SPC AC 041309
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0709 AM CST THU MAR 04 2004
   
   VALID 041300Z - 051200Z
   
   THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 NW
   JCT 40 SSW ABI 30 SE LTS 25 E BVO 10 WSW UNO 40 S JBR 30 SSE ELD 55
   S SHV 35 SW LFK 40 NNW VCT 15 SSW SAT 35 SSE JCT 30 NW JCT.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 SE
   P07 15 ENE MAF 25 ENE AMA 25 E HUT 35 N MLI 15 SE CGX 15 SE IND 10 N
   UOX 45 WSW 7R4 ...CONT... 45 S CRP 50 S LRD.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 E DUG 35 WSW TUS
   35 NW GBN 35 WSW PRC 20 SSE 4BL 45 SE GUC 35 NNW EHA 40 W CNK 30 SW
   FOD 30 N LSE 45 S ESC 90 E OSC.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SW BUF 35 ENE ZZV
   45 NNW JKL 30 SSE BNA 35 E JAN 45 W HUM.
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF CNTRL/NERN TX
   NEWD INTO ERN OK AND AR...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS NEWD INTO
   THE SRN GREAT LAKES...
   
   --SIGNIFICANT SEVERE WEATHER EVENT IS STILL ANTICIPATED TODAY AND
   TONIGHT FROM CNTRL TX NEWD INTO ERN OK AND AR WITH THE POTENTIAL FOR
   A FEW STRONG TORNADOES AND WIDESPREAD DAMAGING WINDS--
   
   ...SYNOPSIS...
   CLOSED MID/UPPER-LEVEL LOW TRANSLATING ENEWD ACROSS NRN MEXICO EARLY
   THIS MORNING WILL EJECT NEWD THROUGH THE SRN PLAINS AND INTO THE
   UPPER MIDWEST BY FRIDAY MORNING. ACCOMPANYING 90-100KT MID-LEVEL JET
   STREAK WILL PROPAGATE NEWD THROUGH THE TROUGH BASE WITH RESULTANT
   OVERALL TROUGH CONFIGURATION BECOMING INCREASINGLY NEGATIVE-TILTED
   WITH TIME. IN ACCORDANCE...ASSOCIATED SURFACE LOW OVER WRN TX /W OF
   SJT/ WILL DEEPEN RAPIDLY AS IT MOVES/DEVELOPS NEWD TO VICINITY OF
   LTS/SPS BY EARLY AFTERNOON AND EVENTUALLY INTO CNTRL IA BY 05/12Z.
   ATTENDANT WARM FRONT CURRENTLY FROM SURFACE LOW NEWD INTO E-CNTRL
   OK/CNTRL AR WILL LIFT NWD AHEAD OF MIGRATORY SURFACE CYCLONE...WHILE
   TRAILING PACIFIC FRONT/DRYLINE PUSHES EWD ACROSS THE SRN PLAINS TO
   THE MS RIVER BY THE END OF THE FORECAST PERIOD.
   
   ...SRN PLAINS/LOWER MS VALLEY NWD THROUGH THE MIDDLE MS VALLEY/SRN
   GREAT LAKES...
   
   VERY MOIST LOW-LEVEL AIRMASS /CHARACTERIZED BY DEWPOINTS IN THE MID
   TO UPPER 60S/ EXISTS THIS MORNING S OF RETREATING WARM FRONT OVER
   MUCH OF CNTRL/ERN TX/SERN OK AND WRN LA. STRENGTHENING SLY LLJ FROM
   CNTRL/ERN TX NWD INTO THE CNTRL LOW PLAINS/MID MS VALLEY WILL AID IN
   NWD ADVECTION OF THIS AIRMASS INTO ERN OK/AR AND SRN MO WITH 60F
   DEWPOINTS EXPECTED AS FAR N AS CNTRL MO BY EARLY EVENING. 12Z RAOBS
   SUGGEST THAT WIDESPREAD PRECIPITATION HAS DIMINISHED MID-LEVEL LAPSE
   RATES OVER PORTIONS OF ERN/NRN TX AND OK DURING THE PAST 12
   HRS...HOWEVER 12Z DRT SOUNDING WAS QUITE IMPRESSIVE WITH A 7.6 C/KM
   MID-LEVEL LAPSE RATE AND MLCAPE OF 2000 J/KG. ONGOING PRECIPITATION
   AND ANTECEDENT CLOUD COVER WILL LIMIT THE DESTABILIZATION PROCESS
   TODAY ACROSS MUCH OF OK/AR SWD INTO NRN TX WITH LIMITED DIABATIC
   HEATING AND AFOREMENTIONED MOIST BOUNDARY-LAYER CONTRIBUTING TO
   MLCAPES OF 400-800 J/KG. FARTHER S ACROSS CNTRL INTO SRN TX...THE
   STEEPER LAPSE RATES AND SOME BREAKS IN THE CLOUDS SHOULD ALLOW
   MLCAPES TO INCREASE TO 1500-2500 J/KG.
   
