Categorical Graphic
Probabilistic Graphic
Probability of severe weather within 25 miles of a point. Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.

   SPC AC 261728
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1228 PM CDT TUE JUL 26 2011
   
   VALID 271200Z - 281200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MS RIVER
   VALLEY/CENTRAL PLAINS...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NORTH-CENTRAL HIGH
   PLAINS...
   
   ...SYNOPSIS...
   THE OVERALL LARGE SCALE PATTERN WILL FLUCTUATE LITTLE ON
   WEDNESDAY...ASIDE FROM A TREND TOWARD LOWER AMPLITUDE WESTERLIES
   OVER THE NORTHERN TIER TO THE NORTH OF AN EXTENSIVE UPPER RIDGE OVER
   THE SOUTHERN HALF THE CONUS. WITHIN THIS REGIME...AN UPPER TROUGH
   CURRENTLY OVER SOUTHERN QUEBEC/NORTHERN NEW ENGLAND WILL GRADUALLY
   SHIFT EASTWARD OVER/AWAY FROM MAINE ON WEDNESDAY...WHILE MULTIPLE
   LOW AMPLITUDE/CONVECTIVELY-DRIVEN SHORTWAVE TROUGHS CROSS THE
   MIDWEST/UPPER MS VALLEY.
   
   ...UPPER MIDWEST/UPPER MS RIVER VALLEY TO MIDDLE MO VALLEY...
   ONE OR MORE MCS/S ARE LIKELY TO BE ONGOING ACROSS THE REGION
   WEDNESDAY MORNING...MOST PROBABLE ACROSS PORTIONS OF MN/NORTHERN
   IA/NORTHERN WI/UPPER MI. A SEVERE THREAT CANNOT BE RULED OUT WITH
   THESE EARLY DAY STORMS...BUT MUCH OF THIS MORNING ACTIVITY WILL
   GENERALLY ENCOUNTER A MORE STABLE AIRMASS INTO NORTHEAST MN/NORTHERN
   WI/UPPER MI.
   
   INTO THE AFTERNOON...ON THE SOUTHERN FRINGE OF THIS EARLY DAY
   ACTIVITY...A CONVECTIVE OUTFLOW AUGMENTED/DIFFERENTIAL
   HEATING-INDUCED EFFECTIVE FRONTAL BOUNDARY WILL LIKELY SERVE AS THE
   FOCUS FOR SUBSEQUENT DEEP CONVECTIVE DEVELOPMENT WEDNESDAY
   AFTERNOON/EARLY EVENING. WHILE SOME MESOSCALE UNCERTAINTY
   EXISTS...SUCH INITIAL/RENEWED DIURNAL DEVELOPMENT SEEMS MOST
   PROBABLE WITHIN A WSW-ENE CORRIDOR ACROSS PORTIONS OF IA/SOUTHEAST
   MN INTO WESTERN/SOUTHERN WI WEDNESDAY AFTERNOON. HERE...A FAVORABLE
   NEAR-EFFECTIVE BOUNDARY COLOCATION OF VERTICAL SHEAR /DEEP LAYER 30
   KT OR MORE/ AND MODERATE INSTABILITY /2500-3500 J PER KG SBCAPE/
   WILL SUPPORT SUSTAINED MULTICELLULAR/SMALL LINEAR CLUSTERS AND SOME
   SUPERCELLS WITH DAMAGING WINDS/SEVERE HAIL AS THE PRIMARY HAZARDS
   WEDNESDAY AFTERNOON/EVENING.
   
   ...NEB/KS...
   AS A SOUTHEASTWARD-MOVING COLD FRONT GRADUALLY OVERTAKES A SURFACE
   TROUGH ACROSS THE CENTRAL PLAINS...A COMBINATION OF LOW LEVEL
   CONVERGENCE AND HOT TEMPERATURES NEAR/SOUTH OF THE FRONT
   /TEMPERATURES INTO THE 105 TO 110F RANGE/ SHOULD RESULT IN AT LEAST
   ISOLATED HIGH BASED STORMS WITHIN A CORRIDOR ACROSS EASTERN NEB AND
   NORTHERN/WESTERN KS. ON THE SOUTHERN EDGE OF THE STRONGER WESTERLIES
   ALOFT...DEEP LAYER SHEAR OF 20-25 KT WILL RESULT IN LOOSELY
   ORGANIZED MULTICELLULAR STORMS. THE MAIN SEVERE HAZARDS WILL BE
   DAMAGING WINDS LATE WEDNESDAY AFTERNOON/EVENING...WITH LOCALIZED
   SEVERE HAIL A POSSIBILITY AS WELL.
   
   ...NORTH-CENTRAL HIGH PLAINS...
   WEAK MOIST NEAR/POST-FRONTAL UPSLOPE TRAJECTORIES...AND PERHAPS AN
   EMBEDDED LOW AMPLITUDE SHORTWAVE TROUGH OR TWO...WILL CONTRIBUTE TO
   ISOLATED TO SCATTERED STRONG/SEVERE TSTM DEVELOPMENT WEDNESDAY
   AFTERNOON/EVENING ACROSS THE REGION. VEERING WIND PROFILES AND
   MODEST MOISTURE/POTENTIAL INSTABILITY...WITH A NARROW CORRIDOR OF
   SBCAPE OF 1000-2000 J/KG...WILL SUPPORT SUSTAINED STORMS/SOME
   SUPERCELLS CAPABLE OF SEVERE HAIL/WIND. STORMS SHOULD SPREAD
   EASTWARD ACROSS WESTERN SD/NORTHWEST NEB DURING THE EVENING...WITH A
   SEVERE THREAT CONTINUING ON AN INCREASINGLY ISOLATED/MARGINAL BASIS
   BY LATE EVENING/OVERNIGHT.
   
   ..GUYER.. 07/26/2011
   
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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z