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 032006
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0306 PM CDT SAT SEP 03 2011
   
   VALID 032000Z - 041200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SRN UPPER GREAT
   LAKES AND PORTIONS OF THE MIDWEST...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL GULF COASTAL
   REGION...
   
   ...SRN UPPER GREAT LAKES/MIDWEST...
   FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS CONTINUE FROM THE UPPER
   GREAT LAKES REGION SWWD INTO KS -- BOTH ALONG THE SURFACE FRONT
   CROSSING THE UPPER MS AND MID MO VALLEYS...AND IN THE WARM SECTOR
   ACROSS IA/IL AND VICINITY INVOF REMNANT CONVECTIVE OUTFLOW.
   
   WITH 65 KT MID-LEVEL JET SHIFTING SEWD ACROSS THIS REGION...SHEAR
   WILL CONTINUE TO SUPPORT ROTATING STORMS GIVEN DEGREE OF ONGOING
   DESTABILIZATION.  WHILE FORECAST FOR LOCALLY DAMAGING WINDS AND HAIL
   APPEARS ON TRACK...HAVE EXPANDED THE RISK AREA A BIT NWD INTO
   CENTRAL WI WHERE SOMEWHAT STRONGER DESTABILIZATION IS ONGOING AHEAD
   OF THE MAIN SURFACE FRONT THAN WAS PREVIOUSLY ANTICIPATED.
   
   ...CENTRAL GULF COAST...
   FORECAST ACROSS THIS AREA REMAINS ON TRACK...WITH T.S. LEE FORECAST
   TO SHIFT ONLY SLIGHTLY NWD ACROSS SRN LA THE REMAINDER OF THE
   PERIOD.  THIS WILL KEEP THE MOST FAVORABLE NERN QUADRANT OF THE
   STORM -- WHERE LOW-LEVEL VEERING/SHEAR IS MOST FAVORABLE -- FROM
   SERN LA EWD TO THE FL PANHANDLE.  THUS...WILL MAINTAIN ONGOING
   PROBABILITIES FOR TORNADO RISK ACROSS THIS REGION -- AS
   SMALL/TRANSIENT SUPERCELL STORMS EVOLVE WITHIN BANDING NE OF THE
   CENTER OF LEE.
   
   ..GOSS.. 09/03/2011
   
   .PREV DISCUSSION... /ISSUED 1123 AM CDT SAT SEP 03 2011/
   
   ...MIDWEST/CNTRL GRTLKS REGION...
   WATER VAPOR IMAGERY SHOWS TWO FEATURES OF INTEREST...A SYNOPTIC AND
   AMPLIFYING POSITIVE-TILT WAVE MOVING THROUGH MN AND A SUBTROPICAL
   DISTURBANCE ROTATING EWD THROUGH ERN NEB.  LATTER FEATURE WILL
   PROGRESS EWD TOWARD IA/NRN IL THROUGH THIS EVE WITH THE PRIMARY WAVE
   MOVING INTO THE UPR GRTLKS REGION.  IN THE LWR-LVLS...A COMPLEX
   ARRAY OF BOUNDARIES EXISTS FROM CNTRL LWR MI SWWD INTO SRN IA. 
   SYNOPTIC COLD FRONT...TIED TO THE MAIN UPR TROUGH...WAS BEGINNING TO
   ACCELERATE SEWD THROUGH CNTRL MN AND NWRN IA...TRAILING TO A WEAK
   LOW JUST W OF OMAHA.
   
   PRIMARY CORRIDOR OF ROBUST HEATING WILL OCCUR ALONG/S OF OUTFLOW
   BOUNDARIES FROM CNTRL/SRN LWR MI WSW THROUGH NRN IL AND EXTREME SERN
   IA/NRN MO.  HERE...MID-UPR 60S SFC DEW POINTS WILL COMBINE WITH 12Z
   OBSERVED MID-LVL LAPSE RATES OF 7-7.5 DEG C PER KM FOR MLCAPES
   2000-2500 J/KG.  COMPARATIVELY WEAKER DESTABILIZATION WILL OCCUR
   FARTHER N...AHEAD OF THE PRIMARY COLD FRONT...BUT... COOLER MID-LVL
   TEMPERATURES ASSOCIATED WITH THE PRIMARY TROUGH WILL COMPENSATE
   SOMEWHAT...ESPECIALLY IN AREAS WHERE CLOUDS THIN SUFFICIENTLY.
   