   CLUSTERS OF ELEVATED TSTMS WITH THE POTENTIAL FOR LARGE HAIL
   CURRENTLY FROM W TX/TX PNHDL EWD INTO OK WILL MOVE/DEVELOP NEWD INTO
   THE LOWER OH VALLEY TONIGHT. MUCAPE OF AROUND 1000 J/KG OBSERVED ON
   12Z MAF SOUNDING MAY TEND TO WEAKEN WITH NWD EXTENT...HOWEVER
   MOIST/THERMAL ADVECTION PROCESSES ON NOSE OF STRENGTHENING LLJ
   SHOULD MAINTAIN WEAKLY UNSTABLE ELEVATED AIRMASS N OF WARM FRONT
   WITH A CONTINUED THREAT OF HAIL.
   
   WITHIN THE WARM SECTOR...STORM EVOLUTION IS A BIT MORE UNCERTAIN.
   CURRENT THINKING IS THAT ONGOING TSTMS OVER WRN/SWRN TX WILL
   CONTINUE TO INCREASE IN COVERAGE/INTENSITY THROUGH THE MORNING WITH
   UPSCALE EVOLUTION INTO LINEAR MCS OCCURRING FROM SURFACE LOW SWD
   ALONG TRAILING DRYLINE/PACIFIC FRONT. CLOSE PROXIMITY TO EJECTING
   UPPER SYSTEM YIELDS LOCAL HODOGRAPHS EXHIBITING LOW-LEVEL VEERING
   BENEATH BACKING MID AND UPPER FLOW. THIS COUPLED WITH THE LINEAR
   FORCING ALONG SURFACE FRONT SUGGESTS THAT CONVECTION SHOULD REMAIN
   LARGELY OUTFLOW-DOMINANT WITH DAMAGING WINDS BEING THE PRIMARY
   THREAT OWING TO DEVELOPING COLD POOL/FAST TRANSLATIONAL SPEED OF THE
   SYSTEM.
   
   TORNADOES WILL REMAIN POSSIBLE...ESPECIALLY ALONG SURFACE LOW TRACK
   AND TAIL END OF LINE AND WITH ANY EMBEDDED SUPERCELLS/COMMA HEAD
   CONFIGURATIONS GIVEN THE STRENGTH OF THE LOW-LEVEL SHEAR. IN
   ADDITION...LARGE HAIL WILL BE MOST LIKELY WITH ANY EMBEDDED
   SUPERCELLS AND/OR ADDITIONAL STORMS THAT DEVELOP WITHIN REGION OF
   STEEPER LAPSE RATES OVER CNTRL/SRN TX NEWD ALONG TRACK OF MID-LEVEL
   COLD POOL.
   
   ADDITIONAL STORM CLUSTERS MAY DEVELOP TO THE E IN A CORRIDOR FROM
   THE EDWARDS PLATEAU/HILL COUNTRY NEWD INTO N-CNTRL/NERN TX LATER
   THIS MORNING AND AFTERNOON WITHIN FREE WARM SECTOR AS LARGE-SCALE
   FORCING OVERSPREADS INSTABILITY AXIS. HERE...PROXIMITY HODOGRAPHS
   INDICATE MORE FAVORABLE KINEMATIC PROFILES FOR CYCLIC MESOCYCLONES
   AND POSSIBLY A STRONG TORNADO OR TWO GIVEN 0-1KM SRH VALUES OF
   300-400 M2/S2 AND GREATER OVERALL HODOGRAPH LENGTH.
   
   AS 90-100KT MID-LEVEL JET STEAK LIFTS NEWD INTO THE RED RIVER VALLEY
   EARLY THIS EVENING...EXPECT THE POTENTIAL FOR WIDESPREAD DAMAGING
   WINDS TO INCREASE. MESOSCALE SYSTEM ASSOCIATED WITH SURFACE FRONTAL
   WAVE WILL RAPIDLY ACCELERATE NEWD AT THIS TIME INTO ERN OK/ERN
   TX...LIKELY OVERTAKING THE MAJORITY DISCRETE DOWNSTREAM DEVELOPMENT.
   DAMAGING WIND/ISOLATED TORNADO THREAT SHOULD THEN SPREAD NEWD ACROSS
   AR/NRN LA/SRN MO THIS EVENING...WITH MAINLY A DAMAGING WIND THREAT
   EXISTING WITH ONGOING MCS INTO THE LOWER OH VALLEY OVERNIGHT.
   
   ..MEAD/TAYLOR.. 03/04/2004
   
   ...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