Categorical Graphic
Probabilistic Tornado 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
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
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 101955
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0255 PM CDT TUE MAY 10 2011
   
   VALID 102000Z - 111200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS INDIANA...OH VALLEY TO
   COASTAL CAROLINAS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS UPPER MS VALLEY
   REGION...
   
   --- UPDATES ---
   
   ...OH VALLEY/INDIANA TO CAROLINAS...
   REF SPC WWS 268-270 AND RELATED MESOSCALE DISCUSSIONS FOR LATEST
   NEAR-TERM GUIDANCE ON SVR THREAT WITH ONGOING AND INCIPIENT SVR
   TSTMS IN THESE REGIONS.  OUTLOOK LINES HAVE BEEN ADJUSTED
   ACCORDINGLY.
   
   ...CENTRAL OK TO CENTRAL TX...
   MRGL HAIL THREAT EXISTS WITH ELEVATED TSTMS MOVING NWD TO NNEWD
   ACROSS THIS REGION...AHEAD OF DRYLINE.  REF SPC MESOSCALE DISCUSSION
   710 FOR MORE DETAILS.  THREAT CLOSER TO DRYLINE STILL APPEARS RATHER
   CONDITIONAL.  THICK HIGH CLOUD COVER RELATED TO CONVECTIVE/PRECIP
   AREA FARTHER E COMBINED WITH LACK OF ROBUST CONVERGENCE HAVE BEEN
   LIMITING FACTORS.  HOWEVER...SFC MESOANALYSIS SHOWS SECONDARY
   PSEUDO-DRYLINE AND CONFLUENCE LINE FROM FST-INK...CORRESPONDING TO
   GRADIENT FROM TEENS TO 40S F SFC DEW POINTS.  LOCALLY ENHANCED LIFT
   ALONG THAT FEATURE MAY BE SUPPORTING HIGH-BASED/SHALLOW CONVECTION
   NOW EVIDENT IN THAT AREA...WHICH MAY BECOME SOURCE REGION FOR AT
   LEAST ISOLATED TSTM DEVELOPMENT NEXT FEW HOURS.
   
   ..EDWARDS.. 05/10/2011
   
   .PREV DISCUSSION... /ISSUED 1105 AM CDT TUE MAY 10 2011/
   
   ...SYNOPSIS...
   LARGE SCALE PATTERN HAS BECOME VERY AMPLIFIED AS THE WRN TROUGH
   SHIFTS SLOWLY E AND RIDGE E OF MS RIVER MOVES LITTLE THRU THE
   PERIOD. A VIGOROUS IMPULSE THAT EJECTED FROM THE TROUGH HAS WRAPPED
   UP AN UPPER LOW SERN MT WHICH WILL TRACK NEWD ACROSS ND INTO SRN
   MANITOBA WHILE SRN CLOSED UPPER LOW WRN AZ SHIFTS EWD ACROSS SRN
   ROCKIES OVERNIGHT.
   
   SURFACE LOW ERN SD WILL MOVE NWD INTO SRN MANITOBA WHILE TRAILING
   COLD FRONT NOW THRU ERN NEB SHIFTS SLOWLY EWD ACROSS MN INTO WRN IA
   WHILE SRN PORTION ACROSS SWRN KS MAKES LITTLE FURTHER PROGRESS AS
   UPPER FLOW BACKS AHEAD OF NEXT UPPER IMPULSE. THE WARM FRONT
   CURRENTLY FROM SRN MN/IA BORDER SEWD ACROSS OH VALLEY TO THE SRN NC
   COAST WILL SHIFT SLOWLY NE/EWD AND WITH STRONG DIABATIC HEATING
   BECOMING A FOCUS FOR ACTIVE THUNDERSTORMS.
   
   ...IND/OH TO CAROLINAS...
   
   REF MCD 709
   
   STEEP LOW TO MID LEVEL LAPSE RATES COUPLED WITH BOUNDARY LAYER DEW
   POINTS RISING THRU THE 60S WILL YIELD A MODERATELY TO STRONGLY
   UNSTABLE AIR MASS TODAY W/SW OF WARM FRONT WHERE MLCAPE VALUES WILL
   APPROACH 2000-3000+ J/KG.
   