   SCATTERED TSTMS WILL LIKELY FESTER N OF THE OUTFLOW BOUNDARIES AND E
   OF THE COLD FRONT OVER PARTS OF NRN IA...SE MN AND MUCH OF WI WITH
   SPORADIC HAIL/GUSTY WINDS.  MORE ROBUST ACTIVITY WILL LIKELY EVOLVE
   IN THE HEAT CORRIDOR AND DOWNSTREAM OF THE NEB DISTURBANCE FROM
   SCNTRL/SERN IA INTO NRN/CNTRL IL THROUGH THE LATE AFTN. 
   HERE...MID-LVL WLY FLOW WILL GRADUALLY INCREASE ALONG SRN PERIPHERY
   OF THE AMPLIFYING TROUGH.  UNIDIRECTIONAL WLY FLOW
   REGIME...INCLUDING DEEP LAYER SHEAR MRGLLY SUPPORTIVE OF BRIEF
   SUPERCELLS...WILL ENCOURAGE BOWING LINE SEGMENTS WITH DMGG
   WINDS/HAIL THE PRIMARY THREATS. ACTIVITY WILL SPREAD DOWNSTREAM INTO
   PARTS OF CNTRL/SRN LWR MI THIS EVE WITH CONTINUED SVR WIND/HAIL.
   
   ...CNTRL GULF COASTAL REGION...
   TS LEE...CENTER VERY CLOSE TO SCNTRL LA...WILL DRIFT SLOWLY N OR NE
   THIS AFTN/TONIGHT.  MARITIME TROPICAL LOW-LEVEL BOUNDARY LAYER WILL
   EDGE AS FAR NWD AS SRN PARTS OF MS/AL WHILE DRY MID-LVL AIR WRAPS
   INTO THE SYSTEM FROM THE W/SW.  THIS WILL RESULT IN PERIODIC HEATING
   BETWEEN SPIRAL BANDS AND BOOST THERMAL BUOYANCY AND THREATS FOR
   BRIEF SHALLOW SUPERCELLS...PARTICULARLY OVER SERN LA AND ADJACENT
   COASTAL MS THIS AFTN.  ABUNDANT LLVL SHEAR WILL BE FAVORABLE FOR A
   FEW TORNADOES WITHIN THE NE QUAD OF THE HYBRID SYSTEM.  THREAT WILL
   SPREAD FARTHER INLAND OVERNIGHT AS INFLUX OF THE TROPICAL
   ENVIRONMENT CONTINUES SLIGHTLY NWD AMIDST STRONG 0-1KM SRH.
   
   ...CNTRL/SRN PLAINS...
   COLD FRONT THAT WILL SURGE SEWD INTO SRN KS/NRN OK AND THE SRN HIGH
   PLAINS WILL BE FOCUS FOR SCATTERED TSTMS THROUGH TONIGHT. 
   THERMODYNAMIC SETUP...FEATURING STEEP LOW/MID-LVL LAPSE RATES AND
   MODEST LLVL MOISTURE WILL BE CONDUCIVE FOR MULTICELL CLUSTERS/BANDS
   OF STORMS WITH ISOLD DMGG WINDS/HAIL FROM THE MOUNTAINS OF SRN CO/NM
   INTO THE TX PNHDL...NRN OK AND SRN KS LATE THIS AFTN/EVE.
   
   ...APLCN MOUNTAIN REGION...
   A FEW TSTMS CAN BE EXPECTED THROUGH EARLY EVENING ALONG THE APLCN
   CREST AND ADJACENT FOOTHILLS.  STORMS WILL CONCENTRATE NEAR SHALLOW
   BACKDOOR FRONT...ESPECIALLY FROM CNTRL VA SWWD TOWARD THE NC BORDER
   AHEAD OF A WEAK SWD MOVING MCV. COMBINATION OF FAIRLY RICH MOISTURE
   WITH STRONG SFC HEATING SHOULD YIELD POCKETS OF SBCAPE TO 2000 J/KG.
    COUPLED WITH WEAK MEAN FLOW AND LIMITED FORCING FOR
   ASCENT...POTENTIAL WILL EXIST FOR PULSE STORMS WITH LOCALLY DMGG
   WIND AND POSSIBLY SVR HAIL.
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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