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 151957
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0257 PM CDT SUN APR 15 2012
   
   VALID 152000Z - 161200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS FOR SRN MN...WRN WI...NERN IA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN TX NWD INTO THE UPPER
   MS VALLEY...
   
   ...CNTRL AND SRN MN...IA...WI...
   VISIBLE IMAGERY SHOWS CLEARING AND HEATING OCCURRING E OF THE COLD
   FRONT WHICH EXTENDED SWD ACROSS WRN IA EXTENDING FROM A SFC LOW OVER
   SERN SD. A WARM FRONT WAS SLOWLY LIFTING/MIXING NWD ACROSS THE
   MINNEAPOLIS AREA...EXTENDING EWD INTO NWRN WI. OBJECTIVE ANALYSIS
   INDICATES INSTABILITY INCREASING AS MOISTURE LIFTS NWD BENEATH
   COOLER LAPSE RATES ALOFT.  SHEAR IS VERY STRONG PER AREA VWPS AND
   FORECAST SOUNDINGS. THE 18Z OBSERVED MPX SOUNDING SUGGESTED THE WARM
   FRONT IS WEAKLY SLOPED AND WHEN MODIFIED FOR CURRENT
   CONDITIONS...REVEALS LITTLE CIN. STORMS ARE EXPECTED TO FORM E OF
   THE SURFACE LOW...NEAR THE COLD FRONT AND IMMEDIATELY ALONG THE WARM
   FRONT. SUPERCELLS WILL BE LIKELY WITH TORNADOES POSSIBLE. STORMS
   THAT FORM AND RIDE ALONG THE WARM FRONT MAY PRODUCE TORNADOES AND
   ALSO SWATHS OF DAMAGING WINDS. HAIL IS LIKELY AS WELL. THE THREAT
   SHOULD CONTINUE FOR A FEW HOURS INTO THE EVENING AS CELLS CONTINUE
   ACROSS WI.
   
   HAVE MOVED THE MDT RISK AREA BODILY NWD TO ACCOUNT FOR WARM FRONT
   POSITION AS WELL AS DRYING AND DECREASING CHANCES OF CONVECTION
   GENERALLY S OF I-80. 
   
   ...MO AND IL SWD ACROSS AR...LA...AND ERN TX...
   STORMS ALONG THE COLD FRONT FROM MO SWD INTO TX HAVE BEEN LARGELY
   UNDER PRODUCTIVE IN TERMS OF SEVERE THUS FAR...BUT EXTREME SHEAR
   PROFILES REMAIN AND THERE IS A CONDITIONAL THREAT OF DAMAGING WINDS
   AND A FEW TORNADOES. THIS WOULD BE MOST LIKELY WITH ACTIVITY THAT
   FORMS ON OR AHEAD OF THE FRONT...AND THAT CAN OUTRUN THE EWD MOVING
   OUTFLOW. SMALL BOWS AND A FEW SUPERCELLS OR EMBEDDED AREAS OF
   ROTATION MAY OCCUR.
   
   ..JEWELL.. 04/15/2012
   
   .PREV DISCUSSION... /ISSUED 1127 AM CDT SUN APR 15 2012/
   
   ...SYNOPSIS...
   UPPER TROUGH OVER THE PLAINS IS FORECAST TO LIFT NEWD DURING THE
   PERIOD REACHING THE UPPER MS VALLEY BY LATE TONIGHT.  ASSOCIATED
   SURFACE LOW OVER NERN NEB WILL MOVE TO THE NWRN IA/SWRN MN BORDER
   AREA BY THIS EVENING...THEN CONTINUE NEWD ACROSS NRN WI/UPPER MI AND
   SRN LAKE SUPERIOR BY 16/12Z. A WARM FRONT CURRENTLY EXTENDING FROM
   THE LOW ACROSS EXTREME WRN MN AND SRN WI IS EXPECTED TO GRADUALLY
   LIFT NWD...WITH INCREASING MOISTURE /SURFACE DEW POINTS IN THE LOW
   60S/ SPREADING NWD INTO SERN MN AND WI.  A COLD FRONT TRAILING SWD
   FROM THE LOW WILL ADVANCE MORE RAPIDLY ACROSS THE UPPER AND MIDDLE
   MS VALLEY TOWARD THE WRN GREAT LAKES DURING THE PERIOD...WITH THE
   SRN PART OF THE FRONT STALLING ACROSS ERN AND SRN TX TONIGHT.
   
