INVOF A
   SURFACE WARM FRONT RESULTS IN A SLOW INCREASE IN STORM COVERAGE
   AHEAD OF A RAPIDLY-APPROACHING UPPER FEATURE DIGGING SEWD FROM THE
   ROCKIES INTO THE SRN PLAINS.  WHILE SEVERE POTENTIAL IS APPARENT
   ACROSS PORTIONS OF THE AREA -- PARTICULARLY INVOF THE WARM FRONT --
   THROUGH MUCH OF THE PERIOD...THREAT SHOULD RAMP UP RAPIDLY FROM W TO
   E BY LATE AFTERNOON ACROSS SERN OK/E TX...AND THEN INTO THE EVENING
   ACROSS THE ARKLATEX INTO NRN LA/AR AND EVENTUALLY THE MID MS VALLEY
   REGION.
   
   FLOW ALOFT IS FORECAST TO INCREASE AS THE UPPER SYSTEM
   APPROACHES...AND AS BACKING/INCREASING LOW LEVEL FLOW EVOLVES IN
   RESPONSE...SHEAR WILL BECOME HIGHLY-FAVORABLE FOR SUPERCELLS.  IN
   ADDITION...IT APPEARS THAT LOW-LEVEL SHEAR WILL BECOME QUITE
   FAVORABLE FOR LOW-LEVEL ROTATION -- AND THUS THE POSSIBILITY OF
   STRONG TORNADOES...ESPECIALLY OVERNIGHT FOCUSED ON AR AND VICINITY. 
   GIVEN THIS POTENTIAL...UPGRADE TO HIGHER CATEGORY RISK APPEARS
   LIKELY IN LATER FORECASTS.
   
   ...SRN APPALACHIANS WWD ACROSS THE TN VALLEY REGION...
   PERSISTENT CYCLONIC FLOW ALOFT -- AND THE PASSAGE OF SEVERAL
   WEAK/EMBEDDED FEATURES -- ATOP A MOIST BOUNDARY LAYER DESTABILIZING
   THROUGH THE AFTERNOON SHOULD RESULT IN WIDESPREAD THUNDERSTORM
   DEVELOPMENT ACROSS A LARGE PORTION OF THE SERN U.S. -- FROM VA AND
   THE CAROLINAS WWD INTO THE TN VALLEY AND SOUTHEAST.  WITH MODEST BUT
   SUFFICIENT FLOW ALOFT ACROSS A BROAD AREA...MULTICELL/LOCAL
   SUPERCELL ORGANIZATION CAN BE EXPECTED WITH STORMS ACROSS A LARGE
   PORTION OF THIS REGION.  DETAILS REMAIN UNCLEAR ATTM...BUT WILL
   INCLUDE A LARGE PORTION OF THIS REGION IN SLIGHT RISK FORECAST --
   MAINLY FOR DAMAGING WIND AND HAIL POTENTIAL...THOUGH AN ISOLATED
   TORNADO OR TWO IS ALSO POSSIBLE.
   
   ...LOWER GREAT LAKES/OH VALLEY REGION...
   AS A STRONG SHORT-WAVE TROUGH AND SURFACE WARM FRONT LIFT QUICKLY
   NEWD ACROSS THE REGION...EXPECT WIDESPREAD SHOWERS AND THUNDERSTORMS
   EARLY IN THE PERIOD...WHICH SHOULD CONTINUE/REDEVELOP THROUGH THE
   PERIOD.  NARROWING DOWN EXACT AREAS OF SEVERE WEATHER POTENTIAL
   REMAIN DIFFICULT AT THIS TIME WITH WIDESPREAD AREA OF AT LEAST
   MARGINAL INSTABILITY AND A BROAD AREA OF STRONG FLOW ALOFT/FAVORABLE
   SHEAR.  DETAILS SHOULD BECOME CLEARER IN LATER FORECASTS...BUT
   ATTM...WILL INCLUDE A LARGE PORTION OF THE LOWER GREAT LAKES REGION
   SWWD INTO THE OH VALLEY AREA...WHERE POTENTIAL FOR MULTIPLE EPISODES
   OF STRONG/OCCASIONALLY SEVERE STORMS APPEARS TO EXIST -- INCLUDING
   THREATS FOR HAIL...DAMAGING WINDS...AND A COUPLE OF TORNADOES.
   
   ..GOSS.. 04/24/2011
   
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   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z