SPC AC 300555
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1255 AM CDT FRI APR 30 2004
   
   VALID 301200Z - 011200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 60 NNW
   ABI 25 SE CSM 15 SSE END 30 WSW CNU SZL 30 SW UIN 25 NW PIA 20 E MMO
   20 NNW LAF 15 SE HUF 20 WNW CGI 45 WSW ARG 30 SSE HOT 25 NNW LFK 45
   SW CLL 60 W COT 40 NW DRT 60 NNW ABI.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 S VCT NIR 40 NW
   ALI 10 S LRD.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 SE P07 35 E HOB 40
   WNW ROW 25 NNW ONM 50 SW FMN 45 SE CNY 30 SW CAG 15 NNW DEN 40 NNW
   LHX 30 ENE LAA 50 SSW HLC 40 NNW CNK 15 SW OMA 25 ENE FOD LSE 15 SE
   APN.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 NW EPM 10 N MWN 35
   WSW SHD 20 ESE ROA 40 ESE EWN.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM SWRN TX ACROSS THE MID MS
   VALLEY INTO IL...
   
   ...SRN PLAINS...
   
   EARLY MORNING WATER VAPOR IMAGERY SUPPORTS LATEST MODEL GUIDANCE
   WITH UPPER LOW DIGGING ESEWD ACROSS THE SRN ROCKIES INTO WEST TX
   LATE IN THE PERIOD.  THIS LOW LATITUDE FEATURE WILL PROVE FAVORABLE
   FOR A MORE AGGRESSIVE SWD PLUNGE OF COLD BOUNDARY LAYER AIRMASS INTO
   THE SRN HIGH PLAINS.  00Z MODELS ARE TOO PASSIVE ALLOWING COLD FRONT
   TO SURGE INTO NWRN TX...POSSIBLY 06-12HR TOO SLOW ACROSS SOME OF THE
   REGION.  BASED ON THIS BIAS...STRONG SFC HEATING WILL BE LIMITED TO
   AN AXIS FROM SWRN TX INTO NCNTRL TX.  IT SEEMS REASONABLE TO EXPECT
   THUNDERSTORMS TO INITIATE ALONG DRYLINE/COLD FRONT INTERSECTION
   NORTH OF SJT OR WEST OF FTW...WITH NEWD EXPANSION/INTENSIFICATION AS
   UPPER TROUGH MID LEVEL COLD ADVECTION SPREAD ACROSS WARM SECTOR.
   
   BEFORE THE AFOREMENTIONED SCENARIO UNFOLDS...IT APPEARS LOW LEVEL
   WARM ADVECTION WILL DRIVE AN EARLY MORNING MCS ACROSS MUCH OF OK. 
   ELEVATED THUNDERSTORMS MAY PRODUCE ISOLATED LARGE HAIL BEFORE
   WEAKENING BY MID MORNING.  LATE AFTERNOON ACTIVITY WILL DEVELOP
   WITHIN AN AXIS OF STRONG INSTABILITY WHERE SFC DEW POINTS HAVE RISEN
   WELL INTO THE MID-UPPER 60S F. CAPE VALUES WILL EXCEED 3000 J/KG AS
   DEEP LAYER FLOW INCREASES SUFFICIENTLY TO SUPPORT SUPERCELL
   DEVELOPMENT.  EARLY STORM MODE ALONG DRY LINE/COLD FRONT MAY PROVE
   DISCRETE...BUT QUICKLY EVOLVE INTO A SQUALL LINE AS UPPER FORCING
   SPREADS ACROSS WARM SECTOR.  LINEAR MCS WILL PROGRESS ACROSS MUCH OF
   THE SRN PLAINS INTO WRN AR DURING THE OVERNIGHT HOURS. VERY LARGE
   HAIL AND DAMAGING WINDS ARE THE PRIMARY SEVERE THREATS.
   
   
   ...MID MS VALLEY/OH VALLEY...
   
   FARTHER NORTHEAST ALONG THE COLD FRONT...INSTABILITY WILL BE MUCH
   WEAKER AS MULTIPLE SRN STREAM CONVECTIVE SYSTEMS PREVENT SIGNIFICANT
   MOISTURE RETURN INTO THE OH VALLEY.  HOWEVER...STRONG HEIGHT FALLS
   AHEAD OF DEEPENING TROUGH OVER THE UPPER MS VALLEY WILL ENHANCE A
   NARROW ZONE OF DEEP CONVERGENCE ALONG FRONTAL ZONE INTO PORTIONS OF
   THE OH VALLEY. DEEP LAYER SHEAR WILL PROVE MORE THAN ADEQUATE FOR
   ORGANIZED DEEP CONVECTION CAPABLE OF PRODUCING LOCALLY DAMAGING
   WINDS OR LARGE HAIL.
   
   
   ...CENTRAL GULF COAST...
   
   EARLY MORNING WATER VAPOR IMAGERY SUGGESTS AN UPPER TROUGH AXIS IS
   SHIFTING EWD ACROSS NRN MEXICO INTO WEST TX.  THIS FEATURE WILL MOVE
   ACROSS THE LOWER MS VALLEY INTO THE CENTRAL GULF COAST STATES DURING
   PEAK HEATING.  MARITIME AIRMASS HAS MOVED INLAND WITH HIGH BOUNDARY
   LAYER MOISTURE CHARACTERIZED BY LOWER 70S SFC DEW POINTS.  LARGE
   SCALE ASCENT SHOULD ENHANCE CONVECTIVE THREAT ACROSS MUCH OF THIS
   REGION BY EARLY AFTERNOON...MOST LIKELY TO THE EAST OF THE MS RIVER.
    RELATIVELY WEAK DEEP LAYER SHEAR WILL RESULT IN MULTICELL CLUSTERS
   CAPABLE OF PRODUCING ISOLATED HAIL/WIND DAMAGE.
   
   ..DARROW/BANACOS.. 04/30/2004
   
   ...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 1300Z