SPC AC 091644
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1144 AM CDT FRI APR 09 2004
   
   VALID 091630Z - 101200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 15 W
   SEP 30 NE ABI 50 N ABI 50 SSE CDS CDS 45 SW GAG 35 E GAG END TUL 30
   SSW HRO 25 NNW LIT 30 WSW PBF 10 NNE GGG 35 N ACT 15 W SEP.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 60 W MIA 10 N VRB.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 S P07 45 SE MAF 40
   N MAF 25 W CNM 30 NW ELP 35 NNE DUG 45 NW TUS 25 S BLH 25 NW BLH 35
   NNW EED 25 SW SGU 20 NE BCE 35 S SLC 40 W MLD 30 ENE SUN 20 NE MQM
   50 SE LVM 15 NE WRL 40 SSE CPR 20 NE FCL 45 SE LIC 45 W GCK 50 E ICT
   45 NW UNO 25 NE POF 20 NE MKL 35 NE TUP 20 SSW CBM 30 NW HEZ 40 WSW
   POE 45 NNW HOU 50 E SAT 50 SSE DRT.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NRN TX AND MUCH
   OF OK INTO WRN AR......
   
   ...SYNOPSIS...
   AMPLIFIED MID/UPPER LEVEL FLOW HAS BECOME ESTABLISHED FROM THE ERN
   PACIFIC ACROSS THE ROCKIES WITH A SHARP UPPER RIDGE MOVING TOWARD
   THE WEST COAST...AND A NUMBER OF DOWNSTREAM SHORT WAVE TROUGHS
   SPREADING ESEWD ACROSS THE NRN ROCKIES...INTERMOUNTAIN WEST...AND
   THE GREAT BASIN. A DEAMPLIFYING UPPER WAVE...ACROSS KS/OK AT THIS
   TIME...WILL CONTINUE EAST TOWARD CONFLUENT FLOW OVER THE MIDWEST/MS
   VALLEY. FAST ZONAL FLOW WILL EXISTS IN THE MID LEVELS ACROSS THE
   EAST.
   
   ...SRN PLAINS...
   GIVEN COMPLEXITY OF EVOLVING PATTERN ACROSS THE WEST AND SRN
   PLAINS...CONSIDERABLE UNCERTAINTY EXISTS WITH REGARD TO SEVERE
   WEATHER POTENTIAL AND COVERAGE TODAY. THIS UNCERTAINTY IS COMPOUNDED
   BY THE EXISTENCE OF MARGINAL LOW-LEVEL MOISTURE RETURN ACROSS THE
   SOUTHERN PLAINS WITH LATEST OBSERVATIONS SHOWING LOW TO MID 50S F
   DEWPOINTS ACROSS MOST OF CNTRL/NRN TX INTO SWRN OK. TRUE MARITIME
   TROPICAL AIRMASS WILL REMAIN CONFINED TO FAR S TX. LARGE SCALE
   FORCING FOR ASCENT OVER THE SLGT RISK AREA EXPECTED TO REMAIN
   RELATIVELY WEAK WITH DOMINANT FORCING MECHANISMS FOR DEEP CONVECTION
   BEING LOCAL/MESOSCALE THERMODYNAMICS AND BOUNDARY INTERACTIONS.
   
   LATEST SURFACE ANALYSIS DEPICTS LEE-SIDE SURFACE LOW OVER SERN CO
   WITH A WARM FRONT EXTENDING SEWD TO SWRN OK...AND THEN EWD ALONG THE
   RED RIVER. AS OK/KS UPPER WAVE CONTINUES TO WEAKEN IN CONFLUENT
   UPPER FLOW REGIME...ONLY A WEAK SURFACE LOW/WAVE IS EXPECTED TO
   RIPPLE EWD ALONG THE RETREATING WARM FRONT FROM SWRN OK TO WRN AR
   THROUGH TONIGHT. MEANWHILE...PRIMARY DEEP LAYER CYCLONE SHOULD
   REMAIN IN THE LEE OF THE CENTRAL ROCKIES/SOUTHERN HIGH PLAINS AS
   UPSTREAM NRN ROCKIES/GREAT BASIN SHORT WAVES BEGIN TO CONSOLIDATE
   NEAR THE FOUR CORNERS REGION THROUGH LATE TONIGHT.
   A DRYLINE SHOULD MIX EWD ACROSS THE TX PNHDL AND NWRN TX THROUGH THE
   AFTERNOON GIVEN MODEST WLY DEEP LAYER FLOW AND STRONG HEATING OVER
   THE SRN HIGH PLAINS
   
   WITH LATEST VIS SATELLITE IMAGERY DEPICTING POTENTIAL FOR STRONG
   SURFACE HEATING ACROSS THE TX PNHDL/NWRN TX AND SRN OK...AIRMASS
   OVER THESE AREAS IS EXPECTED TO BECOME INCREASINGLY UNSTABLE AND
   WEAKLY CAPPED THROUGH LATE AFTERNOON. DESPITE LIMITED BOUNDARY LAYER
   MOISTURE...HEATING COUPLED WITH RELATIVELY COLD TEMPS ALOFT WILL
   CONTRIBUTE TO MLCAPE ON THE ORDER OF 1000-1500 J/KG AHEAD OF THE
   DRYLINE AND ALONG SOUTH OF SURFACE WARM FRONT. THIS INSTABILITY
   SHOULD CONTINUE TO FEED INTO A NARROWING ZONE OF ISENTROPIC ASCENT
   ON THE SERN EDGE OF THE UPPER WAVE...AND AHEAD OF WARM FRONTAL WAVE
   MOVING ACROSS SERN OK AND WRN AR THROUGH LATE AFTERNOON/EARLY
   EVENING. THIS SHOULD SUPPORT A POTENTIALLY EXPANDING AREA OF TSTMS
   ACROSS THESE AREAS WITH GREATEST CHANCE FOR SURFACE-BASED STORMS
   EXISTING IN PROXIMITY TO THE WARM FRONT OVER SERN OK...AND PERHAPS
   NRN TX. DIRECTIONAL SHEAR THROUGH THE STORM UPDRAFT LAYER AND DEEP
   LAYER SHEAR AROUND 40KT WILL SUPPORT SUPERCELLS. PRESENCE OF WARM
   FRONTAL ZONE WILL LOCALLY ENHANCE SRH AND MAINTAIN FAVORABLE LOW
   LEVEL CONVERGENCE FOR PERSISTENT UPDRAFTS WITH A TENDENCY TO
   PROPAGATE EWD ALONG THE BOUNDARY. LARGE HAIL AND A TORNADO OR TWO
   COULD OCCUR WITH THIS ACTIVITY.
   
   DESPITE EVEN WEAKER LARGE SCALE SUPPORT FOR ASCENT FARTHER
   WEST...ACROSS WRN OK AND NWRN TX...IT APPEARS THAT MIXING ON THE
   DRYLINE COMBINED WITH LOW LEVEL CONVERGENCE NEAR THE FRONT/DRYLINE
   INTERSECTION ACROSS NWRN OK...SHOULD BE ADEQUATE FOR AT LEAST ISOLD
   STORM INITIATION THESE AREAS INTO THE EVENING. RELATIVELY WEAK LOW
   LEVEL FLOW AND HIGH LCL/LFC THESE AREAS SUGGESTS PRIMARILY A
   HIGH-BASED SUPERCELL ENVIRONMENT WITH LARGE HAIL AND A FEW DAMAGING
   WIND GUSTS POSSIBLE.
   
   ..CARBIN.. 04/09/2004
   
   ...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