SPC AC 071107
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0507 AM CST SUN DEC 07 2003
   
   VALID 091200Z - 101200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF E TX/LA AND THE
   CNTRL GULF CST....
   
   ...SYNOPSIS...
   AN ACTIVE...AMPLIFIED AND PROGRESSIVE PATTERN EXPECTED ACROSS THE
   LWR 48 ON TUESDAY.  SHORTWAVE TROUGH NOW APPROACHING THE WA/ORE
   CST...LIKELY TO BE OVER SW TX EARLY IN THE PERIOD...SHOULD CONTINUE
   E TO THE LWR MS VLY BY LATE TUESDAY AND ASSUME A NEGATIVE TILT.  AT
   THE SAME TIME...EQUALLY POTENT UPSTREAM DISTURBANCE... NOW FORMING
   WELL S OF THE ALEUTIANS...EXPECTED TO REACH NRN CA BY 12Z WEDNESDAY.
   
   SURFACE LOW THAT WILL ACCOMPANY TX TROUGH SHOULD BE OVER CNTRL OK AT
   THE START OF THE PERIOD.  THE SYSTEM WILL LIKELY DEEPEN AND ARC NE
   INTO WRN KY/SRN IND BY 12Z WEDNESDAY.  IN THE WEST...COLD FRONT
   ASSOCIATED WITH PACIFIC LOW SHOULD MOVE INTO CNTRL CA LATE IN THE
   PERIOD.
   
   LATEST ENSEMBLE DATA SUGGEST THAT MODELS ARE MORE OR LESS CONVERGING
   ON THE STRONGER/SLOWER SOLUTION WITH THE TX TROUGH AS WAS ORIGINALLY
   FORECAST BY THE ECMWF. IN CONTRAST...CONSIDERABLE UNCERTAINTY
   REMAINS WITH SYSTEM APPROACHING THE W CST.
   
   ...E TX/WRN LA TO CNTRL GULF CST...
   A FEW CLUSTERS/BANDS OF THUNDERSTORMS MAY BE PRESENT AT THE START OF
   THE PERIOD IN WARM ADVECTION ZONE EXTENDING NNEWD FROM E TX INTO ERN
   OK/WRN AR. MOST OF THIS ACTIVITY WILL PROBABLY BE SLIGHTLY ELEVATED.
    WEAK INSTABILITY SHOULD LIMIT SEVERE THREAT... ALTHOUGH MARGINALLY
   SEVERE HAIL COULD ACCOMPANY SOME OF THE STORMS.
   
   COMBINATION OF MODEST SURFACE HEATING AND...MORE IMPORTANTLY...
   INCREASING LARGE SCALE ASCENT...SHOULD RESULT IN INTENSIFICATION/
   INCREASED ORGANIZATION OF THE STORMS AS UPPER IMPULSE APPROACHES
   REGION BY MIDDAY.  GIVEN 60+ KT MID LEVEL SW FLOW ROUNDING BASE OF
   TROUGH AND 30+ KT SLY LOW LEVEL JET...AMPLE SHEAR WILL BE PRESENT TO
   SUPPORT SUPERCELLS.  BUT SUCH ACTIVITY SHOULD REMAIN EMBEDDED WITHIN
   LINES/CLUSTERS GIVEN LINEAR NATURE OF MESOSCALE FORCING AND BACKING
   FLOW ALOFT.  IN ADDITION...PRECIPITATION INTO WEAKLY-RECOVERED
   BOUNDARY LAYER ENVIRONMENT WILL LIKELY RETARD NWD RETURN OF TRUE
   GULF AIR INTO LA.  THIS SHOULD LIMIT OVERALL DEGREE/EXTENT OF SEVERE
   THREAT.  NEVERTHELESS...BOWING SEGMENTS WITH HIGH WIND/HAIL AND
   PERHAPS A COUPLE TORNADOES COULD OCCUR WHEREVER SUSTAINED
   SURFACE-BASED STORMS DO FORM.
   
   LATER IN THE PERIOD...A LIMITED THREAT WILL EXIST FOR
   REINTENSIFICATION OF EMBEDDED CONVECTIVE BAND NEWD INTO THE LWR TN
   VLY AS UPPER SYSTEM BECOMES MORE NEGATIVELY-TILTED AND STRONG
   FRONTOGENETIC FORCING ENCOUNTERS INCREASING MOISTURE INFLOW. WHILE
   WIND FIELD WILL BE STRONG...LIMITED INSTABILITY EXPECTED TO PRECLUDE
   A THREAT FOR WIDESPREAD SEVERE.  ISOLATED SEVERE ACTIVITY
   MAY...HOWEVER...AFFECT COASTAL SECTIONS OF MS/AL AND FL DURING THIS
   TIME.
   
   ..CORFIDI.. 12/07/2003
   
   ...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 3 OUTLOOK IS SCHEDULED FOR 1200Z