SPC AC 041243
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0743 AM CDT WED AUG 04 2004
   
   VALID 041300Z - 051200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 NNW
   JHW 10 E DUJ 35 SE MGW 30 W BKW 45 N MSL 50 SW JBR 30 ESE FYV 30 NNE
   JLN 25 N COU 10 E DTW.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 65 NNE
   OLF 45 N REJ 35 S PHP 35 NNW MHN 30 S MHN 30 NNW GLD 25 SSE DEN 20
   WSW DGW 45 WSW BIL 50 NE CTB.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 SSE LRD 15 ESE NIR
   40 SE AUS 20 W LFK 45 NNE LFK 30 SSW GGG 35 WNW TPL 70 E FST 70 S
   MRF ...CONT... 65 S GBN 20 NE GBN 30 SW PRC 60 WNW GCN 15 NNE U24 45
   ENE ENV 45 NW PIH 65 NE BOI 30 NNE BNO 25 S MHS 25 ENE ACV 15 ENE
   4BK 25 ESE AST 15 NW CLM ...CONT... 50 N ISN 25 E PIR 15 ENE YKN 20
   NNW FRM 10 SE LNR 40 NNE MTC ...CONT... 25 W ART 20 SSW PSM
   ...CONT... 20 ESE NEL 50 NNE HKY 35 E ANB 25 E AGS 10 E GSB 20 NE
   HSE.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MS VALLEY ACROSS
   THE OH VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN AND CNTRL
   HIGH PLAINS...
   
   ...SYNOPSIS...
   AMPLIFIED LARGE-SCALE PATTERN WILL PERSIST OVER THE CONUS THIS
   FORECAST PERIOD. DOMINANT RIDGE WILL REMAIN ANCHORED OVER THE SRN
   ROCKIES...BETWEEN TROUGHS OVER THE PACIFIC NW AND ERN THIRD OF THE
   NATION.  HEIGHT FALLS ASSOCIATED WITH WEAK DISTURBANCES MOVING OUT
   OF THE MIDWEST IN CONJUNCTION WITH SHORTWAVE TROUGH DIVING SWD
   ACROSS WRN ONTARIO WILL LEAD TO OVERALL AMPLIFICATION OF ERN U.S.
   TROUGH.
   
   AT THE SURFACE...MORNING MESOANALYSIS INDICATES SEVERAL WEAK WAVES
   ALONG BAROCLINIC ZONE STRETCHING FROM THE CNTRL PLAINS ACROSS THE
   SRN GREAT LAKES. WWD EXTENSION OF THIS FEATURE THEN STRETCHES NWWD
   INTO THE NRN ROCKIES. IT APPEARS THAT GREATEST CONCENTRATION OF
   SEVERE WEATHER WILL BE FOCUSED ALONG OH VALLEY PART OF FRONT AND
   LARGE COMPOSITE OUTFLOW BOUNDARY...AS WELL THAT PORTION OVER THE NRN
   HIGH PLAINS.
   
   ...MID MS VALLEY EWD ACROSS THE OH VALLEY...
   WATER VAPOR IMAGERY AND REGIONAL RADAR MOSAIC INDICATE TWO
   WELL-DEFINED VORTICITY MAXIMA/MCV/S THIS MORNING...ONE OVER SERN
   LOWER MI AND THE OTHER OVER NWRN IND. THESE FEATURES...IN PART...
   HAVE BEEN RESPONSIBLE FOR THE WIDESPREAD...PRE-FRONTAL CONVECTIVE
   BAND WHICH HAS PERSISTED OVERNIGHT. REGIONAL 12Z SOUNDINGS INDICATE
   RELATIVELY WEAK MID-LEVEL LAPSE RATES...LARGELY AS A RESULT OF
   CONVECTIVE PROCESSING...WHICH WILL TEND TO LIMIT THE OVERALL
   DESTABILIZATION PROCESS. HOWEVER...PRESENCE OF RICH LOW-LEVEL
   MOISTURE /CHARACTERIZED BY LOWER TO MID 70S DEWPOINTS/ SHOULD
   CONTRIBUTE TO POCKETS OF MODERATE AFTERNOON INSTABILITY WITH MLCAPES
   APPROACHING 2000-3000 J/KG...ESPECIALLY OVER PARTS OF THE LOWER OH
   VALLEY.
   
   IT APPEARS THAT GREATEST SEVERE WEATHER POTENTIAL WILL LIKELY OCCUR
   ALONG COMPOSITE OUTFLOW BOUNDARY /DISPLACED SWD FROM MAIN SYNOPTIC
   BOUNDARY/...ESPECIALLY AS CONSOLIDATING SURFACE LOW DEVELOPS EWD
   ACROSS THE LOWER/MIDDLE OH VALLEY. RATHER STRONG ZONAL WIND FIELDS
   OBSERVED ON THE 12Z ILX SOUNDING /NAMELY THE LOWEST 3-4KM AGL/
   SUGGEST THE LIKELIHOOD OF DAMAGING WINDS...ESPECIALLY WITH ANY
   EVOLVING BOW/LEWP STRUCTURES. EXCEPTION WILL BE ALONG AND E OF
   MIGRATORY SURFACE LOW TRACK WHERE LOCALLY-BACKED SURFACE WINDS WILL
   ENHANCE POTENTIAL FOR SUPERCELLS AND ISOLATED TORNADOES.
   
   ...NRN/CNTRL HIGH PLAINS...
   CURRENT SURFACE OBSERVATIONS INDICATE MODEST LOW-LEVEL MOISTURE
   PRESENT IN POST-FRONTAL AIRMASS WITH DEWPOINTS MAINLY IN THE 50S.
   WHEN COUPLED WITH RATHER STEEP LAPSE RATES /OBSERVED ON 12Z RAP/DNR
   SOUNDINGS/...AIRMASS SHOULD BECOME MODERATELY UNSTABLE IN A CORRIDOR
   FROM CNTRL/ERN MT SEWD ACROSS ERN WY/WRN SD/NEB PNHDL. OROGRAPHIC
   ASCENT...CONVERGENCE ALONG FRONT AND DAYTIME HEATING SHOULD ALL AID
   IN TSTM DEVELOPMENT LATER TODAY ALONG WRN EDGE OF DEVELOPING
   INSTABILITY AXIS. 30-40KT WLY MID-LEVEL FLOW ATOP SELY SURFACE WINDS
   WILL RESULT IN MORE THAN SUFFICIENT DEEP-LAYER SHEAR FOR ISOLATED
   SUPERCELLS CAPABLE OF LARGE HAIL AND A FEW STRONG WIND GUSTS.
   
   ...PACIFIC NW...
   STRONG SHORTWAVE TROUGH /NEAR 47N AND 135W/ IS FORECAST TO MOVE
   THROUGH MEAN TROUGH POSITION AND EJECT NEWD ACROSS WA/ORE THIS
   EVENING AND TONIGHT. THOUGH INSTABILITY IS EXPECTED TO REMAIN
   WEAK...STEEP LAPSE RATES /PER 12Z SOUNDINGS/...CONVERGENCE ALONG
   APPROACHING COLD FRONT AND ASCENT ALONG WINDWARD SIDE OF CASCADES
   MAY BE SUFFICIENT TO INITIATE A FEW STRONG STORMS CAPABLE OF
   MARGINAL WIND/HAIL DURING THE LATTER HALF OF THE FORECAST PERIOD.
   
   ..MEAD/BRIGHT.. 08/04/2004
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 1630Z