SPC AC 301635
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1135 AM CDT FRI APR 30 2004
   
   VALID 301630Z - 011200Z
   
   THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 WNW
   ACT 25 SW BWD 35 WSW ABI 25 WNW ABI 40 NE ABI 10 SE SPS 40 WSW ADM
   15 S DUA 45 SW PRX 25 WNW ACT.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 50 NW
   DRT 50 NE BGS 70 WSW SPS 30 WSW OKC 30 SE PNC 20 S CNU 30 W JEF 10 S
   UIN 40 NE UIN 25 NNE PIA 30 ESE MMO 45 S SBN 25 WNW MIE 20 ESE BMG
   50 ENE PAH 35 SSE TYR 15 NNW AUS 65 W COT.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 ESE P07 65 E FST
   MAF 35 N GDP 15 NE SVC 80 E SOW 60 WSW FMN 45 WSW MTJ 30 SSE CAG 20
   SSW FCL 15 NE LHX 20 E GCK CID 25 SSE OSC ...CONT... 25 ENE ACY 30
   WNW SBY 25 ESE RIC 30 NE RWI 15 ENE ILM ...CONT... VRB 55 SSE FMY
   ...CONT... 40 SW PSX 15 NW LRD ...CONT... 50 WNW 3B1 20 SW ORH 25 E
   BDR.
   
   ...THERE IS A MDT RISK OF SVR TSTMS N CENTRAL AND NW TX....
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX NEWD TO IL/WRN
   INDIANA....
   
   ...SRN PLAINS AREA...
   THE CLOSED MID LEVEL LOW JUST E OF THE FOUR CORNERS WILL DRIFT ESEWD
   TODAY AND TONIGHT AND GRADUALLY EVOLVE INTO MORE OF AN OPEN WAVE IN
   RESPONSE TO UPSTREAM HEIGHT FALLS WITH A NRN STREAM TROUGH
   AMPLIFYING OVER THE NRN PLAINS.  AT THE SURFACE...A COLD FRONT IS
   MOVING SWD ACROSS THE SRN HIGH PLAINS...AND SLOWLY SEWD ACROSS
   CENTRAL OK/ERN KS/NW MO.  MUCH OF OKLAHOMA RESIDES WITHIN A MODIFIED
   OUTFLOW AIR MASS FROM OVERNIGHT CONVECTION...AND THE OUTFLOW
   BOUNDARY ASSOCIATED WITH THIS COLD POOL EXTENDS WSWWD FROM NW AR
   ACROSS SE OK TO NW TX WHERE IT INTERSECTS THE FRONT BETWEEN
   ABI-SPS-MWL.  A WEAK WAVE WILL LIKELY PERSIST THROUGH THE AFTERNOON
   NEAR THIS BOUNDARY INTERSECTION...AND THIS AREA OF NW TX SHOULD BE
   THE PRIMARY FOCUS FOR SEVERE STORM DEVELOPMENT LATER THIS AFTERNOON.
   
   
   12Z SOUNDINGS REVEAL A BROAD PLUME OF 7.5-8.5 C/KM MID LEVEL LAPSE
   RATES OVER THE SRN PLAINS...WHILE BOUNDARY LAYER DEWPOINTS IN THE
   MID-UPPER 60S ARE SPREADING NWD FROM CENTRAL INTO N/NW TX ALONG THE
   OUTFLOW BOUNDARY.  BREAKS IN THE LOW CLOUDS WILL ALLOW SUBSTANTIAL
   SURFACE HEATING AND AFTERNOON MLCAPE VALUES OF 2000-3000 J/KG ACROSS
   CENTRAL AND N/NW TX.  MEANWHILE...EXPECT WSWLY MID LEVEL FLOW TO
   GRADUALLY INCREASE THIS AFTERNOON OVER NW TX/WRN OK AS THE MID LEVEL
   LOW MOVES ESEWD OVER NRN NM...AND THE INCREASING MID LEVEL FLOW WILL
   COMBINE WITH STRONG INSTABILITY TO SUPPORT A THREAT OF SUPERCELLS
   WITH VERY LARGE HAIL AND DAMAGING WINDS.  LOW-LEVEL SHEAR WILL NOT
   BE PARTICULARLY STRONG IN THE WARM SECTOR...BUT RICH LOW-LEVEL
   MOISTURE AND LOCAL SHEAR ENHANCEMENTS ALONG THE OUTFLOW BOUNDARY
   COULD SUPPORT A COUPLE OF TORNADOES THIS AFTERNOON/EVENING.
   
   ...CENTRAL/ERN OK NEWD TO IL/INDIANA...
   THE SEVERE THREAT THIS AREA HAS BEEN MUDDLED BY THE IMPACTS OF
   OVERNIGHT AND ONGOING CONVECTION ACROSS OK/NW AR/MO.  ONE AREA OF
   SEVERE STORM POTENTIAL WILL BE FROM CENTRAL AND ERN MO ENEWD INTO IL
   THIS AFTERNOON.  A SMALL CLUSTER OF STORMS IN CENTRAL MO...POSSIBLY
   ASSOCIATED WITH A CONVECTIVELY INDUCED VORTICITY MAX...SHOULD
   DEVELOP ENEWD TOWARD IL THIS AFTERNOON.  ADDITIONAL DEVELOPMENT IS
   EXPECTED NEWD FROM THE AR STORMS INTO SE MO...AND THE COMBINED
   CONVECTIVE CLUSTER SHOULD SPREAD ENEWD TOWARD IL WITH THE THREAT OF
   ISOLATED DAMAGING WINDS AND LARGE HAIL.  LATER THIS
   AFTERNOON/EVENING...OTHER STRONG/ISOLATED SEVERE STORMS MAY FORM
   ALONG THE SURFACE FRONT FROM NE OK NEWD INTO WRN MO.  IT APPEARS
   THAT THE OVERALL SEVERE THREAT ACROSS THESE AREAS...HOWEVER...WILL
   REMAIN SOMEWHAT MARGINAL GIVEN THE RELATIVELY WEAK VERTICAL SHEAR
   AND AT BEST MODEST INSTABILITY.
   
   ...GULF COAST AREA...
   A LARGE CLUSTER OF THUNDERSTORMS PERSISTS OVER S CENTRAL/SE LA AND
   ADJACENT AREAS OF THE NRN GULF OF MEXICO.  A FEED OF RICH LOW-LEVEL
   MOISTURE FROM THE S/SW WILL SUPPORT ADDITIONAL THUNDERSTORM
   DEVELOPMENT THROUGH THIS AFTERNOON ALONG THE OUTFLOW BOUNDARY FROM S
   CENTRAL INTO NE LA...WHERE THE STRONGEST STORMS MAY PRODUCE ISOLATED
   STRONG GUSTS AND MARGINALLY SEVERE HAIL.  HOWEVER...THE OVERALL
   SEVERE THREAT SHOULD BE LIMITED BY MARGINAL VERTICAL SHEAR.
   
   ..THOMPSON.. 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 2000Z