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 170558
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1258 AM CDT SUN JUN 17 2012
   
   VALID 171200Z - 181200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF ERN SD...SW MN
   AND FAR NW IA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS
   AND UPPER MS VALLEY...
   
   SEVERE WEATHER EVENT WITH TORNADOES AND VERY LARGE HAIL APPEARS
   LIKELY ACROSS THE NRN PLAINS AND UPPER MS VALLEY THIS AFTERNOON INTO
   TONIGHT...
   
   ...NRN PLAINS/UPPER MS VALLEY...
   ZONAL WLY FLOW WILL EXIST ACROSS THE NCNTRL STATES TODAY AS THE EXIT
   REGION OF A MID-LEVEL JET MOVES INTO THE REGION FROM THE WEST. THIS
   FEATURE WILL HELP CREATE STRONG DEEP LAYER SHEAR PROFILES FAVORABLE
   FOR SEVERE STORMS. AT THE SFC...A LOW IS FORECAST TO DEEPEN ACROSS
   ECNTRL SD WITH A CORRIDOR OF LOW-LEVEL MOISTURE EXTENDING FROM THE
   MID-MO VALLEY NWD INTO ERN SD AND SW MN BY LATE AFTERNOON. SFC
   DEWPOINTS APPEAR LIKELY TO REACH THE MID TO UPPER 60S F WITH
   MODERATE TO STRONG INSTABILITY IN PLACE BY AFTERNOON ACROSS THE WARM
   SECTOR. THE MODELS ARE IN GENERALLY GOOD AGREEMENT DEVELOPING
   THUNDERSTORMS IN ERN SD AND MOVING AN CLUSTER OF STRONG CONVECTION
   EWD ACROSS SRN MN THIS EVENING.
   
   FORECAST SOUNDINGS AT 00Z/MON IN ERN SD SHOW MLCAPE FROM 2500 TO
   3000 J/KG WITH AN IMPRESSIVE SHEAR ENVIRONMENT. 0-6 KM SHEAR IS
   FORECAST TO INCREASE DURING THE DAY REACHING 50 TO 55 KT BY EARLY
   EVENING. THIS ALONG WITH A STRENGTHENING 40 TO 50 KT LOW-LEVEL JET
   SHOULD BE FAVORABLE FOR TORNADIC SUPERCELLS. FORECAST SOUNDINGS NEAR
   AND JUST EAST OF ABERDEEN AT 00Z/MON SHOW 0-3 KM STORM RELATIVE
   HELICITIES OF 350 TO 400 M2/S2 WITH LCL HEIGHTS AROUND 700 METERS
   SUGGESTING A THREAT FOR STRONG TORNADOES WILL BE POSSIBLE. IN
   ADDITION...SUPERCELLS SHOULD CONTAIN LARGE HAIL WITH HAIL GREATER
   THAN 2 INCHES IN DIAMETER POSSIBLE WITH THE MORE DOMINANT ROTATING
   STORMS. AS STORM COVERAGE INCREASES DURING THE EVENT...A LINE OF
   STORMS COULD ORGANIZE ACROSS SRN MN WITH DISCRETE ROTATING CELLS
   EMBEDDED IN THE LINE. THE STRONG SHEAR AND WELL-DEVELOPED LOW-LEVEL
   JET SHOULD HELP THE TORNADO THREAT TO CONTINUE INTO THE EVENING.
   HOWEVER...A GRADUAL TRANSITION TO A WIND DAMAGE THREAT SHOULD TAKE
   PLACE DURING THE EARLY TO MID EVENING. THE LINE COULD MOVE ESEWD
   INTO CNTRL AND ERN IA BY LATE IN THE EVENING. THE SEVERE THREAT
   SHOULD DROP OFF QUICKLY TO THE SOUTHWEST OF THE MCS MAINLY DUE TO
   WARMING MID-LEVEL TEMPS.
   
   ...LOWER GREAT LAKES/UPPER OH VALLEY...
   A SHORTWAVE TROUGH IS FORECAST TO MOVE ACROSS THE GREAT LAKES REGION
   TODAY. AHEAD OF THE SHORTWAVE TROUGH...AN AXIS OF MODERATE
   INSTABILITY SHOULD DEVELOP FROM THE OH VALLEY NEWD INTO THE LOWER
   GREAT LAKES. THUNDERSTORM DEVELOPMENT SHOULD OCCUR ALONG THE
   INSTABILITY AXIS THIS AFTERNOON AS SFC TEMPS WARM. FORECAST
   SOUNDINGS NEAR CLEVELAND AND CINCINNATI THIS AFTERNOON SHOW MLCAPE
   VALUES AROUND 2000 J/KG WITH 20 TO 25 KT OF LOW-LEVEL FLOW. THIS
   ALONG WITH STEEP LOW-LEVEL LAPSE RATES COULD BE SUFFICIENT FOR
   MARGINALLY SEVERE WIND GUSTS WITH THE STRONGER CELLS LATE THIS
   AFTERNOON.
   
   ...SRN PLAINS...
   MODERATE TO STRONG INSTABILITY IS SHOULD BE IN PLACE THIS AFTERNOON
   ACROSS MUCH OF THE SRN PLAINS WHERE THE MODELS DEVELOP SCATTERED
   THUNDERSTORMS. ALTHOUGH DEEP LAYER SHEAR IS FORECAST TO BE AT OR
   BELOW 30 KT ACROSS MUCH OF THE WARM SECTOR...STEEP LOW-LEVEL LAPSE
   RATES AND SFC DEWPOINTS IN THE MID 60S F MAY BE ENOUGH FOR A
   MARGINAL WIND DAMAGE THREAT WITH THE STRONGER UPDRAFTS. HAIL MAY
   ALSO OCCUR IN AREAS WHERE CONVECTION HAS ACCESS TO MAXIMIZED
   INSTABILITY.
   
   ..BROYLES/GARNER.. 06/17/2012
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z