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 201958
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0258 PM CDT WED JUN 20 2012
   
   VALID 202000Z - 211200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM WRN UPPER MI TO IA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM S-CNTRL KS TO THE NRN TX
   PANHANDLE...
   
   ...MN/WI/IA/UPPER MI...
   MINIMAL CHANGE TO SEVERE PROBABILITIES WITH PREVIOUS FORECAST ON
   TRACK. CONVECTION WILL CONTINUE TO INCREASE WITHIN A COLD FRONTAL
   ZONE EXTENDING FROM E-CNTRL MN TO SERN NEB. A PRE-FRONTAL WIND SHIFT
   AND EXTENSIVE STRATOCU DECK IS LIMITING STRONGER HEATING/STEEPER
   LOW-LEVEL LAPSE RATES. STILL...MODERATE BUOYANCY AND STRONG
   DEEP-LAYER SWLYS PARALLELING THE BOUNDARY SHOULD BE SUFFICIENT FOR A
   COUPLE OF BOW/LEWP STRUCTURES CAPABLE OF ISOLATED DAMAGING
   WIND/SEVERE HAIL. 
   
   ...KS/OK/TX...
   MINOR TWEAKS TO SEVERE PROBABILITIES BASED ON CURRENT FRONTAL
   POSITION IN N-CNTRL KS TO THE NWRN TX PANHANDLE. ALTHOUGH ISOLATED
   TO SCATTERED TSTMS WILL DEVELOP ALONG THE FRONT...WINDS ARE
   CURRENTLY DECREASING WITH HEIGHT PER AREA PROFILER/VWP DATA.
   HIGHER-LEVEL NWLYS SHOULD STRENGTHEN SOMEWHAT ON THE GLANCING
   INFLUENCE OF THE SPEED MAX EJECTING ACROSS NERN CO INTO NEB. THIS
   SHOULD RENDER MARGINALLY ORGANIZED UPDRAFTS WITH A RISK FOR ISOLATED
   DAMAGING WINDS/SEVERE HAIL.
   
   ...NY/VT...
   NO CHANGES MADE TO PREVIOUS FORECAST.
   
   ..GRAMS.. 06/20/2012
   
   .PREV DISCUSSION... /ISSUED 1127 AM CDT WED JUN 20 2012/
   
   ...MN/WI/IA...
   AN EXPANSIVE UPPER RIDGE IS PRESENT TODAY OVER MOST OF THE EASTERN
   AND SOUTHERN STATES...WHILE AN UPPER TROUGH DOMINATES THE WEATHER
   OVER THE NORTHERN PLAINS.  THE PRIMARY SURFACE BOUNDARY ASSOCIATED
   WITH THE TROUGH EXTENDS FROM NORTHWEST WI INTO CENTRAL NEB...THEN
   SOUTHWESTWARD INTO THE OK/TX PANHANDLES.  THIS BOUNDARY WILL BE THE
   FOCUS FOR SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING.  
   
   A FAST-MOVING CLUSTER OF STORMS NEAR DLH WILL MOVE INTO LAKE
   SUPERIOR SOON.  HOWEVER...CONVERGENCE ALONG THE TRAILING SURFACE
   BOUNDARY WILL LIKELY RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT
   OVER PARTS OF WESTERN WI...SOUTHEAST MN...AND EASTERN IA BY MID/LATE
   AFTERNOON.  THE AIR MASS AHEAD OF THE BOUNDARY IS QUITE MOIST AND
   WILL BECOME MODERATELY UNSTABLE WITH MLCAPE VALUES OVER 2000 J/KG. 
   STEERING FLOW PARALLEL WITH THE BOUNDARY WILL LIKELY RESULT IN A
   LONG SQUALL LINE THIS EVENING ALONG THE BOUNDARY AS IT MOVES ACROSS
   THE SLIGHT RISK AREA.  LAPSE RATES ARE NOT PARTICULARLY STEEP...BUT
   THE POTENTIAL EXISTS FOR A FEW BOW/LEWP STRUCTURES ALONG THE LINE
   RESULTING IN CORRIDORS OF DAMAGING WINDS AND HAIL.
   
   ...KS/OK/TX...
   MORNING SURFACE ANALYSES SHOW A COLD FRONT SURGING SOUTHWARD ALONG
   THE CENTRAL HIGH PLAINS.  THIS BOUNDARY WILL LIKELY EXTEND FROM
   NORTHEAST NM INTO SOUTH-CENTRAL KS BY LATE AFTERNOON.  FULL HEATING
   WILL RESULT IN DEEP MIXING AND HELP WEAKEN THE CAP...RESULTING IN
   SCATTERED THUNDERSTORM DEVELOPMENT ALONG THE FRONT.  30+ DEGREE
   SURFACE T-TD SPREADS...STEEP LOW LEVEL LAPSE RATES...MLCAPE VALUES
   OVER 2000 J/KG...AND STRENGTHENING NORTHWESTERLY MID LEVEL WINDS
   WILL COMBINE TO YIELD A RISK OF ISOLATED SEVERE STORMS.  LOCALLY
   DAMAGING WINDS WILL BE THE MAIN THREAT...ALTHOUGH HAIL IS ALSO
   POSSIBLE IN THE STRONGEST STORMS.
   
   ...NY/VT...
   MODELS DIFFER ON EXTENT OF CONVECTION THAT WILL AFFECT NY/NEW
   ENGLAND THIS AFTERNOON AND EVENING.  THE AREA MOST LIKELY TO SEE A
   FEW THUNDERSTORMS WILL BE ACROSS NORTHEAST NY AND NORTHERN VT.  IF
   STORMS CAN FORM IN THIS AREA...RATHER STRONG NORTHWESTERLY MID/UPPER
   LEVEL FLOW COMBINED WITH MODERATE INSTABILITY WILL POSE A RISK OF A
   FEW STRONG/SEVERE STORMS CAPABLE OF GUSTY WINDS AND HAIL.
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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