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 010558
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1258 AM CDT TUE MAY 01 2012
   
   VALID 011200Z - 021200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE ERN DAKOTAS AND
   NEB...NERN KS...IA...MOST OF MN AND WRN WI...
   
   ...SYNOPSIS...
   A LOW AMPLITUDE SHORTWAVE TROUGH WILL MOVE FROM THE MO VALLEY ENEWD
   ACROSS THE OH VALLEY REGION DURING THE DAY...HELPING TO MOVE
   MOISTURE AND INSTABILITY NEWD WITH A THREAT OF SEVERE HAIL AND WIND.
   MEANWHILE...A MORE SUBSTANTIAL UPPER TROUGH WILL MOVE INTO THE NRN
   PLAINS WITH LOW PRESSURE DEEPENING ACROSS THE DAKOTAS INTO WRN MN
   SWWD ACROSS NEB. BOTH SHEAR AND INSTABILITY WILL BE FAVORABLE FOR
   SEVERE STORMS 
   
   ...MID MO INTO THE UPPER MS VALLEY...
   SCATTERED WARM ADVECTION STORMS MAY EXIST ACROSS MN AND IA EARLY
   NEAR A WARM FRONT...WITH A MARGINAL HAIL THREAT. THEN...STRONG SLY
   FLOW WILL BRING MID 60S F BOUNDARY LAYER DEWPOINTS NWD INTO THE
   REGION...CREATING STRONG INSTABILITY OVER THE WARM SECTOR.
   CONVERGENCE WILL INCREASE ALONG THE COLD FRONT/SURFACE TROUGH. GIVEN
   LITTLE IF ANY CONVECTIVE INHIBITION...STORMS SHOULD ERUPT BY
   21Z...BEGINNING OVER NRN MN NEAR THE SURFACE LOW...THEN FARTHER SWWD
   ALONG THE SFC TROUGH. WIND PROFILES WILL FAVOR SUPERCELLS...WITH
   VERY LARGE HAIL LIKELY. 
   
   LOW LEVEL SHEAR MAY BE ENHANCED OVER CNTRL/NRN MN DUE TO THE EFFECTS
   OF EARLY CONVECTION AND WHERE A WARM FRONT WILL HOLD. AS A
   RESULT...A FEW TORNADOES MAY OCCUR. A STRONG TORNADO CANNOT BE RULED
   OUT IF LOW LEVEL SHEAR ENDS UP BEING AS STRONG AS SOME OF THE NAM
   FORECAST SOUNDINGS INDICATE. HOWEVER...THERE ARE VARYING MODEL
   SOLUTIONS...AND WILL MAINTAIN ISOLATED TORNADO THREAT AT THIS TIME.
   
   ...LOWER MO INTO THE OH VALLEY...
   NUMEROUS STORMS WILL BE ONGOING OVER MUCH OF MO AND NRN AR TUE
   MORNING SUPPORTED BY AN UPPER SHORTWAVE TROUGH AND WARM ADVECTION
   WITH A SWLY LOW LEVEL JET. THIS ACTIVITY WILL LIKELY SHIFT NEWD WITH
   THE UPPER WAVE...WITH AN ISOLATED WIND AND HAIL THREAT OVER A LARGE
   AREA. STORMS WILL LIKELY REGENERATE ON OLD OUTFLOW AND THE LOCATION
   OF THE STRONGEST STORMS WILL DEPEND ON WHERE POCKETS OF INSTABILITY
   CAN DEVELOP...MOST LIKELY ON SWRN FLANKS OF EARLY STORMS. WITH
   HEATING EXPECTED OVER TN AND SRN KY...THE ZONE OF SEVERE MAY EXTEND
   ROUGHLY FROM ST. LOUIS TO LOUISVILLE. UNCERTAINTY REGARDING LOCATION
   OF OUTFLOW BOUNDARIES WILL MARGINAL DEEP SHEAR WILL PRECLUDE A
   SLIGHT AT THIS TIME.
   
   ..JEWELL/GARNER.. 05/01/2012
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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