   ...UPPER MS VALLEY REGION...
   VISIBLE SATELLITE IMAGERY SHOWS AN AREA OF THINNING CLOUDS FROM ERN
   NEB AND WRN IA INTO SRN MN...WHICH SHOULD SPREAD NEWD INTO PARTS OF
   NERN IA AND CENTRAL/SRN WI THIS AFTERNOON.  THIS WILL PROMOTE
   DIABATIC HEATING AND...WHEN COUPLED WITH AN INCREASE IN LOW LEVEL
   MOISTURE...CONTRIBUTE TO AIR MASS DESTABILIZATION WITH MLCAPE
   REACHING 1000-1500 J/KG.  DYNAMIC FORCING FOR LARGE SCALE ASCENT IN
   ADVANCE OF THE APPROACHING UPPER TROUGH COUPLED WITH LOW LEVEL
   CONVERGENCE NEAR THE SURFACE LOW AND ALONG THE FRONTAL BOUNDARIES IS
   EXPECTED TO RESULT IN CONVECTIVE INITIATION DURING THE AFTERNOON. 
   VERY STRONG WIND FIELDS AND ASSOCIATED PRONOUNCED DEEP-LAYER AND
   LOW-LEVEL SHEAR WILL SUPPORT ORGANIZED CONVECTIVE STRUCTURES
   INCLUDING FAST-MOVING SUPERCELLS.  LARGE HAIL...DAMAGING WIND
   GUSTS...AND TORNADOES /A FEW POTENTIALLY STRONG/...WILL BE POSSIBLE
   WITH THE STRONGER STORMS.  THE ACTIVITY WILL SPREAD EWD/NEWD THROUGH
   THE EVENING BEFORE STORMS GRADUALLY WEAKEN AFTER 03-06Z.
   
   ...MIDDLE MS VALLEY SSWWD INTO ERN TX/NWRN LA...
   PREFRONTAL BAND OF THUNDERSTORMS FROM SWRN MO INTO CENTRAL TX IS
   EXPECTED TO MOVE EWD THIS AFTERNOON AND EVENING...WITH STORMS LIKELY
   INTENSIFYING IN RESPONSE TO DIURNAL HEATING AND DESTABILIZATION
   /MLCAPE REACHING 1000-2000 J PER KG/.  WIND PROFILES EXHIBIT 50+ KT
   FLOW BEGINNING IN THE LOWEST 1-2 KM AGL...WITH THE RESULTANT INTENSE
   LOW LEVEL SHEAR/SRH AND STRONG DEEP LAYER SHEAR FAVORABLE FOR
   EMBEDDED SUPERCELLS AND BOW ECHOES WITHIN THE BAND.
   
   THERE IS POTENTIAL FOR ADDITIONAL STORMS TO DEVELOP FARTHER TO THE
   NORTHEAST INTO NERN MO AND IL THIS AFTERNOON AND EVENING AS DIABATIC
   HEATING AND LOW LEVEL MOISTENING RESULT IN DESTABILIZATION AND A
   WEAKENING OF THE CAP.  MODEL GUIDANCE INDICATES THAT THE STRONGEST
   LOW LEVEL WINDS WILL TRANSLATE NNEWD INTO THE MIDDLE MS VALLEY THIS
   AFTERNOON WITH LOW LEVEL AND DEEP LAYER SHEAR INCREASING WITH TIME. 
   THIS WILL FAVOR ORGANIZED CONVECTIVE STORMS INCLUDING POTENTIAL FOR
   A FEW SUPERCELLS TO DEVELOP...WITH AN ASSOCIATED THREAT FOR DAMAGING
   WIND GUSTS...LARGE HAIL...AND A FEW TORNADOES THROUGH THE EVENING
   HOURS.
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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