   PRONOUNCED VEERING SHEAR PROFILES...40-50KT BRN SHEAR...VICINITY
   WARM FRONT IN THE AREA OF LOW LEVEL MOISTURE AND TEMP ADVECTION WILL
   LEAD TO INITIATION OF SURFACE BASED STORMS FROM CENTRAL IND/SWRN OH
   SEWD ACROSS APPALACHIANS TO THE COASTAL AREA OF SC/SRN NC THRU THE
   AFTERNOON.
   
   SUPERCELLS ARE LIKELY WITH THE INITIAL STORM DEVELOPMENT...EVOLVING
   INTO FORWARD-PROPAGATING MCSS BY LATER THIS AFTERNOON/EVENING
   PRODUCING LARGE HAIL AND DAMAGING WINDS. GIVEN THE SHEAR/CAPE
   PARAMETERS VERY LARGE HAIL CAN BE EXPECTED WITH ANY SUPERCELL.
   
   ..MN/WI...
   
   SURFACE LOW CURRENTLY OVER ERN SD IS FORECAST TO DEVELOP NWD  TODAY
   IN CONJUNCTION WITH THE STRONG VORTICITY MAXIMUM LIFTING NNEWD
   THROUGH THE WRN DAKOTAS.  AS THIS OCCURS...ASSOCIATED WARM FRONT
   ACROSS SRN MN WILL LIFT NWD...EXTENDING FROM THE RED RIVER VALLEY TO
   SRN WI BY LATE AFTERNOON/EARLY EVENING.  BOUNDARY LAYER DEWPOINTS TO
   NEAR 70F AND STEEP MIDLEVEL LAPSE RATES WILL CONTRIBUTE TO A
   STRONGLY UNSTABLE AIR MASS S OF WARM FRONT THIS AFTERNOON WHERE
   MLCAPE VALUES WILL INCREASE TO 2500-3500+ J/KG.
   
   WITH THE STRONG HEIGHT FALLS/FORCING FOR ASCENT ATTENDANT TO
   ABOVE-MENTIONED VORTICITY EXPECTED TO REMAIN WELL W OF THE REGION
   THROUGH THIS EVENING...SURFACE-BASED STORM INITIATION WILL LIKELY BE
   DELAYED UNTIL LATE AFTERNOON/EVENING DUE TO
   THE STRENGTH OF THE CAP.  THE MOST PROBABLE AREA OF STORM
   DEVELOPMENT WILL BE NRN/CNTRL MN LATE THIS AFTERNOON INTO EVENING
   INVOF WARM/COLD FRONT INTERSECTION.
   
   ONCE STORMS DEVELOP...THE COMBINATION OF THE STRONG INSTABILITY
   AND VERTICALLY VEERING WIND PROFILES WILL SUPPORT SUPERCELLS
   WITH A RISK FOR VERY LARGE HAIL...DAMAGING WINDS AND A
   FEW TORNADOES.  SUBSEQUENT UPSCALE GROWTH TO A SEWD-MOVING MCS WOULD
   BE POSSIBLE TONIGHT WITH A CONTINUED THREAT FOR HAIL AND DAMAGING
   WINDS INTO PARTS OF WI.
   
   ...SRN PLAINS...
   CURRENTLY A WEAK UPPER TROUGH NOTED ON W/V IMAGERY APPROACHING TX
   BIG BEND...HAS GENERATED BOTH WIDESPREAD MID CLOUDS ALONG WITH
   CONSIDERABLE ELEVATED CONVECTION OVER THE TX HILL COUNTRY.
   
   THIS ACTIVITY IS LIKELY TO REMAIN ELEVATED ABOVE THE CAP AND ROOTED
   WITHIN A STEEP LAPSE RATE ENVIRONMENT WITH 700-500 MB LAPSE RATES OF
   9.0-9.5 C/KM.  A LOW END HAIL THREAT WILL PERSIST INTO THE AFTERNOON
   GIVEN THE MID LEVEL INSTABILITY...HOWEVER THE TIMING OF THIS UPPER
   FEATURE WILL BE DISRUPTIVE ON ANY DRY LINE SEVERE THREAT FURTHER W
   LATER TODAY.
   
   ALONG WITH BACKING FLOW ALOFT AHEAD OF SWRN TROUGH AND RATHER WEAK
   LOW LEVEL CONVERGENCE ON THE DRY LINE...STILL DIFFICULT TO DELINEATE
   ANY AREA OF W TX/WRN OK THAT WOULD BE WORTHY OF AN UPGRADE TO A
   SLIGHT RISK.
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z