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 190046
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0746 PM CDT THU AUG 18 2011
   
   VALID 190100Z - 191200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE ERN DAKOTAS INTO
   PORTIONS OF MO...
   
   ...MID-LOWER MO VALLEY/CNTRL PLAINS...
   
   A LARGE CONGLOMERATE OF MULTI-CELL AND SUPERCELL UPDRAFTS ARE
   EVOLVING INTO AN MCS OVER THE MID MO VALLEY REGION OF NEB/IA INTO
   NWRN MO THIS EVENING.  LEADING EDGE OF THIS ACTIVITY IS PROPAGATING
   SEWD AT ROUGHLY 30-35KT ALONG A WELL DEFINED INSTABILITY GRADIENT
   THAT IS SUPPLYING TSTMS WITH 3000-5000 J/KG MUCAPE.  LATEST RADAR
   DATA SUGGESTS SEVERAL OF THE STRONGER CORES ARE LIKELY PRODUCING
   HAIL IN EXCESS OF 2 INCHES AND THESE LARGER HAILSTONES MAY BE NOTED
   FOR THE NEXT SEVERAL HOURS AS INFLOW REMAINS FAVORABLE FOR
   MOIST/BUOYANT UPDRAFTS.  IF ACTIVITY EVOLVES AS EXPECTED...MCS
   SHOULD EASILY SURGE SSEWD ACROSS NWRN MO/EXTREME NERN KS INTO
   PORTIONS OF CNTRL MO BEFORE GRADUALLY WEAKENING DURING THE OVERNIGHT
   HOURS OVER SRN MO.  PRIOR TO LATE NIGHT WEAKENING DAMAGING WINDS MAY
   BECOME MORE COMMON AS OUTFLOW SURGES ALONG GRADUALLY EXPANDING
   PRECIP SHIELD. 
   
   FRONTAL CONVECTION HAS GRADUALLY INTENSIFIED/EXPANDED ACROSS SD
   AHEAD OF SHORTWAVE TROUGH THAT EXTENDS ACROSS MB INTO THE DAKOTAS. 
   WITH FAVORABLE DEEP LAYER SHEAR AND MODEST LARGE SCALE SUPPORT IT
   APPEARS TSTMS THAT EVOLVE ACROSS THIS REGION WILL CONTINUE TO
   SPREAD/DEVELOP EWD INTO PORTIONS OF WRN MN LATE.  LARGE HAIL AND
   DAMAGING WINDS REMAIN POSSIBLE WITH THE STRONGER STORMS.
   
   ...MIDDLE ATLANTIC/NERN U.S...
   
   DIURNAL HEATING PROVED INSTRUMENTAL IN AIRMASS DESTABILIZATION
   ACROSS THE MIDDLE ATLANTIC/NERN U.S. TODAY.  DESPITE WEAK VERTICAL
   SHEAR A SUBSTANTIAL NUMBER OF STRONG/SEVERE TSTMS DEVELOPED ACROSS
   NRN VA...SPREADING ACROSS THE DELMARVA INTO NJ OVER THE LAST HOUR OR
   SO.  THIS ACTIVITY HAS OVERTURNED MUCH OF THE INSTABILITY EARLIER
   NEEDED FOR UPDRAFT INTENSITY AND WITH LOSS OF HEATING IT APPEARS
   REMAINING STORMS WILL MEANDER ABOUT AND WEAKEN QUICKLY AFTER SUNSET.
   
   ..DARROW.. 08/19/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z