Oct 11, 2011 1630 UTC Day 1 Convective Outlook
Updated: Tue Oct 11 16:31:05 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20111011 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20111011 1630 UTC Day 1 Tornado Probabilities 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
20111011 1630 UTC Day 1 Damaging Wind Probabilities 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
20111011 1630 UTC Day 1 Large Hail Probabilities 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 111627
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1127 AM CDT TUE OCT 11 2011
   
   VALID 111630Z - 121200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER
   WRN PARTS OF TX/OK...
   
   ...CNTRL/SRN PLAINS...
   
   HEIGHT FALLS ASSOCIATED WITH EXIT REGION OF INTENSE UPPER-LEVEL JET
   STREAK PROPAGATING FROM THE PACIFIC NW AND CNTRL ROCKIES INTO THE
   CNTRL/SRN PLAINS WILL CONTRIBUTE TO AMPLIFICATION OF LARGE-SCALE
   TROUGH OVER THE CNTRL CONUS THIS PERIOD.  IN THE LOW LEVELS...LEE
   TROUGH OVER THE HIGH PLAINS WILL INTENSIFY TODAY AND GRADUALLY
   TRANSITION TO A PACIFIC FRONT WHILE PROGRESSING EWD INTO LOWER
   ELEVATIONS OF THE GREAT PLAINS.
   
   STEEPENING LOW- TO MIDLEVEL LAPSE RATES WILL COINCIDE WITH A
   MOISTENING BOUNDARY LAYER TO SUPPORT AIR MASS DESTABILIZATION TODAY
   E OF LEE TROUGH/PACIFIC FRONT.  INCREASING HIGH CLOUDS SPREADING EWD
   FROM THE ROCKIES MAY TEMPER DAYTIME HEATING AND THE DESTABILIZATION
   PROCESS...BUT AFTERNOON MLCAPE VALUES WILL STILL APPROACH 500-1000
   J/KG ACROSS THE WARM SECTOR.
   
   WATER VAPOR IMAGERY AND MODEL DIAGNOSTIC FIELDS INDICATE A LEAD
   SHORT-WAVE TROUGH OVER ERN PARTS OF CO/NM WHICH WILL CONTINUE EWD. 
   EXTRAPOLATION OF CURRENT MOTION SUGGESTS THAT THE STRONGER FORCING
   FOR ASCENT WILL LIKELY SHIFT E OF THE SURFACE TROUGH/FRONT PRIOR TO
   PEAK HEATING.  NONETHELESS...THE TRAILING INFLUENCE OF THIS FEATURE
   WILL COMBINE WITH LOW-LEVEL ASCENT ALONG INTENSIFYING SURFACE
   BOUNDARY TO FOSTER ISOLATED TO WIDELY SCATTERED TSTMS LATER THIS
   AFTERNOON INTO EVENING.  WHILE ISOLATED SEVERE STORMS CAPABLE OF
   HAIL AND GUSTY WIND WILL BE POSSIBLE ALONG THE LENGTH OF THE LEE
   TROUGH/PACIFIC FRONT...THE GREATEST POTENTIAL FOR ORGANIZED STORM
   MODES --INCLUDING SUPERCELLS-- APPEARS TO BE OVER PARTS OF THE TX/OK
   PNHDLS INTO NWRN TX AND WRN OK.  HERE...THE EXIT REGION OF MID- AND
   HIGH-LEVEL JET STREAKS WILL ENHANCE DEEP-LAYER SHEAR WITHIN A
   KINEMATIC ENVIRONMENT EXHIBITING VERTICALLY VEERING WINDS WITH
   HEIGHT.  LARGE HAIL APPEARS TO BE THE PRIMARY HAZARD...THOUGH
   LOCALLY DAMAGING WIND GUSTS WILL BE POSSIBLE...ESPECIALLY AS STORMS
   DEVELOP A COLD POOL.
   
   ...FAR ERN NC...
   
   WEAK SURFACE LOW OFF THE SC COAST WILL CONTINUE TO DEVELOP NWD ALONG
   COASTAL BOUNDARY THIS PERIOD...POTENTIALLY ALLOWING A NARROW AXIS OF
   HIGHER THETA-E AIR TO OVERSPREAD THE IMMEDIATE COAST AND THE OUTER
   BANKS.  SHOULD THIS OCCUR...ISALLOBARICALLY BACKED NEAR-SURFACE FLOW
   --AND RESULTANT ENHANCEMENT OF LOW-LEVEL SHEAR-- WILL SUPPORT THE
   POTENTIAL FOR BRIEF SUPERCELL STRUCTURES WITH A LOW PROBABILITY RISK
   FOR A TORNADO.
   
   ..MEAD/ROGERS.. 10/11/2011
   
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